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Permalink - Posted on 2021-01-15 00:00
This morning I got an encrypted email, and in the process of trying to decrypt it I discovered that I had lost my PGP key. I have no idea how I lost it. As such, I have created a new PGP key and replaced the one on my website with it. I did the replacement in this commit, which you can see is verified with a subkey of my new key.
My new PGP key ID is 803C 935A E118 A224
. The key with the ID 799F 9134 8118 1111
should not be used anymore. Here are all the subkey fingerprints:
Signature key ....: 378E BFC6 3D79 B49D 8C36 448C 803C 935A E118 A224
created ....: 2021-01-15 13:04:28
Encryption key....: 8C61 7F30 F331 D21B 5517 6478 8C5C 9BC7 0FC2 511E
created ....: 2021-01-15 13:04:28
Authentication key: 7BF7 E531 ABA3 7F77 FD17 8F72 CE17 781B F55D E945
created ....: 2021-01-15 13:06:20
General key info..: pub rsa2048/803C935AE118A224 2021-01-15 Christine Dodrill (Yubikey) <me@christine.website>
sec> rsa2048/803C935AE118A224 created: 2021-01-15 expires: 2031-01-13
card-no: 0006 03646872
ssb> rsa2048/8C5C9BC70FC2511E created: 2021-01-15 expires: 2031-01-13
card-no: 0006 03646872
ssb> rsa2048/CE17781BF55DE945 created: 2021-01-15 expires: 2031-01-13
card-no: 0006 03646872
I don't really know what the proper way is to go about revoking an old PGP key. It probably doesn't help that I don't use PGP very often. I think this is the first encrypted email I've gotten in a year.
Let's hope that I don't lose this key as easily!
Permalink - Posted on 2021-01-14 00:00
Well, so I think I found out where my Kubernetes cluster cost came from. For context, this blog gets a lot of traffic. Since the last deploy, my blog has served its RSS feed over 19,000 times. I have some pretty naiive code powering the RSS feed. It basically looked something like this:
This code was fantastically simple to develop, however it was very expensive in terms of bandwidth. When you add all this up, my RSS feed used to be more than a one megabyte response. It was also only getting larger as I posted more content.
This is unsustainable, so I have taken multiple actions to try and fix this from several angles.
Rationale: this is my most commonly hit and largest endpoint. I want to try and cut down its size.
— Cadey A. Ratio (@theprincessxena) January 15, 2021
current feed (everything): 1356706 bytes
20 posts: 177931 bytes
10 posts: 53004 bytes
5 posts: 29318 bytes pic.twitter.com/snjnn8RFh8
Mara
Yes, that graph is showing in gigabytes. We're so lucky that bandwidth is free on Hetzner.
First I finally set up the site to run behind Cloudflare. The Cloudflare settings are set very permissively, so your RSS feed reading bots or whatever should NOT be affected by this change. If you run into any side effects as a result of this change, contact me and I can fix it.
Second, I also now set cache control headers on every response. By default the "static" pages are cached for a day and the "dynamic" pages are cached for 5 minutes. This should allow new posts to show up quickly as they have previously.
Thirdly, I set up ETags for the feeds. Each of my feeds will send an ETag in a response header. Please use this tag in future requests to ensure that you don't ask for content you already have. From what I recall most RSS readers should already support this, however I'll monitor the situation as reality demands.
Lastly, I adjusted the ttl of the RSS feed so that compliant feed readers should only check once per day. I've seen some feed readers request the feed up to every 5 minutes, which is very excessive. Hopefully this setting will gently nudge them into behaving.
As a nice side effect I should have slightly lower ram usage on the blog server too! Right now it's sitting at about 58 and a half MB of ram, however with fewer copies of my posts sitting in memory this should fall by a significant amount.
If you have any feedback about this, please contact me or mention me on Twitter. I read my email frequently and am notified about Twitter mentions very quickly.
Permalink - Posted on 2021-01-09 00:00
Borg Backup is a encrypted, compressed, deduplicated backup program for multiple platforms including Linux. This combined with the NixOS options for configuring Borg Backup allows you to backup on a schedule and restore from those backups when you need to.
Borg Backup works with local files, remote servers and there are even cloud hosts that specialize in hosting your backups. In this post we will cover how to set up a backup job on a server using BorgBase's free tier to host the backup files.
You will need a few things:
First, we will need to create a SSH key for root to use when connecting to
BorgBase. Open a shell as root on the server and make a borgbackup
folder in
root's home directory:
mkdir borgbackup
cd borgbackup
Then create a SSH key that will be used to connect to BorgBase:
ssh-keygen -f ssh_key -t ed25519 -C "Borg Backup"
Ignore the SSH key password because at this time the automated Borg Backup job doesn't allow the use of password-protected SSH keys.
Now we need to create an encryption passphrase for the backup repository. Run this command to generate one using xkcdpass:
nix-shell -p python39Packages.xkcdpass --run 'xkcdpass -n 12' > passphrase
Mara
You can do whatever you want to generate a suitable passphrase, however xkcdpass is proven to be more random than most other password generators.
Now that we have the basic requirements out of the way, let's configure BorgBase
to use that SSH key. In the BorgBase UI click on the Account tab in the upper
right and open the SSH key management window. Click on Add Key and paste in the
contents of ./ssh_key.pub
. Name it after the hostname of the server you are
working on. Click Add Key and then go back to the Repositories tab in the upper
right.
Click New Repo and name it after the hostname of the server you are working on. Select the key you just created to have full access. Choose the region of the backup volume and then click Add Repository.
On the main page copy the repository path with the copy icon next to your repository in the list. You will need this below. Attempt to SSH into the backup repo in order to have ssh recognize the server's host key:
ssh -i ./ssh_key o6h6zl22@o6h6zl22.repo.borgbase.com
Then accept the host key and press control-c to terminate the SSH connection.
In your configuration.nix
file, add the following block:
services.borgbackup.jobs."borgbase" = {
paths = [
"/var/lib"
"/srv"
"/home"
];
exclude = [
# very large paths
"/var/lib/docker"
"/var/lib/systemd"
"/var/lib/libvirt"
# temporary files created by cargo and `go build`
"**/target"
"/home/*/go/bin"
"/home/*/go/pkg"
];
repo = "o6h6zl22@o6h6zl22.repo.borgbase.com:repo";
encryption = {
mode = "repokey-blake2";
passCommand = "cat /root/borgbackup/passphrase";
};
environment.BORG_RSH = "ssh -i /root/borgbackup/ssh_key";
compression = "auto,lzma";
startAt = "daily";
};
Customize the paths and exclude lists to your needs. Once you are satisfied,
rebuild your NixOS system using nixos-rebuild
:
nixos-rebuild switch
And then you can fire off an initial backup job with this command:
systemctl start borgbackup-job-borgbase.service
Monitor the job with this command:
journalctl -fu borgbackup-job-borgbase.service
The first backup job will always take the longest to run. Every incremental backup after that will get smaller and smaller. By default, the system will create new backup snapshots every night at midnight local time.
To restore files, first figure out when you want to restore the files from. NixOS includes a wrapper script for each Borg job you define. you can mount your backup archive using this command:
mkdir mount
borg-job-borgbase mount o6h6zl22@o6h6zl22.repo.borgbase.com:repo ./mount
Then you can explore the backup (and with it each incremental snapshot) to your heart's content and copy files out manually. You can look through each folder and copy out what you need.
When you are done you can unmount it with this command:
borg-job-borgbase umount /root/borgbase/mount
And that's it! You can get more fancy with nixops using a setup like this. In general though, you can get away with this setup. It may be a good idea to copy down the encryption passphrase onto paper and put it in a safe space like a safety deposit box.
For more information about Borg Backup on NixOS, see the relevant chapter of the NixOS manual or the list of borgbackup options that you can pick from.
I hope this is able to help.
Permalink - Posted on 2021-01-04 00:00
hlang (the h language) is a revolutionary new use of WebAssembly that enables single-paridigm programming without any pesky state or memory accessing. The simplest program you can use in hlang is the h world program:
h
When run in the hlang playground, you can see its output:
h
To get more output, separate multiple h's by spaces:
h h h h
This returns:
h
h
h
h
For internationalization concerns, hlang also supports the Lojbanic h '
. You can
mix h and '
to your heart's content:
' h '
This returns:
'
h
'
Finally an easy solution to your pesky Lojban internationalization problems!
For maximum understandability, compiler errors are provided in Lojban. For example this error tells you that you have an invalid character at the first character of the string:
h: gentoldra fi'o zvati fe li no
Here is an interlinear gloss of that error:
h: gentoldra fi'o zvati fe li no
grammar-wrong existing-at second-place use-number 0
And now you are fully fluent in hlang, the most exciting programming language since sliced bread.
Permalink - Posted on 2021-01-03 00:00
Well, since I posted that last post I have had an adventure. A good friend pointed out a server host that I had missed when I was looking for other places to use, and now I have migrated my blog to this new server. As of yesterday, I now run my website on a dedicated server in Finland. Here is the story of my journey to migrate 6 years of cruft and technical debt to this new server.
Let's talk about this goliath of a server. This server is an AX41 from Hetzner.
It has 64 GB of ram, a 512 GB nvme drive, 3 2 TB drives, and a Ryzen 3600. For
all practical concerns, this beast is beyond overkill and rivals my workstation
tower in everything but the GPU power. I have named it lufta
, which is the
word for feather in L'ewa.
For my server setup process, the first step it to assimilate it. In this step I get a base NixOS install on it somehow. Since I was using Hetzner, I was able to boot into a NixOS install image using the process documented here. Then I decided that it would also be cool to have this server use zfs as its filesystem to take advantage of its legendary subvolume and snapshotting features.
So I wrote up a bootstrap system definition like the Hetzner tutorial said and
ended up with hosts/lufta/bootstrap.nix
:
{ pkgs, ... }:
{
services.openssh.enable = true;
users.users.root.openssh.authorizedKeys.keys = [
"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPg9gYKVglnO2HQodSJt4z4mNrUSUiyJQ7b+J798bwD9 cadey@shachi"
];
networking.usePredictableInterfaceNames = false;
systemd.network = {
enable = true;
networks."eth0".extraConfig = ''
[Match]
Name = eth0
[Network]
# Add your own assigned ipv6 subnet here here!
Address = 2a01:4f9:3a:1a1c::/64
Gateway = fe80::1
# optionally you can do the same for ipv4 and disable DHCP (networking.dhcpcd.enable = false;)
Address = 135.181.162.99/26
Gateway = 135.181.162.65
'';
};
boot.supportedFilesystems = [ "zfs" ];
environment.systemPackages = with pkgs; [ wget vim zfs ];
}
Then I fired up the kexec tarball and waited for the server to boot into a NixOS
live environment. A few minutes later I was in. I started formatting the drives
according to the NixOS install
guide with
one major difference: I added a /boot
ext4 partition on the SSD. This allows
me to have the system root device on zfs. I added the disks to a raidz1
pool
and created a few volumes. I also added the SSD as a log device so I get SSD
caching.
From there I installed NixOS as normal and rebooted the server. It booted normally. I had a shiny new NixOS server in the cloud! I noticed that the server had booted into NixOS unstable as opposed to NixOS 20.09 like my other nodes. I thought "ah, well, that probably isn't a problem" and continued to the configuration step.
Mara
That's ominous...
Now that the server was assimilated and I could SSH into it, the next step was to configure it to run my services. While I was waiting for Hetzner to provision my server I ported a bunch of my services over to Nixops services a-la this post in this folder of my configs repo.
Now that I had them, it was time to add this server to my Nixops setup. So I
opened the nixops definition
folder and
added the metadata for lufta
. Then I added it to my Nixops deployment with
this command:
$ nixops modify -d hexagone -n hexagone *.nix
Then I copied over the autogenerated config from lufta
's /etc/nixos/
folder
into
hosts/lufta
and
ran a nixops deploy
to add some other base configuration.
