From c81c2d6eec3e6101080168a3514b94876e8b640c Mon Sep 17 00:00:00 2001
From: Thomas Ferreira de Lima <github@tlima.me>
Date: Mon, 29 May 2023 17:36:20 -0400
Subject: [PATCH] autodelete github Action caches after PR is merged

Caches are very large and must be deleted to prioritize main branch's caches.
---
 .github/workflows/cache-maintenance.yml | 35 +++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 .github/workflows/cache-maintenance.yml

diff --git a/.github/workflows/cache-maintenance.yml b/.github/workflows/cache-maintenance.yml
new file mode 100644
index 000000000..ec933b1f1
--- /dev/null
+++ b/.github/workflows/cache-maintenance.yml
@@ -0,0 +1,35 @@
+name: cleanup caches by a branch
+# https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#force-deleting-cache-entries
+# Caches are very large and must be deleted to prioritize main branch's caches.
+on:
+  pull_request:
+    types:
+      - closed
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Cleanup
+        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 key"
+          cacheKeysForPR=$(gh actions-cache list -R $REPO -B $BRANCH | cut -f 1 )
+
+          ## Setting this to not fail the workflow while deleting cache keys.
+          set +e
+          echo "Deleting caches..."
+          for cacheKey in $cacheKeysForPR
+          do
+              gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
+          done
+          echo "Done"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
\ No newline at end of file