Rework CI workflow

.github/actionlint.yaml

@@ -0,0 +1,24 @@
+# Copyright 2025 Google LLC
+#
+# 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
+#
+#     https://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.
+
+# Summary: config actionlint (https://github.com/rhysd/actionlint) for certain
+# things we use.
+
+self-hosted-runner:
+  # We don't have self-hosted runners, but we do use some of the "partner"
+  # runner images from https://github.com/actions/partner-runner-images
+  # and some runners that actionlint doesn't currently recognize.
+  labels:
+    - ubuntu-24.04-arm
+    - ubuntu-slim

.github/actions/set-up-bazelisk/action.yaml

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+# Copyright 2025 Google LLC
+#
+# 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
+#
+#     https://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: Set up Bazelisk with caching
+description: Installs Bazelisk and sets up multiple caches for Bazel
+
+# Summary: reusable workflow to install Bazelisk (for Bazel) and set up Bazel
+# caches. It grew out of trouble getting the existing bazel-contrib/setup-bazel
+# action (from the GitHub Marketplace) to work with Netkos' "act".
+
+inputs:
+  debug:
+    description: 'Run with debugging options'
+    type: boolean
+    required: false
+    default: true
+
+permissions:
+  actions: write
+  contents: read
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Read .bazelversion
+      id: read-version
+      shell: bash
+      run: |
+        if [[ ! -f ".bazelversion" ]]; then
+          echo "::error::.bazelversion file not found in repository root."
+          exit 1
+        fi
+        echo "version=$(cat .bazelversion | tr -d ' \n\r')" >> "$GITHUB_OUTPUT"
+
+    - name: Install Bazelisk
+      env:
+        BAZELISK_SHOW_PROGRESS: ${{inputs.debug == 'true'}}
+      shell: bash
+      run: npm install -g @bazel/bazelisk
+
+    - name: Set up cache for Bazelisk
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830  # v4.3.0
+      with:
+        path: ~/.cache/bazelisk
+        key: bazelisk-v1-${{runner.os}}-${{steps.read-version.outputs.version}}
+        restore-keys: bazelisk-v1-${{runner.os}}-
+
+    - name: Set up Bazel repository cache
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830  # v4.3.0
+      with:
+        path: ~/.cache/bazel/repository_cache
+        # yamllint disable-line rule:line-length
+        key: bazel-repo-v1-${{runner.os}}-${{hashFiles('**/WORKSPACE', '**/BUILD', '**/BUILD.tpl', '**/*.bzl')}}
+        restore-keys: bazel-repo-v1-${{runner.os}}-
+
+    - name: Set up Bazel external repositories cache
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830  # v4.3.0
+      with:
+        path: ~/.cache/bazel/output_base/external
+        # yamllint disable-line rule:line-length
+        key: bazel-external-v1-${{runner.os}}-${{hashFiles('**/WORKSPACE', '**/BUILD', '**/BUILD.tpl', '**/*.bzl')}}
+        restore-keys: bazel-external-v1-${{runner.os}}-
+
+    - name: Set up Bazel disk cache
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830  # v4.3.0
+      with:
+        path: ~/.cache/bazel/disk_cache
+        key: bazel-disk-v1-${{runner.os}}-${{github.ref}}-${{github.sha}}
+        restore-keys: bazel-disk-v1-${{runner.os}}-${{github.ref}}-
+
+    - name: Determine the number of processors we can use
+      shell: bash
+      run: |
+        if [[ "${{startsWith(runner.os, 'win')}}" == "true" ]]; then
+          echo "num_cpus=${NUMBER_OF_PROCESSORS}" >> "$GITHUB_ENV"
+        else
+          echo "num_cpus=$(getconf _NPROCESSORS_ONLN)" >> "$GITHUB_ENV"
+        fi
+
+    - name: Make additions to .bazelrc for the cache configuration
+      shell: bash
+      run: |
+        {
+        echo "startup --output_base=~/.cache/bazel/output_base"
+        echo "build --disk_cache=~/.cache/bazel/disk_cache"
+        echo "build --repository_cache=~/.cache/bazel/repository_cache"
+        echo "build --jobs=${{env.num_cpus}}"
+        } >> .bazelrc
+
+    - name: Print configuration information
+      if: inputs.debug == 'true'
+      shell: bash
+      run: |
+        bazelisk --version
+        echo "::group::Contents of .bazelversion"
+        cat .bazelversion
+        echo "::endgroup::"
+        echo "::group::Contents of .bazelrc"
+        cat .bazelrc
+        echo "::endgroup::"
+        echo "::group::GitHub context"
+        echo "The job_id is: $GITHUB_JOB"
+        echo "The id of this action is: $GITHUB_ACTION"
+        echo "The run id is: $GITHUB_RUN_ID"
+        echo "GitHub SHA: $GITHUB_SHA"
+        echo "::endgroup::"