Once that was done, I started enabling my services and pushing configs to test them. After I got to a point where I thought things would work I opened up the Kubernetes console and started deleting deployments on my kubernetes cluster as I felt "safe" to migrate them over. Then I saw the deployments come back. I deleted them again and they came back again.
Oh, right. I enabled that one Kubernetes service that made it intentionally hard to delete deployments. One clever set of scale-downs and kills later and I was able to kill things with wild abandon.
I copied over the gitea data with rsync
running in the kubernetes deployment.
Then I killed the gitea deployment, updated DNS and reran a whole bunch of gitea
jobs to resanify the environment. I did a test clone on a few of my repos and
then I deleted the gitea volume from DigitalOcean.
Moving over the other deployments from Kubernetes into NixOS services was
somewhat easy, however I did need to repackage a bunch of my programs and static
sites for NixOS. I made the
pkgs
tree a bit more
fleshed out to compensate.
Mara
Okay, packaging static sites in NixOS is beyond overkill, however a lot of them need some annoyingly complicated build steps and throwing it all into Nix means that we can make them reproducible and use one build system to rule them all. Not to mention that when I need to upgrade the system, everything will rebuild with new system libraries to avoid the Docker bitrot problem.
After a significant portion of the services were moved over, I decided it was
time to do the reboot test. I ran the reboot
command and then...nothing.
My continuous ping test was timing out. My phone was blowing up with downtime
messages from NodePing. Yep, I messed something up.
I was able to boot the server back into a NixOS recovery environment using the kexec trick, and from there I was able to prove the following:
I was confused. This shouldn't be happening. After half an hour of troubleshooting, I gave in and ordered an IPKVM to be installed in my server.
Once that was set up (and I managed to trick MacOS into letting me boot a .jnlp web start file), I rebooted the server so I could see what error I was getting on boot. I missed it the first time around, but on the second time I was able to capture this screenshot:
Then it hit me. I did the install on NixOS unstable. My other servers use NixOS 20.09. I had downgraded zfs and the older version of zfs couldn't mount the volume created by the newer version of zfs in read/write mode. One more trip to the recovery environment later to install NixOS unstable in a new generation.
Then I switched my tower's default NixOS channel to the unstable channel and ran
nixops deploy
to reactivate my services. After the NodePing uptime
notifications came in, I ran the reboot test again while looking at the console
output to be sure.
It booted. It worked. I had a stable setup. Then I reconnected to IRC and passed out.
Here is a list of all of the services I have migrated over from my old dedicated server, my kubernetes cluster and my dokku server:
Doing this migration is a bit of an archaeology project as well. I was continuously discovering services that I had littered over my machines with very poorly documented requirements and configuration. I hope that this move will let the next time I do this kind of migration be a lot easier by comparison.
I still have a few other services to move over, however the ones that are left are much more annoying to set up properly. I'm going to get to deprovision 5 servers in this migration and as a result get this stupidly powerful goliath of a server to do whatever I want with and I also get to cut my monthly server costs by over half.
I am very close to being able to turn off the Kubernetes cluster and use NixOS for everything. A few services that are still on the Kubernetes cluster are resistant to being nixified, so I may have to use the Docker containers for that. I was hoping to be able to cut out Docker entirely, however we don't seem to be that lucky yet.
Sure, there is some added latency with the server being in Europe instead of Montreal, however if this ever becomes a practical issue I can always launch a cheap DigitalOcean VPS in Toronto to act as a DNS server for my WireGuard setup.
Either way, I am now off Kubernetes for my highest traffic services. If services
of mine need to use the disk, they can now just use the disk. If I really care
about the data, I can add the service folders to the list of paths to back up to
rsync.net
(I have a post about how this backup process works in the drafting
stage) via borgbackup.
Let's hope it stays online!
Many thanks to Graham Christensen, Dave Anderson and everyone else who has been helping me along this journey. I would be lost without them.
Permalink - Posted on 2020-12-31 00:00
Right now I am using a freight train to mail a letter when it comes to hosting my web applications. If you are reading this post on the day it comes out, then you are connected to one of a few replicas of my site code running across at least 3 machines in my Kubernetes cluster. This certainly works, however it is not very ergonomic and ends up being quite expensive.
I think I made a mistake when I decided to put my cards into Kubernetes for my personal setup. It made sense at the time (I was trying to learn Kubernetes and I am cursed into learning by doing), however I don't think it is really the best choice available for my needs. I am not a large company. I am a single person making things that are really targeted for myself. I would like to replace this setup with something more at my scale. Here are a few options I have been exploring combined with their pros and cons.
Here are the services I currently host on my Kubernetes cluster:
irc.within.website
)My goal in evaluating other options is to reduce cost and complexity. Kubernetes is a very complicated system and requires a lot of hand-holding and rejiggering to make it do what you want. NixOS, on the other hand, is a lot simpler overall and I would like to use it for running my services where I can.
Cost is a huge factor in this. My Kubernetes setup is a money pit. I want to prioritize cost reduction as much as possible.
I could do nothing about this and eat the complexity as a cost of having this website and those other services online. However over the year or so I've been using Kubernetes I've had to do a lot of hacking at it to get it to do what I want.
I set up the cluster using Terraform and Helm 2. Helm 3 is the current (backwards-incompatible) release, and all of the things that are managed by Helm 2 have resisted being upgraded to Helm 3.
I'm going to say something slightly controversial here, but YAML is a HORRIBLE format for configuration. I can't trust myself to write unambiguous YAML. I have to reference the spec constantly to make sure I don't have an accidental Norway/Ontario bug. I have a Dhall package that takes away most of the pain, however it's not flexible enough to describe the entire scope of what my services need to do (IE: pinging Google/Bing to update their indexes on each deploy), and I don't feel like putting in the time to make it that flexible.
Mara
This is the regex for determining what is a valid boolean value in YAML:
y|Y|yes|Yes|YES|n|N|no|No|NO|true|True|TRUE|false|False|FALSE|on|On|ON|off|Off|OFF
. This can bite you eventually. See the Norway Problem for more information.
I have a tor hidden service endpoint for a few of my services. I have to use an unmaintained tool to manage these on Kubernetes. It works today, but the Kubernetes operator API could change at any time (or the API this uses could be deprecated and removed without much warning) and leave me in the dust.
I could live with all of this, however I don't really think it's the best idea going forward. There's a bunch of services that I added on top of Kubernetes that are dangerous to upgrade and very difficult (if not impossible) to downgrade when something goes wrong during the upgrade.
One of the big things that I have with this setup that I would have to rebuild in NixOS is the continuous deployment setup. However I've done that before and it wouldn't really be that much of an issue to do it again.
NixOS fixes all the jank I mentioned above by making my specifications not have to include the version numbers of everything the system already provides. You can actually trust the package repos to have up to date packages. I don't have to go around and bump the versions of shims and pray they work, because with NixOS I don't need them anymore.
This is a doable option. The main problem here would be doing the provision step. SoYouStart and Kimsufi (both are offshoot/discount brands of OVH) have very little in terms of customization of machine config. They work best when you are using "normal" distributions like Ubuntu or CentOS and leave them be. I would want to run NixOS on it and would have to do several trial and error runs with a tool such as nixos-infect to assimilate the server into running NixOS.
With this option I would get the most storage out of any other option by far. 4 TB is a lot of space. However, SoYouStart and Kimsufi run decade-old hardware at best. I would end up paying a lot for very little in the CPU department. For most things I am sure this would be fine, however some of my services can have CPU needs that might exceed what second-generation Xeons can provide.
SoYouStart and Kimsufi have weird kernel versions though. The last SoYouStart
dedi I used ran Fedora and was gimped with a grsec kernel by default. I had to
end up writing this gem of a systemd service on
boot
which did a kexec
to boot into a
non-gimped kernel on boot. It was a huge hack and somehow worked every time. I
was still afraid to reboot the machine though.
Sure is a lot of ram for the cost though.
This shares most of the problems as the SoYouStart or Kimsufi nodes. However, nixos-infect is known to have a higher success rate on Digital Ocean droplets. It would be really nice if Digital Ocean let you upload arbitrary ISO files and go from there, but that is apparently not the world we live in.
8 GB of ram would be way more than enough for what I am doing with these services.
Vultr is probably my top pick for this. You can upload an arbitrary ISO file, kick off your VPS from it and install it like normal. I have a little shell server shared between some friends built on top of such a Vultr node. It works beautifully.
The fact that it has the same cost as the Digital Ocean droplet just adds to the perfection of this option.
Here is the cost table I've drawn up while comparing these options:
Option | Ram | Disk | Cost per month | Hacks |
---|---|---|---|---|
Do nothing | 6 GB (4 GB usable) | Not really usable, volumes cost extra | $60/month | Very Yes |
SoYouStart | 32 GB | 2x2TB SAS | $40/month | Yes |
Kimsufi | 32 GB | 2x2TB SAS | $35/month | Yes |
Digital Ocean | 8 GB | 160 GB SSD | $40/month | On provision |
Vultr | 8 GB | 160 GB SSD | $40/month | No |
I think I am going to go with the Vultr option. I will need to modernize some of my services to support being deployed in NixOS in order to do this, however I think that I will end up creating a more robust setup in the process. At least I will create a setup that allows me to more easily maintain my own backups rather than just relying on DigitalOcean snapshots and praying like I do with the Kubernetes setup.
Thanks farcaller, Marbles, John Rinehart and others for reviewing this post prior to it being published.
Permalink - Posted on 2020-12-28 00:00
Over the long weekend I found out about a program called GB Studio. It's a simple drag-and-drop interface that you can use to make homebrew games for the Nintendo Game Boy. I was intrigued and I had some time, so I set out to make a little top-down adventure game. After a few days of tinkering I came up with an idea and created Mara: Sh0rk of Justice.
Mara
You made a game about me? :D
Guide Mara through the spooky dungeon in order to find all of its secrets. Seek out the secrets of the spooks! Defeat the evil mage! Solve the puzzles! Find the items of power! It's up you to save us all, Mara!
You can play it in an <iframe>
on itch.io!
Game development is hard. Even with tools that help you do it, there's a limit to how much you can get done at once. Everything links together. You really need to test things both in isolation and as a cohesive whole.
I cannot compose music to save my life. I used free-to-use music assets from the GB Studio Community Assets pack to make this game. I think I managed to get everything acceptable.
GB Studio is rather inflexible. It feels like it's there to really help you get started from a template. Even though you can make the whole game from inside GB Studio, I probably should have ejected the engine to source code so I could customize some things like the jump button being weird in platforming sections.
Pixel art is an art of its own. I used a lot of free to use assets from itch.io for the tileset and a few NPC's. The rest was created myself using Aseprite. Getting Mara's walking animation to a point that I thought was acceptable was a chore. I found a nice compromise though.
Overall I'm happy with the result as a whole. Try it out, see how you like it and please do let me know what I can improve on for the future.
Permalink - Posted on 2020-12-25 00:00
After hours of work and adjustment, I have finally finished version 1 of my tabletop roleplaying game The Source. It is available on itch.io with an added 50% discount for readers of my blog. This discount will only last for the next two weeks.
Patrons (of any price tier) can claim a free copy here. Your support gives me so much.
Merry christmas all.
Permalink - Posted on 2020-12-19 00:00
You know what, fuck rules. Fuck systems. Fuck limitations. Let's dial the tabletop RPG system down to its roots. Let's throw out every stat but one: Awesomeness. When you try to do something that could fail, roll for Awesomeness. If your roll is more than your awesomeness stat, you win. If not, you lose. If you are or have something that would benefit you in that situation, roll for awesomeness twice and take the higher value.
No stats.
No counts.
No limits.
No gods.
No masters.
Just you and me and nature in the battlefield.
