A GitHub Action for exclusive control.
- avoid running multiple jobs concurrently across workflows
on:
push:
branches:
- main
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- uses: shogo82148/actions-mutex@v1
with:
key: deploy
- run: ': some jobs that can not run concurrently'The name of the critical section. The default is "lock".
A GitHub Token. It must have a write access to the repository.
The default is "${{ github.token }}"
A repository for locking. The default is the repository that the workflow runs on.
Prefix of branch names for locking. The default is "actions-mutex-lock/"
As you known, Git rejects non-fast-forward updates. The action uses it for locking.
The action tries to push a commit that contains a random string. If the pushing succeeds, it means that no concurrent jobs run.
$ echo "$RANDOM" > lock.txt
$ git add lock.txt
$ git commit -m 'add lock files'
$ git push origin HEAD:actions-mutex-lock/lock
To https://github.com/shogo82148/actions-mutex
* [new branch] HEAD -> actions-mutex-lock/lock
If the pushing fails, it means that a concurrent job is now running. The action will retry to push after some wait.
$ echo "$RANDOM" > lock.txt
$ git add lock.txt
$ git commit -m 'add lock files'
$ git push origin HEAD:actions-mutex-lock/lock
To https://github.com/shogo82148/actions-mutex
! [rejected] HEAD -> actions-mutex-lock/lock (fetch first)
error: failed to push some refs to 'https://github.com/shogo82148/actions-mutex'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.