feat: use GitHub Actions cache to persist the CernVM-FS cache

.github/workflows/cache.yml

@@ -0,0 +1,24 @@
+name: cache
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron:  '44 4 * * *'
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-24.04]
+    steps:
+    - uses: actions/checkout@v4
+    - run: mkdir -p ${{ github.workspace }}/.cvmfs
+    - uses: ./
+      with:
+        actions_cache: true
+        cvmfs_cache_base: ${{ github.workspace }}/.cvmfs
+    - name: Test CernVM-FS
+      run: |
+        source /cvmfs/sft.cern.ch/lcg/views/LCG_107/x86_64-ubuntu2404-gcc13-opt/setup.sh
+        root -l -q -b

action.yml

@@ -8,6 +8,10 @@ inputs:
     description: 'Location (directory) of the user-space apt cache.'
     required: false
     default: 'apt_cache'
+  actions_cache:
+    description: 'Enable a GitHub Actions cache for the CernVM cache.'
+    required: false
+    default: 'false'
   cvmfs_alien_cache:
     description: 'If set, use an alien cache at the given location.'
     required: false
@@ -351,6 +355,12 @@ runs:
         key: cvmfs-apt-cache-${{ steps.lsb-release.outputs.id-release }}-${{ steps.lsb-release.outputs.arch }}-${{ hashFiles('action.yml') }}
         path: |
           ${{ inputs.apt_cache }}
+    - uses: actions/cache@v4
+      if: ${{ inputs.actions_cache == 'true' }}
+      with:
+        key: cvmfs-cache-${{ steps.lsb-release.outputs.id-release }}-${{ steps.lsb-release.outputs.arch }}-${{ hashFiles('action.yml') }}
+        path: |
+          ${{ inputs.cvmfs_cache_base }}
     - run: |
         ${{ github.action_path }}/setup-cvmfs.sh
       shell: bash