cache-eviction.yaml

name: Cache Eviction

on:
  pull_request:
    types: closed

env:
  GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

jobs:
  evict-mod-cache-closed-pr:
    name: Evict Go Modules Cache for Closed PRs
    runs-on: ubuntu-22.04
    timeout-minutes: 5
    steps:
      - name: Check out code
        uses: actions/checkout@v4
      - name: Cleanup Cache for PR
        # In this step we will delete the cache keys for the PR that was just closed.
        # We use a GitHub CLI extension (https://github.com/actions/gh-actions-cache).
        # The default number of cache keys returned by a list query is 30, but the maximum is 100.
        # It is doubtful that there will be many keys for the given branch, but to be certain
        # we set the limit to the maximum, 100.
        run: |
          gh extension install actions/gh-actions-cache

          REPO=${{ github.repository }}
          BRANCH="refs/pull/${{ github.event.pull_request.number }}/merge"

          echo "Fetching list of cache keys for branch $BRANCH"
          cacheKeysForPR=$(gh actions-cache list -R $REPO -B $BRANCH -L 100 | cut -f 1 )

          ## Setting this to not fail the workflow while deleting cache keys.
          set +e
          echo "Deleting caches..."
          for cacheKey in $cacheKeysForPR
          do
              echo "Deleting cache key $cacheKey"
              gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
          done
          echo "Done"