Etc. Don't think too hard. Let a roll of the dice decide if you are unsure.
Here are some probably balanced awesomeness base stats depending on what kind of dice you are using:
Here's an example character sheet:
Name:
Awesomeness:
Race:
Class:
Inventory:
*
That's it. You don't even need the race or class if you don't want to have it.
You can add more if you feel it is relevant for your character. If your character is a street brat that has experience with haggling, then fuck it be the most street brattiest haggler you can. Try to not overload your sheet with information, this game is supposed to be simple. A sentence or two at most is good.
The World is a character that other systems would call the Narrator, the Pathfinder, Dungeon Master or similar. Let's strip this down to the core of the matter. One player doesn't just dictate the world, they are the world.
The World also controls the monsters and non-player characters. In general, if you are in doubt as to who should roll for an event, The World does that roll.
These are things you can do to make the base game even more tailored to your group. Whether you should do this is highly variable to the needs and whims of your group in particular.
So, one problem that could come up with this is that bad luck could make this not as fun. As a result, add these two rules in:
This should add up so that luck would even out over time. Players that have less luck than usual will eventually get their awesomeness evened out so that luck will be in their favor.
In this mod, rip out Awesomeness altogether. When two parties are at odds, they both roll dice. The one that rolls higher gets what they want. If they tie, both people get a little part of what they want. For extra fun do this with six-sided dice.
Use your imagination! Ask others if you are unsure!
This is not essential but it may help.
Okay so basically monsters fall into two categories: peons and bosses. Peons should be easy to defeat, usually requiring one action. Bosses may require more and might require more than pure damage to defeat. Get clever. Maybe require the players to drop a chandelier on the boss. Use the environment.
In general, peons should have a very high base awesomeness in order to do things they want. Bosses can vary based on your mood.
Adjustable awesomeness should affect monsters too.
Take a setting from somewhere and roll with it. You want to do a cyberpunk jaunt in Night City with a sword-wielding warlock, a succubus space marine, a bard netrunner and a shapeshifting monk? Do the hell out of that. That sounds awesome.
Don't worry about accuracy or the like. You are setting out to have fun.
Special thanks goes to Jared, who sent out this tweet that inspired this document. In case the tweet gets deleted, here's what it said:
heres a d&d for you
you have one stat, its a saving throw. if you need to roll dice, you roll your save.
you have a class and some equipment and junk. if the thing you need to roll dice for is relevant to your class or equipment or whatever, roll your save with advantage.
oh your Save is 5 or something. if you do something awesome, raise your save by 1.
no hp, save vs death. no damage, save vs goblin. no tracking arrows, save vs running out of ammo.
thanks to @Axes_N_Orcs for this
What's So Cool About Save vs Death?
can you carry all that treasure and equipment? save vs gains
I replied:
Can you get more minimal than this?
He replied:
when two or more parties are at odds, all roll dice. highest result gets what they want.
hows that?
This document is really just this twitter exchange in more words so that people less familiar with tabletop games can understand it more easily. You know you have finished when there is nothing left to remove, not when you can add something to "fix" it.
I might put this on my itch.io page.
Permalink - Posted on 2020-12-14 00:00
NOTE: This is a very different kind of post compared to what I usually write. If you or anyone you know works at Twitter, please link this to them. I am in a unique situation and the normal account recovery means do not work. If you work at Twitter and are reading this, my case number is [redacted].
EDIT(19:51 M12 14 2020): My account is back. Thank you anonymous Twitter support people. For everyone else, please take this as an example of how NOT to handle account issues. The fact that I had to complain loudly on Twitter to get this weird edge case taken care of is ludicrous. I'd gladly pay Twitter just to have a support mechanism that gets me an actual human without having to complain on Twitter.
On Sunday, December 13, 2020, I noticed that I was locked out of my Twitter account. If you go to @theprincessxena today, you will see that the account is locked out for "unusual activity". I don't know what I did to cause this to happen (though I have a few theories) and I hope to explain them in the headings below. I have gotten no emails or contact from Twitter about this yet. I have a backup account at @CadeyRatio as a stopgap. I am also on mastodon as @cadey@mst3k.interlinked.me.
In place of my tweeting about quarantine life, I am writing about my experiences here.
I can't unlock my account the normal way because I forgot to set up two factor authentication and I also forgot to change the phone number registered with the account to my Canadian one when I moved to Canada. I remembered to do this change for all of the other accounts I use regularly except for my Twitter account.
In order to stop having to pay T-Mobile $70 per month, I transferred my phone number to Twilio. This combined with some clever code allowed me to gracefully migrate to my new Canadian number. Unfortunately, Twitter flat-out refuses to send authentication codes to Twilio numbers. It's probably to prevent spam, but it would be nice if there was an option to get the authentication code over a phone call.
Recently I needed to travel internationally in order to start my new job at Tailscale. Due to an unfortunate series of events over two months, I needed to actually travel internationally to get a new visa. This lead me to take a very boring trip to Minnesota for a week.
During that trip, I tweeted and fleeted about my travels. I took pictures and was in my hotel room a lot.
Mara
We can't dig up the link for obvious reasons, but one person said they were always able to tell when we are traveling because it turns the twitter account into a fast food blog.
I think Twitter may have locked out my account because I was suddenly in Minnesota after being in Canada for almost a year.
I use mi as part of my new blogpost announcement pipeline. One of the things mi does is submits new blogposts and some metadata about them to Twitter. I haven't been able to find any logs to confirm this, but if something messed up in a place that was unlogged somehow, it could have triggered some kind of anti-abuse pipeline.
One of my recent tweets that I can't find anymore is a tweet about a NixOS screenshot for my work machine. I think that some part of the algorithm somewhere really hated it, and thus triggered the account lock. I don't really understand how a screenshot of KDE 5 showing neofetch output could make my account get locked, but with enough distributed machine learning anything can happen.
I used a random password generated with iCloud for my Twitter password. Theoretically this could have been broken, but I doubt it.
Overall, I just want to be able to tweet again. Please spread this around for reach. I don't like using my blog to reach out like this, but I've been unable to find anyone that knows someone at Twitter so far and I feel this is the best way to broadcast it. I'll update this post with the resolution to this problem when I get one.
I think the International Travel theory is the most likely scenario. I just want a human to see this situation and help fix it.
Permalink - Posted on 2020-12-04 00:00
The project I formerly called wasmcloud has now been renamed to Trisiel after the discovery of a name conflict. The main domain for Trisiel is now https://trisiel.com to avoid any confusions between our two projects.
Planning for implementing and hosting Trisiel is still in progress. I will give more updates as they are ready to be released. To get more up to the minute information please follow the twitter account @trisielcloud, I will be posting there as I have more information.
I am limitless. There is no cage or constraint that can corral me into one constant place. I am limitless. I can change, shift, overcome, transform, because I am not bound to a thing that serves me, and my body serves me.
Quantusum, James Mahu
Permalink - Posted on 2020-12-02 00:00
Recently in my Various Updates post I announced that my website had gotten WebMention support. Today I implemented WebMention integration into blog articles, allowing you to see where my articles are mentioned across the internet. This will not work with every single mention of my site, but if your publishing platform supports sending WebMentions, then you will see them show up on the next deploy of my site.
Thanks to the work of the folks at Bridgy, I have been able to also keep track of mentions of my content across Twitter, Reddit and Mastodon. My WebMention service will also attempt to resolve Bridgy mention links to their original sources as much as it can. Hopefully this should allow you to post my articles as normal across those networks and have those mentions be recorded without having to do anything else.
As I mentioned before, this is implemented on top of
mi. mi receives mentions sent to
https://mi.within.website/api/webmention/accept
and will return a reference
URL in the Location
header. This will return JSON-formatted data about the
mention. Here is an example:
$ curl https://mi.within.website/api/webmention/01ERGGEG7DCKRH3R7DH4BXZ6R9 | jq
{
"id": "01ERGGEG7DCKRH3R7DH4BXZ6R9",
"source_url": "https://maya.land/responses/2020/12/01/i-think-this-blog-post-might-have-been.html",
"target_url": "https://christine.website/blog/toast-sandwich-recipe-2019-12-02",
"title": null
}
This is all of the information I store about each WebMention. I am working on title detection (using the readability algorithm), however I am unable to run JavaScript on my scraper server. Content that is JavaScript only may not be able to be scraped like this.
Many thanks to Chris Aldrich for inspiring me to push this feature to the end. Any articles that don't have any WebMentions yet will link to the WebMention spec.
Be well.
Permalink - Posted on 2020-11-30 00:00
Recently I needed to set up a Discord message on a cronjob as a part of moderating a guild I've been in for years. I've done this before using cronjobs, however this time we will be using NixOS and systemd timers. Here's what you will need to follow along:
Mara
If you don't have moderation permissions in any guilds, make your own for testing! You will need the "Manage Webhooks" permission to create a webhook.
systemd timers are like cronjobs, except they trigger systemd services instead of shell commands. For this example, let's create a daily webhook reminder to check on your Animal Crossing island at 9 am.
Let's create the systemd service at the end of the machine's
configuration.nix
:
systemd.services.acnh-island-check-reminder = {
serviceConfig.Type = "oneshot";
script = ''
MESSAGE="It's time to check on your island! Check those stonks!"
WEBHOOK="${builtins.readFile /home/cadey/prefix/secrets/acnh-webhook-secret}"
USERNAME="Domo"
${pkgs.curl}/bin/curl \
-X POST \
-F "content=$MESSAGE" \
-F "username=$USERNAME" \
"$WEBHOOK"
'';
};
Mara
This service is a oneshot unit, meaning systemd will launch this once and not expect it to always stay running.
Now let's create a timer for this service. We need to do the following:
Add this to the end of your configuration.nix
:
systemd.timers.acnh-island-check-reminder = {
wantedBy = [ "timers.target" ];
partOf = [ "acnh-island-check-reminder.service" ];
timerConfig.OnCalendar = "TODO(Xe): this";
};
Before we mentioned that we want to trigger this reminder every morning at 9 am. systemd timers specify their calendar config in the following format:
DayOfWeek Year-Month-Day Hour:Minute:Second
So for something that triggers every day at 9 AM, it would look like this:
*-*-* 8:00:00
Mara
You can ignore the day of the week if it's not relevant!
So our final timer definition would look like this:
systemd.timers.acnh-island-check-reminder = {
wantedBy = [ "timers.target" ];
partOf = [ "acnh-island-check-reminder.service" ];
timerConfig.OnCalendar = "*-*-* 8:00:00";
};
Now we can deploy this with nixos-rebuild
:
$ sudo nixos-rebuild switch
You should see a line that says something like this in the nixos-rebuild
output:
starting the following units: acnh-island-check-reminder.timer
Let's test the service out using systemctl
:
$ sudo systemctl start acnh-island-check-reminder.service
And you should then see a message on Discord. If you don't see a message, check
the logs using journalctl
:
$ journalctl -u acnh-island-check-reminder.service
If you see an error that looks like this:
curl: (26) Failed to open/read local data from file/application
This usually means that you tried to do a role or user mention at the beginning of the message and curl tried to interpret that as a file input. Add a word like "hey" at the beginning of the line to disable this behavior. See here for more information.
Also happy December! My site has the snow CSS loaded for the month. Enjoy!
Permalink - Posted on 2020-11-25 00:00
On November 22, I sent a tweet that contained the following text:
#467662 #207768 #7A7A6C #6B2061 #6F6C20 #6D7079
#7A6120 #616C7A #612E20 #5A6C6C #206F61 #61773A
#2F2F6A #6C6168 #6A6C68 #752E6A #736269 #2F6462
#796675 #612E6E #747020 #6D7679 #207476 #796C20
#70756D #767974 #686170 #76752E
This was actually the first part of a scavenger hunt/mini CTF that I had set up in order to see who went down the rabbit hole to solve it. I've had nearly a dozen people report back to me telling that they solved all of the puzzles and nearly all of them said they had a lot of fun. Here's how to solve each of the layers of the solution and how I created them.
