Problem: `(bufferp "*Warnings*")` always returns `nil` because it expects a
buffer object. Thankfully I wrote a function called `buffer-exists?`, which is a
more DWIM alternative of `bufferp`.
Hopefully now CI should fail!
TL;DR:
- Assert that the path to the init.el exists
- Check *Errors* buffer in case an error is uncaught but logged
- Log a message when Emacs successfully initializes
These were hard-coded as $HOME/BRIEFCASE, which won't work in CI, since CI runs
as the user buildkite-agent-socrates, whose $HOME directory doesn't exist.
TL;DR:
- Define runEmacsScript to emacs/default.nix for ci/pipelines/post-receive
- Write script.el to call (load init.el) and catch any errors
- Lint Elisp with gonewest818/elisp-lint
Also nice how Buildkite supports :gnu: emojis!
I wanted Gitea to call Buildkite's pre-receive pipeline and either accept or
reject the incoming code depending on the outcome. The problem is that I can
only *create* builds from Gitea's pre-receive hook.
Now I'm left with two options:
1. run the lint-secrets step in post-receive
2. run `/nix/store/<hash>/git-secrets --scan-history $REPO_PATH` in Gitea
As far as I can tell, I cannot define Gitea hooks in Nix, which is unfortunate;
otherwise, option 2 would appeal more.
I'm doing option one for now.
So it turns out that I was wrong and that .git/config is stateful. Multiple
calls to --add-provider will append the same provider each time...
Instead I'm defining secret-patterns.txt and version-controlling it.
Then:
- dev-side: I'm adding `providers = cat ci/secret-patterns.txt` to .git/config
- ci-side: I'm adding `providers = cat ci/secret-patterns.txt` to .git/config
Unfortunately this is ad-hoc configuration ci-side, which I would like to
avoid. The good news is that my pre-commit hooks and failures from git-secrets
should now align with my CI, since they're both reading from
secret-patterns.txt. One step backwards... two steps forwards?
I'm also `cat .git/config` because I think the Buildkite destroys the
.git/config file for each build, but I want to verify that. If it does, I prefer
that because it seems to share the spirit of the "Destroy Your Darlings" essay.
Problem: my dev machine returns a different value for `git config --get-all
secrets.patterns` than my CI machine... I ran `git-secrets --register-aws` to
get additional coverage, but it's still not the same. I created an issue on the
git-secrets GH repo to get better troubleshooting advice, but I don't need the
logging info. anymore, so I'm removing it.
Somehow `git-secrets --scan-history` is exiting non-zero, when I don't think it
should. Logging some environment information to get a better idea of what's
going on.
After a handful of failed attempts to run lint-secrets.sh due to a missing
`git-secrets` executable on my git server, I decided that now was a good time to
use Nix to define my BuildKite pipelines.
TL;DR:
- Delete ci/scripts directory
- Define ci/pipelines/{briefcase,socrates}.nix
Outside of this repository:
- I logged into my admin account at git.wpcarro.dev and changed my Gitea
post-receive hook to trigger the briefcase pipeline
- I logged into my BuildKite account, deleted my build-briefcase pipeline,
created a new briefcase pipeline that called:
```shell
nix-build -A ci.pipelines.briefcase -o briefcase.yaml
buildkite-agent pipeline upload briefcase.yaml
```
One day I will audit all of my ad-hoc, non-mono-repo activity (like the steps I
listed above) and attempt to fit everything herein... one step at a time,
though!
Adding a fake secret to test to the new CI build step. I'm not sure I expect
this to fail the step because it relies on a pattern that I defined in
.git/config... let's see!
My builds are still failing. This time with...
```
error: getting status of /home/wpcarro/nixpkgs-channels: Permission denied
```
...what confused me was the following:
```shell
$ sudo -u buildkite-agent-socrates stat /home/wpcarro/nixpkgs-channels
permission denied
```
But `ls -al /home/wpcarro | grep nixpkgs-channels` showed `r-w` for all users...
Thankfully @riking on ##tvl told me that I should check the permissions for
/home/wpcarro and /home...
After running `ls -al /home`, I saw `---` for all user... I then reproduced the
error by running:
```shell
$ sudo -u buildkite-agent-socrates stat /home
permission denied
```
Great!
So then I moved nixpkgs-channels to /var/lib/buildkite-agent-socrates. @edef
recommended that I read more about DynamicUser= setting for systemd, which looks
relevant after I took a cursory glance.
I'll also want a more declarative way to manager this, but I'm making small
improvements every day.
For now, I'm supporting two CI pipelines:
- build-socrates
- build-briefcase
Conceptually, build-briefcase should cover what build-socrates does now, but
eventually I would like build-socrates to call `switch-to-configuration` so that
all of my websites, etc. stay fresh.
Unforeseen problem: `buildkite-agent` runs its builds in a separate directory,
so if I want the `nix-build` command to build the newly checked out code, I need
to set <briefcase> to the CWD.
I've encountered a few problems with attempting to support nixos-rebuild:
- the activation step requires `sudo` privileges
- the `buildkite-agent` runs on the same machine, socrates, that is rebuilding
itself. This means that when the activation step runs, it will attempt to
restart `buildkite-agent` when the agent is still working
I'm slowly removing places in my nix code that rely on '<bracket>' notation, so
that I no longer depend on NIX_PATH being set. I still have more work to do.
{covid-uk,sandbox}/default.nix are breaking when I attempt to run my
build-socrates.sh script locally, so I'm temporarily disabling them until I can
get CI working as I expect.
- using `set -euo pipefail` for setting recommended failure-modes
- using `set -x` and `echo "$PATH"` to debug my failing build
Sidenote: I find BuildKite's documentation quite helpful!
