From 020c1e77489b772f854bb3288b9c8d2818a6bf9d Mon Sep 17 00:00:00 2001 From: EuAndreh Date: Fri, 18 Apr 2025 02:17:12 -0300 Subject: git mv src/content/* src/content/en/ --- .../en/tils/2020/11/12/diy-nix-bash-ci.adoc | 63 ++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 src/content/en/tils/2020/11/12/diy-nix-bash-ci.adoc (limited to 'src/content/en/tils/2020/11/12/diy-nix-bash-ci.adoc') diff --git a/src/content/en/tils/2020/11/12/diy-nix-bash-ci.adoc b/src/content/en/tils/2020/11/12/diy-nix-bash-ci.adoc new file mode 100644 index 0000000..97ace30 --- /dev/null +++ b/src/content/en/tils/2020/11/12/diy-nix-bash-ci.adoc @@ -0,0 +1,63 @@ += DIY bare bones CI server with Bash and Nix +:categories: ci +:sort: 2 + +:post-receive: https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks +:example-project: https://euandreh.xyz/remembering/ci.html + +With a server with Nix installed (no need for NixOS), you can leverage its build +isolation for running CI jobs by adding a {post-receive}[post-receive] Git hook +to the server. + +In most of my project I like to keep a `test` attribute which runs the test with +`nix-build -A test`. This way, a post-receive hook could look like: + +[source,sh] +---- +#!/usr/bin/env bash +set -Eeuo pipefail +set -x + +LOGS_DIR="/data/static/ci-logs/libedn" +mkdir -p "$LOGS_DIR" +LOGFILE="${LOGS_DIR}/$(date -Is)-$(git rev-parse master).log" +exec &> >(tee -a "${LOGFILE}") + +unset GIT_DIR +CLONE="$(mktemp -d)" +git clone . "$CLONE" +pushd "$CLONE" + +finish() { + printf "\n\n>>> exit status was %s\n" "$?" +} +trap finish EXIT + +nix-build -A test +---- + +We initially (lines #5 to #8) create a log file, named after _when_ the run is +running and for _which_ commit it is running for. The `exec` and `tee` combo +allows the output of the script to go both to `stdout` _and_ the log file. This +makes the logs output show up when you do a `git push`. + +Lines #10 to #13 create a fresh clone of the repository and line #20 runs the +test command. + +After using a similar post-receive hook for a while, I now even generate a +simple HTML file to make the logs available ({example-project}[example project]) +through the browser. + +== Upsides + +No vendor lock-in, as all you need is a server with Nix installed. + +And if you pin the Nixpkgs version you're using, this very simple setup yields +extremely sandboxed runs on a very hermetic environment. + +== Downsides + +Besides the many missing shiny features of this very simplistic CI, `nix-build` +can be very resource intensive. Specifically, it consumes too much memory. So +if it has to download too many things, or the build closure gets too big, the +server might very well run out of memory. -- cgit v1.2.3