The first layer was that encoded tweet. If you notice, everything in it is
formatted as HTML color codes. HTML color codes just so happen to be encoded in
hexadecimal. Looking at the codes you can see 20
come up a lot, which happens
to be the hex-encoded symbol for the spacebar. So, let's turn this into a
continuous hex string with s/#//g
and s/ //g
:
Mara
If you've seen a
%20
in a URL before, that is the URL encoded form of the spacebar!
4676622077687A7A6C6B20616F6C206D7079
7A6120616C7A612E205A6C6C206F6161773A
2F2F6A6C61686A6C68752E6A7362692F6462
796675612E6E7470206D7679207476796C20
70756D76797468617076752E
And then turn it into an ASCII string:
Fvb whzzlk aol mpyza alza. Zll oaaw://jlahjlhu.jsbi/dbyfua.ntp mvy tvyl pumvythapvu.
Mara
Wait, what? this doesn't look like much of anything...wait, look at the
oaaw://
. Could that behttp://
?
Indeed it is my perceptive shark friend! Let's decode the rest of the string using the Caeser Cipher:
You passed the first test. See http://cetacean.club/wurynt.gmi for more information.
Now we're onto something!
Opening http://cetacean.club/wurynt.gmi we see the following:
wurynt
a father of modern computing,
rejected by his kin,
for an unintentional sin,
creator of a machine to break
the cipher that this message is encoded inbq cr di ej kw mt os px uz gh
VI 1 1 I 17 1 III 12 1
qghja xmbzc fmqsb vcpzc zosah tmmho whyph lvnjj mpdkf gbsjl tnxqf ktqia mwogp eidny awoxj ggjqz mbrcm tkmyd fogzt sqkga udmbw nmkhp jppqs xerqq gdsle zfxmq yfdfj kuauk nefdc jkwrs cirut wevji pumqt hrxjr sfioj nbcrc nvxny vrphc r
Correction for the last bit
gilmb egdcr sowab igtyq pbzgv gmlsq udftc mzhqz exbmx zaxth isghc hukhc zlrrk cixhb isokt vftwy rfdyl qenxa nljca kyoej wnbpf uprgc igywv qzuud hrxzw gnhuz kclku hefzk xtdpk tfjzu byfyi sqmel gweou acwsi ptpwv drhor ahcqd kpzde lguqt wutvk nqprx gmiad dfdcm dpiwb twegt hjzdf vbkwa qskmf osjtk tcxle mkbnv iqdbe oejsx lgqc
Mara
Hmm, "a father of computing", "rejected by his kin", "an unintentional sin", "creator of a machine to break a cipher" could that mean Alan Turing? He made something to break the Enigma cipher and was rejected by the British government for being gay right?
Indeed. Let's punch these settings into an online enigma machine and see what we get:
congr adula tions forfi gurin goutt hisen igmao famys teryy ouhav egott enfar
thert hanan yonee lseha sbefo rehel pmebr eakfr eefol lowth ewhit erabb ittom
araht tpyvz vgjiu ztkhf uhvjq roybx dswzz caiaq kgesk hutvx iplwa donio n
httpc olons lashs lashw hyvec torze dgamm ajayi ndigo ultra zedfi vetan gokil
ohalo fineu ltrah alove ctorj ayqui etrho omega yotta betax raysi xdonu tseve
nsupe rwhyz edzed canad aasia indig oasia twoqu ietki logam maeps ilons uperk
iloha loult rafou rtang ovect orsev ensix xrayi ndigo place limaw hyasi adelt
adoto nion
And here is where I messed up with this challenge. Enigma doesn't handle
numbers. It was designed to encode the 26 letters of the Latin alphabet. If you
look at the last bit of the output you can see onio n
and o nion
. This
points you to a Tor hidden
service, but because
I messed this up the two hints point you at slightly wrong onion addresses (tor
hidden service addresses usually have numbers in them). Once I realized this, I
made a correction that just gives away the solution so people could move on to
the next step.
Onwards to http://yvzvgjiuz5tkhfuhvjqroybx6d7swzzcaia2qkgeskhu4tv76xiplwad.onion/!
Open your tor browser and punch in the onion URL. You should get a page that looks like this:
This shows some confusing combinations of letters and some hexadecimal text. We'll get back to the hexadecimal text in a moment, but let's take a closer look at the letters. There is a hint here to search the plover dictionary. Plover is a tool that allows hobbyists to learn stenography to type at the rate of human speech. My moonlander has a layer for typing out stenography strokes, so let's enable it and type them out:
Follow the white rabbit
Go to/test. w a s m
Which we can reinterpret as:
Follow the white rabbit
Go to /test.wasm
Mara
The joke here is that many people seem to get stenography and steganography confused, so that's why there's stenography in this steganography challenge!
Going to /test.wasm we get a WebAssembly download. I've uploaded a copy to my blog's CDN here.
Going back to that hexadecimal text from above, we see that it says this:
go get tulpa.dev/cadey/hlang
This points to the source repo of hlang, which is
a satirical "programming language" that can only print the letter h
(or the
lojbanic h '
for that sweet sweet internationalisation cred). Something odd
about hlang is that it uses WebAssembly to execute
all programs written in it (this helps it reach its "no sandboxing required" and
"zero* dependencies" goals).
Let's decompile this WebAssembly file with
wasm2wat
$ wasm2wat /data/test.wasm
<output too big, see https://git.io/Jkyli>
Looking at the decompilation we can see that it imports a host function h.h
as
the hlang documentation suggests and then constantly calls it a bunch of times:
(module
(type (;0;) (func (param i32)))
(type (;1;) (func))
(import "h" "h" (func (;0;) (type 0)))
(func (;1;) (type 1)
i32.const 121
call 0
i32.const 111
call 0
i32.const 117
call 0
; ...
There's a lot of 32
in the output. 32
is the base 10 version of 0x20
,
which is the space character in ASCII. Let's try to reformat the numbers to
ascii characters and see what we get:
you made it, this is the end of the line however. writing all of this up takes a lot of time. if you made it this far, email me@christine.website to get your name entered into the hall of heroes. be well.
Each layer was designed independently and then I started building them together later.
One of the first steps was to create the website for Mara's Realm. I started by
writing out all of the prose into a file called index.md
and then I ran
sw using Pandoc for
markdown conversion.
Then I created the WebAssembly binary by locally hacking a copy of hlang to
allow arbitrary strings. I stuck it in the source directory for the website and
told sw
to not try and render it as markdown.
Once I had the HTML source, I copied it to a machine on my network at
/srv/http/marahunt
using this command:
$ rsync \
-avz \
site.static/ \
root@192.168.0.127:/srv/http/marahunt
And then I created a tor hidden service using the services.tor.hiddenServices options:
services.tor = {
enable = true;
hiddenServices = {
"hunt" = {
name = "hunt";
version = 3;
map = [{
port = 80;
toPort = 80;
}];
};
};
};
Once I pushed this config to that server, I grabbed the hostname from
/var/lib/tor/onion/hunt/hostname
and set up an nginx virtualhost:
services.nginx = {
virtualHosts."yvzvgjiuz5tkhfuhvjqroybx6d7swzzcaia2qkgeskhu4tv76xiplwad.onion" =
{
root = "/srv/http/marahunt";
};
};
And then I pushed the config again and tested it with curl:
$ curl -H "Host: yvzvgjiuz5tkhfuhvjqroybx6d7swzzcaia2qkgeskhu4tv76xiplwad.onion" http://127.0.0.1 | grep title
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 3043 100 3043 0 0 2971k 0 --:--:-- --:--:-- --:--:-- 2971k
<title>Mara's Realm</title>
.headerSubtitle { font-size: 0.6em; font-weight: normal; margin-left: 1em; }
<a href="index.html">Mara's Realm</a> <span class="headerSubtitle">sh0rk in the cloud</span>
Once I was satisfied with the HTML, I opened up an enigma encoder and started writing out the message congradulating the user for figuring out "this enigma of a mystery". I also included the onion URL (with the above mistake) in that message.
Then I started writing the wurynt page on my gemini server. wurynt was coined by blindly pressing 6 keys on my keyboard. I added a little poem about Alan Turing to give a hint that this was an enigma cipher and then copied the Enigma settings on the page just in case. It turned out that I was using the default settings for the Cryptee Enigma simulator, so this was not needed; however it was probably better to include them regardless.
This is where I messed up as I mentioned earlier. Once I realized my mistake in trying to encode the onion address twice, I decided it would be best to just give away the answer on the page, so I added the correct onion URL to the end of the enigma message so that it wouldn't break flow for people.
The final part was to write and encode the message that I would tweet out. I opened a scratch buffer and wrote out the "You passed the first test" line and then encoded it using the ceasar cipher and encoded the result of that into hex. After a lot of rejiggering and rewriting to make it have a multiple of 3 characters of text, I reformatted it as HTML color codes and tweeted it without context.
Some of the emails and twitter DM's I got had some useful and amusing feedback. Here's some of my favorites:
my favourite part was the opportunity to go down different various rabbit holes (I got to learn about stenography and WASM, which I'd never looked into!)
I want to sleep. It's 2 AM here, but a friend sent me the link an hour ago and I'm a cat, so the curiosity killed me.
That was a fun little game. Thanks for putting it together.
oh noooo this is going to nerd snipe me
I'm amused that you left the online enigma emulator on default settings.
I swear to god I'm gonna beach your orca ass
Next time I'd like to try and branch out from just using ascii. I'd like to throw other encodings into the game (maybe even have a stage written in EBCDIC formatted Esperanto or something crazy like that). I was also considering having some public/private key crypto in the mix to stretch people's skillsets.
Something I will definitely do next time is make sure that all of the layers are solveable. I really messed up with the enigma step and I had to unblock people by DMing them the answer. Always make sure your puzzles can be solved.
(in no particular order)
Thank you for solving this! I'm happy this turned out so successfully. More to come in the future.
🙂
Permalink - Posted on 2020-11-20 00:00
When setting up services on your home network, sometimes you have questions along the lines of "how do I know that things are working?". In this blogpost we will go over a few tools that you can use to monitor and visualize your machine state so you can answer that. Specifically we are going to use the following tools to do this:
Let's get going!
Mara
Something to note: in here you might see domains using the
.pele
top-level domain. This domain will likely not be available on your home network. See this series on how to set up something similar for your home network. If you don't have such a setup, replace anything that ends in.pele
with whatever you normally use for this.
Grafana is a service that handles graphing and alerting. It also has some nice tools to create dashboards. Here we will be using it for a few main purposes:
Let's configure Grafana on a machine. Open that machine's configuration.nix
in
an editor and add the following to it:
# hosts/chrysalis/configuration.nix
{ config, pkgs, ... }: {
# grafana configuration
services.grafana = {
enable = true;
domain = "grafana.pele";
port = 2342;
addr = "127.0.0.1";
};
# nginx reverse proxy
services.nginx.virtualHosts.${config.services.grafana.domain} = {
locations."/" = {
proxyPass = "http://127.0.0.1:${toString config.services.grafana.port}";
proxyWebsockets = true;
};
};
}
Mara
If you have a custom TLS Certificate Authority, you can set up HTTPS for this deployment. See here for an example of doing this. If this server is exposed to the internet, you can use a certificate from Let's Encrypt instead of your own Certificate Authority.
Then you will need to deploy it to your cluster with nixops deploy
:
$ nixops deploy -d home
Now open the Grafana server in your browser at http://grafana.pele and login with the super secure default credentials of admin/admin. Grafana will ask you to change your password. Please change it to something other than admin.
This is all of the setup we will do with Grafana for now. We will come back to it later.
