Fix push-images workflow failing due to low disk space. (#1497)

.github/actions/mount-scratch-disk/action.yml

@@ -0,0 +1,37 @@
+# Copyright 2024 The Cross-Media Measurement Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Mount scratch disk
+description: >
+  Create a bind mount for scratch disk space.
+  
+  Note that this is a hack to utilize the currently largely unused space at
+  /mnt. This is relying on undocumented behavior that may change.
+inputs: 
+  mount-path:
+    description: Path to mount scratch disk
+    required: true
+runs: 
+  using: composite
+  steps:
+  - shell: bash
+    env:
+      MOUNT_PATH: ${{ inputs.mount-path }}
+    run: |
+      dir_name="$(printf '%s' "$MOUNT_PATH" | sha256sum | cut -d ' ' -f 1)"
+      source_path="/mnt/${dir_name}"
+      mkdir -p "$MOUNT_PATH"
+      sudo mkdir -p "${source_path}"
+      sudo chown 'runner:runner' "${source_path}"
+      sudo mount --bind "${source_path}" "$MOUNT_PATH"

.github/workflows/build-test.yml

@@ -89,18 +89,12 @@ jobs:
           repo_cache_path="$(bazelisk info repository_cache)"
           echo "repo-cache-path=${repo_cache_path}" >> $GITHUB_OUTPUT
 
-      # This is a hack to utilize the undocumented relatively large empty
-      # scratch disk mounted at /mnt. It's currently needed to work around
-      # bazel-contrib/rules_oci#439 as that's what is pushing our usage over the
-      # limit. The alternative is to use a runner with more disk space. 
+      # Hack to work around disk space consumed by bazel-contrib/rules_oci#439.
+      # The alternative is to use a runner with more disk space.
       - name: Mount scratch disk
-        env:
-          BAZEL_CACHE_PATH: ${{ steps.get-cache-params.outputs.cache-path }}
-        run: |
-          mkdir -p "$BAZEL_CACHE_PATH"
-          sudo mkdir -p /mnt/bazel-cache
-          sudo chown 'runner:runner' /mnt/bazel-cache
-          sudo mount --bind /mnt/bazel-cache "$BAZEL_CACHE_PATH"
+        uses: ./.github/actions/mount-scratch-disk
+        with:
+          mount-path: ${{ steps.get-cache-params.outputs.cache-path }}
 
       - name: Restore repository cache
         uses: actions/cache/restore@v4

.github/workflows/push-images.yml

@@ -29,10 +29,11 @@ jobs:
       image-tag: ${{ steps.get-image-tag.outputs.image-tag }}
     permissions:
       id-token: write
+      packages: write
     env:
       CONTAINER_REGISTRY: ghcr.io
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: ./.github/actions/free-disk-space
 
@@ -72,6 +73,16 @@ jobs:
           repo_cache_path="$(bazelisk info repository_cache)"
           echo "repo-cache-path=${repo_cache_path}" >> $GITHUB_OUTPUT
 
+          cache_path="$(bazelisk info output_base)"
+          echo "cache-path=${cache_path}" >> $GITHUB_OUTPUT
+          
+      # Hack to work around disk space consumed by bazel-contrib/rules_oci#439.
+      # The alternative is to use a runner with more disk space.
+      - name: Mount scratch disk
+        uses: ./.github/actions/mount-scratch-disk
+        with:
+          mount-path: ${{ steps.get-cache-params.outputs.cache-path }}
+
       - name: Restore repository cache
         uses: actions/cache/restore@v4
         with: