From 21c82dcd623a584b2f716f70eeec1db0326e46db Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 30 Aug 2023 15:51:13 -0400 Subject: ci: allow branch selection through "vars" When we added config to skip CI for certain branches in e76eec3554 (ci: allow per-branch config for GitHub Actions, 2020-05-07), there wasn't any way to avoid spinning up a VM just to check the config. From the developer's perspective this isn't too bad, as the "skipped" branches complete successfully after running the config job (the workflow result is "success" instead of "skipped", but that is a minor lie). But we are still wasting time and GitHub's CPU to spin up a VM just to check the result of a short shell script. At the time there wasn't any way to avoid this. But they've since introduced repo-level variables that should let us do the same thing: https://github.blog/2023-01-10-introducing-required-workflows-and-configuration-variables-to-github-actions/#configuration-variables This is more efficient, and as a bonus is probably less confusing to configure (the existing system requires sticking your config on a magic ref). See the included docs for how to configure it. The code itself is pretty simple: it checks the variable and skips the config job if appropriate (and everything else depends on the config job already). There are two slight inaccuracies here: - we don't insist on branches, so this likewise applies to tag names or other refs. I think in practice this is OK, and keeping the code (and docs) short is more important than trying to be more exact. We are targeting developers of git.git and their limited workflows. - the match is done as a substring (so if you want to run CI for "foobar", then branch "foo" will accidentally match). Again, this should be OK in practice, as anybody who uses this is likely to only specify a handful of well-known names. If we want to be more exact, we can have the code check for adjoining spaces. Or even move to a more general CI_CONFIG variable formatted as JSON. I went with this scheme for the sake of simplicity. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- ci/config/README | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 ci/config/README (limited to 'ci') diff --git a/ci/config/README b/ci/config/README new file mode 100644 index 0000000000..8de3a04e32 --- /dev/null +++ b/ci/config/README @@ -0,0 +1,14 @@ +You can configure some aspects of the GitHub Actions-based CI on a +per-repository basis by setting "variables" and "secrets" from with the +GitHub web interface. These can be found at: + + https://github.com//git/settings/secrets/actions + +The following variables can be used: + + - CI_BRANCHES + + By default, CI is run when any branch is pushed. If this variable is + non-empty, then only the branches it lists will run CI. Branch names + should be separated by spaces, and should use their shortened form + (e.g., "main", not "refs/heads/main"). -- cgit v1.2.3 From edf80d23f1e945646a873dc9a4fa6634dd9e8ae8 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 30 Aug 2023 15:51:32 -0400 Subject: ci: deprecate ci/config/allow-ref script Now that we have the CI_BRANCHES mechanism, there is no need for anybody to use the ci/config/allow-ref mechanism. In the long run, we can hopefully remove it and the whole "config" job, as it consumes CPU and adds to the end-to-end latency of the whole workflow. But we don't want to do that immediately, as people need time to migrate until the CI_BRANCHES change has made it into the workflow file of every branch. So let's issue a warning, which will appear in the "annotations" section below the workflow result in GitHub's web interface. And let's remove the sample allow-refs script, as we don't want to encourage anybody to use it. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- ci/config/allow-ref.sample | 27 --------------------------- 1 file changed, 27 deletions(-) delete mode 100755 ci/config/allow-ref.sample (limited to 'ci') diff --git a/ci/config/allow-ref.sample b/ci/config/allow-ref.sample deleted file mode 100755 index af0e076f8a..0000000000 --- a/ci/config/allow-ref.sample +++ /dev/null @@ -1,27 +0,0 @@ -#!/bin/sh -# -# Sample script for enabling/disabling GitHub Actions CI runs on -# particular refs. By default, CI is run for all branches pushed to -# GitHub. You can override this by dropping the ".sample" from the script, -# editing it, committing, and pushing the result to the "ci-config" branch of -# your repository: -# -# git checkout -b ci-config -# cp allow-ref.sample allow-ref -# $EDITOR allow-ref -# git add allow-ref -# git commit -am "implement my ci preferences" -# git push -# -# This script will then be run when any refs are pushed to that repository. It -# gets the fully qualified refname as the first argument, and should exit with -# success only for refs for which you want to run CI. - -case "$1" in -# allow one-off tests by pushing to "for-ci" or "for-ci/mybranch" -refs/heads/for-ci*) true ;; -# always build your integration branch -refs/heads/my-integration-branch) true ;; -# don't build any other branches or tags -*) false ;; -esac -- cgit v1.2.3