Prometheus was punished by the gods by giving the gift of knowledge to man. He was cast into the bowels of the earth and pecked by birds. Oracle Turret, Portal 2
Prometheus is a service that reads metrics from other services, stores them and
allows you to search and aggregate them. Let's add it to our configuration.nix
file:
# hosts/chrysalis/configuration.nix
services.prometheus = {
enable = true;
port = 9001;
};
Now let's deploy this config to the cluster with nixops deploy
:
$ nixops deploy -d home
And let's configure Grafana to read from Prometheus. Open Grafana and click on
the gear to the left side of the page. The Data Sources
tab should be active.
If it is not active, click on Data Sources
. Then click "add data source" and
choose Prometheus. Set the URL to http://127.0.0.1:9001
(or with whatever port
you configured above) and leave everything set to the default values. Click
"Save & Test". If there is an error, be sure to check the port number.
Now let's start getting some data into Prometheus with the node exporter.
The Prometheus node exporter exposes a lot of information about systems ranging from memory, disk usage and even systemd service information. There are also some other collectors you can set up based on your individual setup, however we are going to enable only the node collector here.
In your configuration.nix
, add an exporters block and configure the node
exporter under services.prometheus
:
# hosts/chrysalis/configuration.nix
services.prometheus = {
exporters = {
node = {
enable = true;
enabledCollectors = [ "systemd" ];
port = 9002;
};
};
}
Now we need to configure Prometheus to read metrics from this exporter. In your
configuration.nix
, add a scrapeConfigs
block under services.prometheus
that points to the node exporter we configured just now:
# hosts/chrysalis/configuration.nix
services.prometheus = {
# ...
scrapeConfigs = [
{
job_name = "chrysalis";
static_configs = [{
targets = [ "127.0.0.1:${toString config.services.prometheus.exporters.node.port}" ];
}];
}
];
# ...
}
# ...
Mara
The complicated expression in the target above allows you to change the port of the node exporter and ensure that Prometheus will always be pointing at the right port!
Now we can deploy this to your cluster with nixops:
$ nixops deploy -d home
Open the Explore tab in Grafana and type in the following expression:
node_memory_MemFree_bytes
and hit shift-enter (or click the "Run Query" button in the upper left side of the screen). You should see a graph showing you the amount of ram that is free on the host, something like this:
If you want to query other fields, you can type in node_
into the searchbox
and autocomplete will show what is available. For a full list of what is
available, open the node exporter metrics route in your browser and look through
it.
Now that we have all of this information about our machine, let's create a little dashboard for it and set up a few alerts.
Click on the plus icon on the left side of the Grafana UI to create a new dashboard. It will look something like this:
In Grafana terminology, everything you see in a dashboard is inside a panel. Let's create a new panel to keep track of memory usage for our server. Click "Add New Panel" and you will get a screen that looks like this:
Let's make this keep track of free memory. Write "Memory Free" in the panel title field on the right. Write the following query in the textbox next to the dropdown labeled "Metrics":
node_memory_MemFree_bytes
and set the legend to {{job}}
. You should get a graph that looks something
like this:
This will show you how much memory is free on each machine you are monitoring with Prometheus' node exporter. Now let's configure an alert for the amount of free memory being low (where "low" means less than 64 megabytes of ram free).
Hit save in the upper right corner of the Grafana UI and give your dashboard a name, such as "Home Cluster Status". Now open the "Memory Free" panel for editing (click on the name and then click "Edit"), click the "Alert" tab, and click the "Create Alert" button. Let's configure it to do the following:
You can do that with a configuration like this:
Save the changes to apply this config.
Mara
Wait a minute. Where will this alert go to?
It will only show up on the alerts page:
But we can add a notification channel to customize this. Click on the Notification Channels tab and then click "New Channel". It should look something like this:
You can send notifications to many services, but let's send one to Discord this time. Acquire a Discord webhook link from somewhere and paste it in the Webhook URL field. Name it something like "Discord". It may also be a good idea to make this the default notification channel using the "Default" checkbox under the Notification Settings, so that our existing alert will show up in Discord when the system runs out of memory.
You can configure other alerts like this so you can monitor any other node metrics you want.
Mara
You can also monitor for the lack of data on particular metrics. If something that should always be reported suddenly isn't reported, it may be a good indicator that a server went down. You can also add other services to your
scrapeConfigs
settings so you can monitor things that expose metrics to Prometheus at/metrics
.
Now that we have metrics configured, let's enable Loki for logging.
Loki is a log aggregator created by the people behind Grafana. Here we will use
it as a target for all system logs. Unfortunately, the Loki NixOS module is very
basic at the moment, so we will need to configure it with our own custom yaml
file. Create a file in your configuration.nix
folder called loki.yaml
and
copy in the config from this
gist:
Then enable Loki with your config in your configuration.nix
file:
# hosts/chrysalis/configuration.nix
services.loki = {
enable = true;
configFile = ./loki-local-config.yaml;
};
Promtail is a tool made by the Loki team that sends logs into Loki. Create a
file called promtail.yaml
in the same folder as configuration.nix
with the
following contents:
server:
http_listen_port: 28183
grpc_listen_port: 0
positions:
filename: /tmp/positions.yaml
clients:
- url: http://127.0.0.1:3100/loki/api/v1/push
scrape_configs:
- job_name: journal
journal:
max_age: 12h
labels:
job: systemd-journal
host: chrysalis
relabel_configs:
- source_labels: ['__journal__systemd_unit']
target_label: 'unit'
Now we can add promtail to your configuration.nix
by creating a systemd
service to run it with this snippet:
# hosts/chrysalis/configuration.nix
systemd.services.promtail = {
description = "Promtail service for Loki";
wantedBy = [ "multi-user.target" ];
serviceConfig = {
ExecStart = ''
${pkgs.grafana-loki}/bin/promtail --config.file ${./promtail.yaml}
'';
};
};
Now that you have this all set up, you can push this to your cluster with nixops:
$ nixops deploy -d home
Once that finishes, open up Grafana and configure a new Loki data source with
the URL http://127.0.0.1:3100
:
Now that you have Loki set up, let's query it! Open the Explore view in Grafana
again, choose Loki as the source, and enter in the query {job="systemd-journal"}
:
Mara
You can also add Loki queries like this to dashboards! Loki also lets you query by systemd unit with the
unit
field. If you wanted to search for logs fromfoo.service
, you would need a query that looks something like{job="systemd-journal", unit="foo.service"}
You can do many more complicated things with Loki. Look here for more information on what you can query. As of the time of writing this blogpost, you are currently unable to make Grafana alerts based on Loki queries as far as I am aware.
This barely scrapes the surface of what you can accomplish with a setup like this. Using more fancy setups you can alert on the rate of metrics changing. I plan to make NixOS modules to make this setup easier in the future. There is also a set of options in services.grafana.provision that can make it easier to automagically set up Grafana with per-host dashboards, alerts and all of the data sources that are outlined in this post.
The setup in this post is quite meager, but it should be enough to get you started with whatever you need to monitor. Adding Prometheus metrics to your services will go a long way in terms of being able to better monitor things in production, do not be afraid to experiment!
Permalink - Posted on 2020-11-18 00:00
Immigration purgatory is an experience. It's got a lot of waiting and there is a lot of uncertainty that can make it feel stressful. Like I said before, I'm not concerned; however I have a lot of free time on my hands and I've been using it to make some plans for the blog (and a new offering for companies that need help dealing with the new Docker Hub rate limits) in the future. I'm gonna outline them below in their own sections. This blogpost was originally about 4 separate blogposts that I started and abandoned because I had trouble focusing on finishing them. Stress sucks lol.
I recently deployed mi v1.0.0 to my home cluster. mi is a service that handles a lot of personal API tasks including the automatic post notifications to Twitter and Mastodon. The old implementation was in Go and stored its data in RethinkDB. I also have a snazzy frontend in Elm for mi. This new version is rewritten from scratch to use Rust, Rocket and SQLite. It is also fully nixified and is deployed to my home cluster via a NixOS module.
One of the major new features I have in this rewrite is
WebMention support. WebMentions allow
compatible websites to "mention" my articles or other pages on my main domains
by sending a specially formatted HTTP request to mi. I am still in the early
stages of integrating mi into my site code, but eventually I hope to have a list
of places that articles are mentioned in each post. The WebMention endpoint for
my site is https://mi.within.website/api/webmention/accept
. I have added
WebMention metadata into the HTML source of the blog pages as well as in the
Link
header as the W3 spec demands.
If you encounter any issues with this feature, please let me know so I can get it fixed as soon as possible.
Elm is an interesting language for making single page applications. The old version of mi was the first time I had really ever used Elm for anything serious and after some research I settled on using elm-spa as a framework to smooth over some of the weirder parts of the language. elm-spa worked great at first. All of the pages were separated out into their own components and the routing setup was really intuitive (if a bit weird because of the magic involved). It's worked great for a few years and has been very low maintenance.
However when I was starting to implement the backend of mi in Rust, I tried to nixify the elm-spa frontend I made. This was a disaster. The magic that elm-spa relied on fell apart and at the time I attempted to do this it was very difficult to do this.
As a result I ended up rewriting the frontend in very very boring Elm using information from the Elm Guide and a lot of blogposts and help from the Elm slack. Overall this was a successful experiment and I can easily see this new frontend (which I have named sina as a compound toki pona pun) becoming a powerful tool for investigating and managing the data in mi.
Mara
Special thanks to malinoff, wolfadex, chadtech and mfeineis on the Elm slack for helping with the weird issues involved in getting a split model approach working.
Feel free to check out the code here. I may try to make an Elm frontend to my site for people that use the Progressive Web App support.
elm2nix is a very nice tool that lets you generate Nix definitions from Elm packages, however the template it uses is a bit out of date. To fix it you need to do the following:
$ elm2nix init > default.nix
$ elm2nix convert > elm-srcs.nix
$ elm2nix snapshot
Then open default.nix
in your favorite text editor and change this:
buildInputs = [ elmPackages.elm ]
++ lib.optional outputJavaScript nodePackages_10_x.uglify-js;
to this:
buildInputs = [ elmPackages.elm ]
++ lib.optional outputJavaScript nodePackages.uglify-js;
and this:
uglifyjs $out/${module}.${extension} --compress 'pure_funcs="F2,F3,F4,F5,F6,F7,F8,F9,A2,A3,A4,A5,A6,A7,A8,A9",pure_getters,keep_fargs=false,unsafe_comps,unsafe' \
| uglifyjs --mangle --output=$out/${module}.min.${extension}
to this:
uglifyjs $out/${module}.${extension} --compress 'pure_funcs="F2,F3,F4,F5,F6,F7,F8,F9,A2,A3,A4,A5,A6,A7,A8,A9",pure_getters,keep_fargs=false,unsafe_comps,unsafe' \
| uglifyjs --mangle --output $out/${module}.min.${extension}
These issues should be fixed in the next release of elm2nix.
As I mentioned in the past, I am looking into developing out other characters for my blog. I am still in the early stages of designing this, but I think the next character in my blog is going to be an anthro snow leopard named Alicia. I want Alicia to be a beginner that is very new to computer programming and other topics, which would then make Mara into more of a teacher type. I may also introduce my own OC Cadey (the orca looking thing you can see here or in the favicon of my site) into the mix to reply to these questions in something more close to the Socratic method.
Some people have joked that the introduction of Mara turned my blog into a shark visual novel that teaches you things. This sounds hilarious to me, and I am looking into what it would take to make an actual visual novel on a page on my blog using Rust and WebAssembly. I am in very early planning stages for this, so don't expect this to come out any time soon.
My Gergoplex kit finally came in yesterday, and I got to work soldering it up with some switches and applying the keycaps.
I picked the Pro Red linear switches with a 35 gram spring in them (read: they need 35 grams of force to actuate, which is lighter than most switches) and typing on it is buttery smooth. The keycaps are a boring black, but they look nice on it.
Overall this kit (with the partial board, switches and keycaps) cost me about US$124 (not including shipping) with the costs looking something like this:
Name | Count | Cost |
---|---|---|
Gergoplex Partial Kit | 1 | $70 |
Choc Pro Red 35g switches | 4 | $10 |
Keycaps (15) | 3 | $30 |
Braided interconnect cable | 1 | $7 |
Mini-USB cable | 1 | $7 |
I'd say this was a worthwhile experience. I haven't really soldered anything since I was in high school and it was fun to pick up the iron again and make something useful. If you are looking for a beginner soldering project, I can't recommend the Gergoplex enough.
I also picked up some extra switches and keycaps (prices not listed here) for a future project involving an eInk display. More on that when it is time.
You may have noticed that some of my projects have default branches named main
and others have default branches named mara
. This difference is very
intentional. Repos with the default branch main
generally contain code that is
"stable" and contains robust and reusable code. Repos with the default branch
mara
are generally my experimental repos and the code in them may not be the
most reusable across other projects. mi is a repo with a mara
default branch
because it is a very experimental thing. In the future I may promote it up to
having a main
branch, however for now it's less effort to keep things the way
it is.
The new Docker Hub rate limits have thrown a wrench into many CI/CD setups as well as uncertainty in how CI services will handle this. Many build pipelines implictly trust the Docker Hub to be up and that it will serve the appropriate image so that your build can work. Many organizations use their own Docker registry (GHCR, AWS/Google Cloud image registries, Artifactory, etc.), however most image build definitions I've seen start out with something like this:
FROM golang:alpine
which will implicitly pull from the Docker Hub. This can lead to bad things.
If you would like to have a call with me for examining your process for building Docker images in CI and get a list of actionable suggestions for how to work around this, contact me so that we can discuss pricing and scheduling.
I have been using Docker for my entire professional career (way back since Docker required you to recompile your kernel to enable cgroup support in public beta) and I can also discuss methods to make your Docker images as small as they can possibly get. My record smallest Docker image is 5 MB.
If either of these prospects interest you, please contact me so we can work something out.
Here's hoping that the immigration purgatory ends soon. I'm lucky enough to have enough cash built up that I can weather this jobless month. I've been using this time to work on personal projects (like mi and wasmcloud) and better myself. I've also done a little writing that I plan to release in the future after I clean it up.
In retrospect I probably should have done NaNoWriMo seeing that I basically will have the entire month of November jobless. I've had an idea for a while about someone that goes down the rabbit hole of mysticism and magick, but I may end up incorporating that into the visual novel project I mentioned in the Elm section.
Be well and stay safe out there. Wear a mask, stay at home.
Permalink - Posted on 2020-11-09 00:00
My homelab has a few NixOS machines. Right now they mostly run services inside Docker, because that has been what I have done for years. This works fine, but persistent state gets annoying*. NixOS has a tool called Nixops that allows you to push configurations to remote machines. I use this for managing my fleet of machines, and today I'm going to show you how to create service deployments with Nixops and push them to your servers.
Mara
Pedantically, Docker offers volumes to simplify this, but it is very easy to accidentally delete Docker volumes. Plain disk files like we are going to use today are a bit simpler than docker volumes, and thusly a bit harder to mess up.
For this example, let's deploy a chatbot. To make things easier, let's assume the following about this chatbot:
default.nix
that builds the service and
includes any supporting files it might needI will also need to assume that you have a git repo (or at least a folder) with all of your configuration similar to mine.
For this example I'm going to use withinbot as the service we will deploy via Nixops. withinbot is a chatbot that I use on my own Discord guild that does a number of vital functions including supplying amusing facts about printers:
<Cadey~> ~printerfact
<Within[BOT]> @Cadey~ Printers, especially older printers, do get cancer. Many
times this disease can be treated successfully
We will need to do a few major things for defining this service:
In order for the program to be installed to the remote system, you need to tell
the system how to import it. There's many ways to do this, but the cheezy way is
to add the packages to
nixpkgs.config.packageOverrides
like this:
nixpkgs.config = {
packageOverrides = pkgs: {
within = {
withinbot = import (builtins.fetchTarball
"https://github.com/Xe/withinbot/archive/main.tar.gz") { };
};
};
};
And now we can access it as pkgs.within.withinbot
in the rest of our config.
Mara
In production circumstances you should probably use a fetcher that locks to a specific version using unique URLs and hashing, but this will work enough to get us off the ground in this example.
In your configuration folder, create a folder that you will use for these
service definitions. I made mine in common/services
. In that folder, create a
default.nix
with the following contents:
{ config, lib, ... }:
{
imports = [ ./withinbot.nix ];
users.groups.within = {};
}
The group listed here is optional, but I find that having a group like that can help you better share resources and files between services.
Now we need a folder for storing secrets. Let's create that under the services folder:
$ mkdir secrets
And let's also add a gitignore file so that we don't accidentally commit these secrets to the repo:
# common/services/secrets/.gitignore
*
Now we can put any secrets we want in the secrets folder without the risk of committing them to the git repo.
Let's create withinbot.nix
and set it up:
{ config, lib, pkgs, ... }:
with lib; {
options.within.services.withinbot.enable =
mkEnableOption "Activates Withinbot (the furryhole chatbot)";
config = mkIf config.within.services.withinbot.enable {
};
}
This sets up an option called within.services.withinbot.enable
which will only
add the service configuration if that option is set to true
. This will allow
us to define a lot of services that are available, but none of their config will
be active unless they are explicitly enabled.
Now, let's create a user account for the service:
# ...
config = ... {
users.users.withinbot = {
createHome = true;
description = "github.com/Xe/withinbot";
isSystemUser = true;
group = "within";
home = "/srv/within/withinbot";
extraGroups = [ "keys" ];
};
};
# ...
This will create a user named withinbot
with the home directory
/srv/within/withinbot
, the group within
and also in the group keys
so the
withinbot user can read deployment secrets.
Now let's add the deployment secrets to the configuration:
# ...
config = ... {
users.users.withinbot = { ... };
deployment.keys.withinbot = {
text = builtins.readFile ./secrets/withinbot.env;
user = "withinbot";
group = "within";
permissions = "0640";
};
};
# ...
Assuming you have the configuration at ./secrets/withinbot.env
, this will
register the secrets into /run/keys/withinbot
and also create a systemd
oneshot service named withinbot-key
. This allows you to add the secret's
existence as a condition for withinbot to run. However, Nixops puts these keys
in /run
, which by default is mounted using a temporary memory-only filesystem,
meaning these keys will need to be re-added to machines when they are rebooted.
Fortunately, nixops reboot
will automatically add the keys back after the
reboot succeeds.
Now that we have everything else we need, let's add the service configuration:
# ...
config = ... {
users.users.withinbot = { ... };
deployment.keys.withinbot = { ... };
systemd.services.withinbot = {
wantedBy = [ "multi-user.target" ];
after = [ "withinbot-key.service" ];
wants = [ "withinbot-key.service" ];
serviceConfig = {
User = "withinbot";
Group = "within";
Restart = "on-failure"; # automatically restart the bot when it dies
WorkingDirectory = "/srv/within/withinbot";
RestartSec = "30s";
};
script = let withinbot = pkgs.within.withinbot;
in ''
# load the environment variables from /run/keys/withinbot
export $(grep -v '^#' /run/keys/withinbot | xargs)
# service-specific configuration
export CAMPAIGN_FOLDER=${withinbot}/campaigns
# kick off the chatbot
exec ${withinbot}/bin/withinbot
'';
};
};
# ...
This will create the systemd configuration for the service so that it starts on
boot, waits to start until the secrets have been loaded into it, runs withinbot
as its own user and in the within
group, and throttles the service restart so
that it doesn't incur Discord rate limits as easily. This will also put all
withinbot logs in journald, meaning that you can manage and monitor this service
like you would any other systemd service.
In your target server's configuration.nix
file, add an import of your services
directory:
{
# ...
imports = [
# ...
/home/cadey/code/nixos-configs/common/services
];
# ...
}
And then enable the withinbot service:
{
# ...
within.services = {
withinbot.enable = true;
};
# ...
}
Mara
Make that a block so you can enable multiple services at once like this!
Now you are free to deploy it to your network with nixops deploy
:
$ nixops deploy -d hexagone
And then you can verify the service is up with systemctl status
:
$ nixops ssh -d hexagone chrysalis -- systemctl status withinbot
● withinbot.service
Loaded: loaded (/nix/store/7ab7jzycpcci4f5wjwhjx3al7xy85ka7-unit-withinbot.service/withinbot.service; enabled; vendor preset: enabled)
Active: active (running) since Mon 2020-11-09 09:51:51 EST; 2h 29min ago
Main PID: 12295 (withinbot)
IP: 0B in, 0B out
Tasks: 13 (limit: 4915)
Memory: 7.9M
CPU: 4.456s
CGroup: /system.slice/withinbot.service
└─12295 /nix/store/qpq281hcb1grh4k5fm6ksky6w0981arp-withinbot-0.1.0/bin/withinbot
Nov 09 09:51:51 chrysalis systemd[1]: Started withinbot.service.
This basic template is enough to expand out to anything you would need and is what I am using for my own network. This should be generic enough for most of your needs. Check out the NixOS manual for more examples and things you can do with this. The Nixops manual is also a good read. It can also set up deployments with VirtualBox, libvirtd, AWS, Digital Ocean, and even Google Cloud.
The cloud is the limit! Be well.
Permalink - Posted on 2020-11-06 00:00
I am nowhere near qualified to review things objectively. Therefore this blogpost will mostly be about what I like about this keyboard. I plan to go into a fair bit of detail, however please do keep in mind that this is subjective as all hell. Also keep in mind that this is partially also going to be a review of my own keyboard layout too. I'm going to tackle this in a few parts that I will label with headings.
This review is NOT sponsored. I paid for this device with my own money. I have no influence pushing me either way on this keyboard.
Mara
That 3d printed brain is built from the 3D model that was made as a part of this blogpost.
I like the Moonlander. It gets out of my way and lets me focus on writing and code. I don't like how limited the Oryx configurator is, but the fact that I can build my own firmware from source and flash it to the keyboard on my own makes up for that. I think this was a purchase well worth making, but I can understand why others would disagree. I can easily see this device becoming a core part of my workflow for years to come.
The Moonlander is a solid keyboard. Once you set it up with the tenting legs and adjust the key cluster, the keyboard is rock solid. The only give I've noticed is because my desk mat is made of a rubber-like material. The construction of the keyboard is all plastic but there isn't any deck flex that I can tell. Compare this to cheaper laptops where the entire keyboard bends if you so much as touch the keys too hard.
The palmrests are detachable and when they are off it gives the keyboard a space-age vibe to it:
The palmrests feel very solid and fold up into the back of the keyboard for travel. However folding up the palmrest does mess up the tenting stability, so you can't fold in the palmrest and type very comfortably. This makes sense though, the palmrest is made out of smooth plastic so it feels nicer on the hands.
ZSA said that iPad compatibility is not guaranteed due to the fact that the iPad might not put out enough juice to run it, however in my testing with an iPad Pro 2018 (12", 512 GB storage) it works fine. The battery drains a little faster, but the Moonlander is a much more active keyboard than the smart keyboard so I can forgive this.
I've been using mechanical keyboards for years, but most of them have been clicky switches (such as cloned Cherry MX blues, actual legit Cherry MX blues and the awful Razer Green switches). This is my first real experience with Cherry MX brown switches. There are many other options when you are about to order a moonlander, but I figured Cherry MX browns would be a nice neutral choice.
The keyswitches are hot-swappable (no disassembly or soldering required), and changing out keyswitches DOES NOT void your warranty. I plan to look into Holy Pandas and Zilents V2 in the future. There is even a clever little tool in the box that makes it easy to change out keyswitches.
Overall, this has been one of the best typing experiences I have ever had. The noise is a little louder than I would have liked (please note that I tend to bottom out the keycaps as I type, so this may end up factoring into the noise I experience); but overall I really like it. It is far better than I have ever had with clicky switches.
The Moonlander uses an ortholinear layout as opposed to the staggered layout that you find on most keyboards. This took some getting used to, but I have found that it is incredibly comfortable and natural to write on.
Each side of the keyboard has the following:
;
, ,
, .
and /
like normal
keyboards)In total, this keyboard has 72 keys, making it about a 70% keyboard (assuming the math in my head is right).
My keymap uses all but two of these keys. The two keys I haven't figured out how
to best use yet are the ones that I currently have the [
and ]
keycaps on.
Right now they are mapped to the left and right arrow keys. This was the
default.
My keymap is organized into layers. In each of these subsections I will go into detail about what these layers are, what they do and how they help me. My keymap code is here and I have a limited view of it embedded below:
If you want to flash my layout to your Moonlander for some reason, you can find the firmware binary here. You can then flash this to your keyboard with Wally.
I have a few base layers that contain the main set of letters and numbers that I type. The main base layer is my Colemak layer. I have the keys arranged to a standard Colemak layout and it is currently the layer I type the fastest on. I have the RGB configured so that it is mostly pink with the homerow using a lighter shade of pink. The color codes come from my logo that you can see in the favicon or here for a larger version.
I also have a qwerty layer for gaming. Most games expect qwerty keyboards and this is an excellent stopgap to avoid having to rebind every game that I want to play. The left side of the keyboard is the active one with the controller board in it too, so I can unplug the other half of the keyboard and give my mouse a lot of room to roam.
Thanks to a friend of mine, I am also playing with Dvorak. I have not gotten far in Dvorak yet, but it is interesting to play with.
I'll cover the leader key in the section below dedicated to it, but the other major thing that I have is a colon key on my right hand thumb cluster. This has been a huge boon for programming. The colon key is typed a lot. Having it on the thumb cluster means that I can just reach down and hit it when I need to. This makes writing code in Go and Rust so much easier.
If you look at the base layer keymap, you will see that I do not have square
brackets mapped anywhere there. Yet I write code with it effortlessly. This is
because of the symbol/number layer that I access with the lower right and lower
left keys on the keyboard. I have it positioned there so I can roll my hand to
the side and then unlock the symbols there. I have access to every major symbol
needed for programming save <
and >
(which I can easily access on the base
layer with the shift key). I also get a nav cluster and a number pad.
I also have dynamic macros on this layer which function kinda like vim macros. The only difference is that there's only two macros instead of many like vim. They are convenient though.
One of the cooler parts of the Moonlander is that it can act as a mouse. It is a very terrible mouse (understandably, mostly because the digital inputs of keypresses cannot match the analog precision of a mouse). This layer has an arrow key cluster too. I normally use the arrow keys along the bottom of the keyboard with my thumbs, but sometimes it can help to have a dedicated inverse T arrow cluster for things like old MS-DOS games.
I also have media control keys here. They aren't the most useful on my linux desktop, however when I plug it into my iPad they are amazing.
I use dwm as my main window manager in Linux. dwm is entirely controlled using the keyboard. I have a dedicated keyboard layer to control dwm and send out its keyboard shortcuts. It's really nice and lets me get all of the advantages of my tiling setup without needing to hit weird keycombos.
Leader macros are one of the killer features of my layout. I have a huge bank of them and use them to do type out things that I type a lot. Most common git and Kubernetes commands are just a leader macro away.
The Go if err != nil
macro that got me on /r/programmingcirclejerk twice is
one of my leader macros, but I may end up promoting it to its own key if I keep
getting so much use out of it (maybe one of the keys I don't use can become my
if err != nil
key). I'm sad that the threads got deleted (I love it when my
content gets on there, it's one of my favorite subreddits), but such is life.
When I got this keyboard, flashed the firmware and plugged it in, I noticed that my keyboard was sending weird inputs. It was rendering things that look like this:
The quick brown fox jumps over the lazy yellow dog.
into this:
Ghf qluce bpywk tyx nlm;r yvfp ghf iazj jfiiyw syd.
This is because I had configured my NixOS install to interpret the keyboard as if it was Colemak. However the keyboard is able to lie and sends out normal keycodes (even though I am typing them in Colemak) as if I was typing in qwerty. This double Colemak meant that a lot of messages and commands were completely unintelligible until I popped into my qwerty layer.
I quickly found the culprit in my config:
console.useXkbConfig = true;
services.xserver = {
layout = "us";
xkbVariant = "colemak";
xkbOptions = "caps:escape";
};
This config told the X server to always interpret my keyboard as if it was Colemak, meaning that I needed to tell it not to. As a stopgap I commented this section of my config out and rebuilt my system.
X11 allows you to specify keyboard configuration for keyboards individually by
device product/vendor names. The easiest way I know to get this information is
to open a terminal, run dmesg -w
to get a constant stream of kernel logs,
unplug and plug the keyboard back in and see what the kernel reports:
[242718.024229] usb 1-2: USB disconnect, device number 8
[242948.272824] usb 1-2: new full-speed USB device number 9 using xhci_hcd
[242948.420895] usb 1-2: New USB device found, idVendor=3297, idProduct=1969, bcdDevice= 0.01
[242948.420896] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[242948.420897] usb 1-2: Product: Moonlander Mark I
[242948.420898] usb 1-2: Manufacturer: ZSA Technology Labs
[242948.420898] usb 1-2: SerialNumber: 0
The product is named Moonlander Mark I
, which means we can match for it and
tell X11 to not colemakify the keycodes using something like this:
Section "InputClass"
Identifier "moonlander"
MatchIsKeyboard "on"
MatchProduct "Moonlander"
Option "XkbLayout" "us"
Option "XkbVariant" "basic"
EndSection
Mara
For more information on what you can do in an
InputClass
section, see here in the X11 documentation.
This configuration fragment can easily go in the normal X11 configuration folder, but doing it like this would mean that I would have to manually drop this file in on every system I want to colemakify. This does not scale and defeats the point of doing this in NixOS.
Thankfully NixOS has an option to solve this very problem. Using this module we can write something like this:
services.xserver = {
layout = "us";
xkbVariant = "colemak";
xkbOptions = "caps:escape";
inputClassSections = [
''
Identifier "yubikey"
MatchIsKeyboard "on"
MatchProduct "Yubikey"
Option "XkbLayout" "us"
Option "XkbVariant" "basic"
''
''
Identifier "moonlander"
MatchIsKeyboard "on"
MatchProduct "Moonlander"
Option "XkbLayout" "us"
Option "XkbVariant" "basic"
''
];
};
But this is NixOS and that allows us to go one step further and make the identifier and product matching string configurable as will with our own NixOS options. Let's start by lifting all of that above config into its own module:
# Colemak.nix
{ config, lib, ... }: with lib; {
options = {
cadey.colemak = {
enable = mkEnableOption "Enables colemak for the default X config";
};
};
config = mkIf config.cadey.Colemak.enable {
services.xserver = {
layout = "us";
xkbVariant = "colemak";
xkbOptions = "caps:escape";
inputClassSections = [
''
Identifier "yubikey"
MatchIsKeyboard "on"
MatchProduct "Yubikey"
Option "XkbLayout" "us"
Option "XkbVariant" "basic"
''
''
Identifier "moonlander"
MatchIsKeyboard "on"
MatchProduct "Moonlander"
Option "XkbLayout" "us"
Option "XkbVariant" "basic"
''
];
};
};
}
Mara
This also has Yubikey inputs not get processed into Colemak so that Yubikey OTPs still work as expected. Keep in mind that a Yubikey in this mode pretends to be a keyboard, so without this configuration the OTP will be processed into Colemak. The Yubico verification service will not be able to understand OTPs that are typed out in Colemak.
Then we can turn the identifier and product values into options with mkOption and string interpolation:
# ...
cadey.colemak = {
enable = mkEnableOption "Enables Colemak for the default X config";
ignore = {
identifier = mkOption {
type = types.str;
description = "Keyboard input identifier to send raw keycodes for";
default = "moonlander";
};
product = mkOption {
type = types.str;
description = "Keyboard input product to send raw keycodes for";
default = "Moonlander";
};
};
};
# ...
''
Identifier "${config.cadey.colemak.ignore.identifier}"
MatchIsKeyboard "on"
MatchProduct "${config.cadey.colemak.ignore.product}"
Option "XkbLayout" "us"
''
# ...
Adding this to the default load path and enabling it with cadey.colemak.enable = true;
in my tower's configuration.nix
This section was made possible thanks to help from Graham Christensen who seems to be in search of a job. If you are wanting someone on your team that is kind and more than willing to help make your team flourish, I highly suggest looking into putting him in your hiring pipeline. See here for contact information.
Oryx is the configurator that ZSA created to allow people to create keymaps without needing to compile your own firmware or install the QMK toolchain.
Mara
QMK is the name of the firmware that the Moonlander (and a lot of other custom/split mechanical keyboards) use. It works on AVR and Arm processors.
For most people, Oryx should be sufficient. I actually started my keymap using Oryx and sorta outgrew it as I learned more about QMK. It would be nice if Oryx added leader key support, however this is more of an advanced feature so I understand why it doesn't have that.
This keyboard isn't flawless, but it gets so many things right that this is mostly petty bickering at this point. I had to look hard to find these.
I would have liked having another thumb key for things like layer toggling. I can make do with what I have, but another key would have been nice. Maybe add a 1u key under the red shaped key?
At the point I ordered the Moonlander, I was unable to order a black keyboard with white keycaps. I am told that ZSA will be selling keycap sets as early as next year. When that happens I will be sure to order a white one so that I can have an orca vibe.
ZSA ships with UPS. Normally UPS is fine for me, but the driver that was slated to deliver it one day just didn't deliver it. I was able to get the keyboard eventually though. Contrary to their claims, the UPS website does NOT update instantly and is NOT the most up to date source of information about your package.
The cables aren't braided. I would have liked braided cables.
Like I said, these are really minor things, but it's all I can really come up with as far as downsides go.
Overall this keyboard is amazing. I would really suggest it to anyone that wants to be able to have control over their main tool and craft it towards their desires instead of making do with what some product manager somewhere decided what keys should do what. It's expensive at USD$350, but for the right kind of person this will be worth every penny. Your mileage may vary, but I like it.
Permalink - Posted on 2020-10-31 00:00
It's been a while since I had the last update for Trisiel. In that time I have gotten a lot done. As the title mentions I have completely rewritten Trisiel's entire stack in Rust. Part of the reason was for increased speed and the other part was to get better at Rust. I also wanted to experiment with running Rust in production and this has been an excellent way to do that.
Trisiel is going to have a few major parts:
api.trisiel.com
)run.trisiel.dev
)panel.trisiel.com
)trisiel
docs.trisiel
)These parts will work together to implement a functions as a service platform.
Mara
The executor is on its own domain to prevent problems like this GitHub Pages vulnerability from 2013. It is on a
.lgbt
domain because LGBT rights are human rights.
I have also set up a landing page at trisiel.com and a twitter account at @trisielcloud. Right now these are placeholders. I wanted to register the domains before they were taken by anyone else.
My previous attempt at Trisiel had more of a four tier webapp setup. The overall stack looked something like this:
In simple testing, this works amazingly. The API server will send execution requests to the executors and everything will usually work out. However, the message queue I used was very "fire and forget" and had difficulties with multiple executors set up to listen on the queue. Additionally, the added indirection of needing to send the data around twice means that it would have difficulties scaling globally due to ingress and egress data costs. This model is solid and probably would have worked with some compression or other improvements like that, but overall I was not happy with it and decided to scrap it while I was porting the executor component to Rust. If you want to read the source code of this iteration of Trisiel, take a look here.
The new architecture of Trisiel looks something like this:
The main change here is the fact that the executor listens over HTTPS, avoiding a lot of the overhead involved in running this on a message queue. It's also much simpler to implement and allows me to reuse a vast majority of the boilerplate that I developed for the Trisiel API server.
This new version of Trisiel is also built on top of Wasmer. Wasmer is a seriously fantastic library for this and getting up and running was absolutely trivial, even though I knew very little Rust when I was writing pa'i. I cannot recommend it enough if you ever want to execute WebAssembly on a server.
At this point, I can create new functions, upload them to the API server and then trigger them to be executed. The output of those functions is not returned to the user at this point. I am working on ways to implement that. There is also very little accounting for what resources and system calls are used, however it does keep track of execution time. The executor also needs to have the request body of the client be wired to the standard in of the underlying module, which will enable me to parse CGI replies from WebAssembly functions. This will allow you to host HTTP endpoints on Trisiel using the same code that powers this and this.
I also need to go in and completely refactor the olin crate and make the APIs much more ergonomic, not to mention make the HTTP client actually work again.
Then comes the documentation. Oh god there will be so much documentation. I will be drowning in documentation by the end of this.
I need to write the panel and command line tool for Trisiel. I want to write the panel in Elm and the command line tool in Rust.
There is basically zero validation for anything submitted to the Trisiel API. I will need to write validation in order to make it safer.
I may also explore enabling support for WASI in the future, but as I have stated before I do not believe that WASI works very well for the futuristic plan-9 inspired model I want to use on Trisiel.
Right now the executor shells out to pa'i, but I want to embed pa'i into the executor binary so there are fewer moving parts involved.
I also need to figure out what I should do with this project in general. It feels like it is close to being productizable, but I am in a very bad stage of my life to be able to jump in headfirst and build a company around this. Visa limitations also don't help here.
Rocket is an absolutely fantastic web framework and I
cannot recommend it enough. I am able to save so much time with Rocket and its
slightly magic use of proc-macros. For an example, here is the entire source
code of the /whoami
route in the Trisiel API:
#[get("/whoami")]
#[instrument]
pub fn whoami(user: models::User) -> Json<models::User> {
Json(user)
}
The FromRequest
instance I have on my database user model allows me to inject
the user associated with an API token purely based on the (validated against the
database) claims associated with the JSON Web Token that the user uses for
authentication. This then allows me to make API routes protected by simply
putting the user model as an input to the handler function. It's magic and I
love it.
Postgres lets you use triggers to automatically update updated_at
fields for
free. You just need a function that looks like this:
CREATE OR REPLACE FUNCTION trigger_set_timestamp()
RETURNS TRIGGER AS $$
BEGIN
NEW.updated_at = NOW();
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
And then you can make triggers for your tables like this:
CREATE TRIGGER set_timestamp_users
BEFORE UPDATE ON users
FOR EACH ROW
EXECUTE PROCEDURE trigger_set_timestamp();
Every table in Trisiel uses this in order to make programming against the database easier.
The symbol/number layer on my Moonlander has been so good. It looks something like this:
And it makes using programming sigils so much easier. I don't have to stray
far from the homerow to hit the most common ones. The only one that I still have
to reach for is _
, but I think I will bind that to the blank key under the ]
key.
The best programming music is lofi hip hop radio - beats to study/relax to. Second best is Animal Crossing music. They both have this upbeat quality that makes the ideas melt into code and flow out of your hands.
Overall I'd say this is pretty good for a week of hacking while learning a new keyboard layout. I will do more in the future. I have plans. To read through the (admittedly kinda hacky/awful) code I've written this week, check out this git repo. If you have any feedback, please contact me. I will be happy to answer any questions.
As far as signups go, I am not accepting any signups at the moment. This is pre-alpha software. The abuse story will need to be figured out, but I am fairly sure it will end up being some kind of "pay or you can only run the precompiled example code in the documentation" with some kind of application process for the "free tier" of Trisiel. Of course, this is all theoretical and hinges on Trisiel actually being productizable; so who knows?
Be well.
Permalink - Posted on 2020-10-29 00:00
I've always wanted to make my own compiler. Compilers are an integral part of
my day to day job and I use the fruits of them constantly. A while ago while I
was browsing through the TempleOS source code I found
MiniCompiler.HC in the ::/Demos/Lectures
folder and I was a
bit blown away. It implements a two phase compiler from simple math expressions
to AMD64 bytecode (complete with bit-banging it to an array that the code later
jumps to) and has a lot to teach about how compilers work. For those of you that
don't have a TempleOS VM handy, here is a video of MiniCompiler.HC in action:
You put in a math expression, the compiler builds it and then spits out a bunch of assembly and runs it to return the result. In this series we are going to be creating an implementation of this compiler that targets WebAssembly. This compiler will be written in Rust and will use only the standard library for everything but the final bytecode compilation and execution phase. There is a lot going on here, so I expect this to be at least a three part series. The source code will be in Xe/minicompiler in case you want to read it in detail. Follow along and let's learn some Rust on the way!
Mara
Compilers for languages like C are built on top of the fundamentals here, but they are much more complicated.
This language uses normal infix math expressions on whole numbers. Here are a few examples:
2 + 2
420 * 69
(34 + 23) / 38 - 42
(((34 + 21) / 5) - 12) * 348
Ideally we should be able to nest the parentheses as deep as we want without any issues.
Looking at these values we can notice a few patterns that will make parsing this a lot easier:
Let's turn this description into Rust code:
Make a new project called minicompiler
with a command that looks something
like this:
$ cargo new minicompiler
This will create a folder called minicompiler
and a file called src/main.rs
.
Open that file in your editor and copy the following into it:
// src/main.rs
/// Mathematical operations that our compiler can do.
#[derive(Debug, Eq, PartialEq)]
enum Op {
Mul,
Div,
Add,
Sub,
}
/// All of the possible tokens for the compiler, this limits the compiler
/// to simple math expressions.
#[derive(Debug, Eq, PartialEq)]
enum Token {
EOF,
Number(i32),
Operation(Op),
LeftParen,
RightParen,
}
Mara
In compilers, "tokens" refer to the individual parts of the language you are working with. In this case every token represents every possible part of a program.
And then let's start a function that can turn a program string into a bunch of tokens:
// src/main.rs
fn lex(input: &str) -> Vec<Token> {
todo!("implement this");
}
Mara
Wait, what do you do about bad input such as things that are not math expressions? Shouldn't this function be able to fail?
You're right! Let's make a little error type that represents bad input. For
creativity's sake let's call it BadInput
:
// src/main.rs
use std::error::Error;
use std::fmt;
/// The error that gets returned on bad input. This only tells the user that it's
/// wrong because debug information is out of scope here. Sorry.
#[derive(Debug, Eq, PartialEq)]
struct BadInput;
// Errors need to be displayable.
impl fmt::Display for BadInput {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "something in your input is bad, good luck")
}
}
// The default Error implementation will do here.
impl Error for BadInput {}
And then let's adjust the type of lex()
to compensate for this:
// src/main.rs
fn lex(input: &str) -> Result<Vec<Token>, BadInput> {
todo!("implement this");
}
So now that we have the function type we want, let's start implementing lex()
by setting up the result and a loop over the characters in the input string:
// src/main.rs
fn lex(input: &str) -> Result<Vec<Token>, BadInput> {
let mut result: Vec<Token> = Vec::new();
for character in input.chars() {
todo!("implement this");
}
Ok(result)
}
Looking at the examples from earlier we can start writing some boilerplate to turn characters into tokens:
// src/main.rs
// ...
for character in input.chars() {
match character {
// Skip whitespace
' ' => continue,
// Ending characters
';' | '\n' => {
result.push(Token::EOF);
break;
}
// Math operations
'*' => result.push(Token::Operation(Op::Mul)),
'/' => result.push(Token::Operation(Op::Div)),
'+' => result.push(Token::Operation(Op::Add)),
'-' => result.push(Token::Operation(Op::Sub)),
// Parentheses
'(' => result.push(Token::LeftParen),
')' => result.push(Token::RightParen),
// Numbers
'0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' => {
todo!("implement number parsing")
}
// Everything else is bad input
_ => return Err(BadInput),
}
}
// ...
Mara
Ugh, you're writing
Token::
andOp::
a lot. Is there a way to simplify that?
Yes! enum variants can be shortened to their names with a use
statement like
this:
// src/main.rs
// ...
use Op::*;
use Token::*;
match character {
// ...
// Math operations
'*' => result.push(Operation(Mul)),
'/' => result.push(Operation(Div)),
'+' => result.push(Operation(Add)),
'-' => result.push(Operation(Sub)),
// Parentheses
'(' => result.push(LeftParen),
')' => result.push(RightParen),
// ...
}
// ...
Which looks a lot better.
Mara
You can use the
use
statement just about anywhere in your program. However to keep things flowing nicer, theuse
statement is right next to where it is needed in these examples.
Now we can get into the fun that is parsing numbers. When he wrote MiniCompiler, Terry Davis used an approach that is something like this (spacing added for readability):
case '0'...'9':
i = 0;
do {
i = i * 10 + *src - '0';
src++;
} while ('0' <= *src <= '9');
*num=i;
This sets an intermediate variable i
to 0 and then consumes characters from
the input string as long as they are between '0'
and '9'
. As a neat side
effect of the numbers being input in base 10, you can conceptualize 40
as (4 * 10) + 2
. So it multiplies the old digit by 10 and then adds the new digit to
the resulting number. Our setup doesn't let us get that fancy as easily, however
we can emulate it with a bit of stack manipulation according to these rules:
result
is empty, push this number to result and continue lexing the
programresult
and save it as last
last
is a number, multiply that number by 10 and add the current number
to itresult
and push the current number to
result
as wellTranslating these rules to Rust, we get this:
// src/main.rs
// ...
// Numbers
'0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' => {
let num: i32 = (character as u8 - '0' as u8) as i32;
if result.len() == 0 {
result.push(Number(num));
continue;
}
let last = result.pop().unwrap();
match last {
Number(i) => {
result.push(Number((i * 10) + num));
}
_ => {
result.push(last);
result.push(Number(num));
}
}
}
// ...
Mara
This is not the most robust number parsing code in the world, however it will suffice for now. Extra credit if you can identify the edge cases!
This should cover the tokens for the language. Let's write some tests to be sure everything is working the way we think it is!
Rust has a robust testing
framework built into the
standard library. We can use it here to make sure we are generating tokens
correctly. Let's add the following to the bottom of main.rs
:
#[cfg(test)] // tells the compiler to only build this code when tests are being run
mod tests {
use super::{Op::*, Token::*, *};
// registers the following function as a test function
#[test]
fn basic_lexing() {
assert!(lex("420 + 69").is_ok());
assert!(lex("tacos are tasty").is_err());
assert_eq!(
lex("420 + 69"),
Ok(vec![Number(420), Operation(Add), Number(69)])
);
assert_eq!(
lex("(30 + 560) / 4"),
Ok(vec![
LeftParen,
Number(30),
Operation(Add),
Number(560),
RightParen,
Operation(Div),
Number(4)
])
);
}
}
This test can and probably should be expanded on, but when we run cargo test
:
$ cargo test
Compiling minicompiler v0.1.0 (/home/cadey/code/Xe/minicompiler)
Finished test [unoptimized + debuginfo] target(s) in 0.22s
Running target/debug/deps/minicompiler-03cad314858b0419
running 1 test
test tests::basic_lexing ... ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
And hey presto! We verified that all of the parsing is working correctly. Those test cases should be sufficient to cover all of the functionality of the language.
This is it for part 1. We covered a lot today. Next time we are going to run a validation pass on the program, convert the infix expressions to reverse polish notation and then also get started on compiling that to WebAssembly. This has been fun so far and I hope you were able to learn from it.
Special thanks to the following people for reviewing this post: