Add Bazel remote cache parity check (#7077)

.github/workflows/bazel_cache_parity.yml

@@ -0,0 +1,59 @@
+name: Bazel Cache Parity
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '17 11 * * *'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+permissions:
+  contents: read
+
+jobs:
+  warm-cache:
+    runs-on: [self-hosted, bazel]
+
+    steps:
+      - name: Clean workspace
+        run: |
+          git sparse-checkout disable 2>/dev/null || true
+          git config --local core.sparseCheckout false 2>/dev/null || true
+          git config --local --unset extensions.worktreeConfig 2>/dev/null || true
+          rm -f .git/info/sparse-checkout .git/config.worktree 2>/dev/null || true
+      - name: Checkout repository
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+          lfs: false
+      - name: Ensure Bazel installed
+        run: ./ci/github_actions/ensure_bazel_installed.sh
+      - name: Warm remote cache
+        run: ./scripts/check_bazel_remote_cache_parity.sh warm
+
+  verify-cache:
+    needs: warm-cache
+    runs-on: [self-hosted, bazel]
+    strategy:
+      fail-fast: false
+      matrix:
+        probe: [a, b]
+
+    steps:
+      - name: Clean workspace
+        run: |
+          git sparse-checkout disable 2>/dev/null || true
+          git config --local core.sparseCheckout false 2>/dev/null || true
+          git config --local --unset extensions.worktreeConfig 2>/dev/null || true
+          rm -f .git/info/sparse-checkout .git/config.worktree 2>/dev/null || true
+      - name: Checkout repository
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+          lfs: false
+      - name: Ensure Bazel installed
+        run: ./ci/github_actions/ensure_bazel_installed.sh
+      - name: Verify remote cache parity
+        run: ./scripts/check_bazel_remote_cache_parity.sh verify

scripts/check_bazel_remote_cache_parity.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+usage() {
+    echo "Usage: $0 <warm|verify> [bazel targets...]"
+    echo
+    echo "warm:   build targets normally so local results can upload to the remote cache"
+    echo "verify: require all target actions to be available from remote cache"
+}
+
+if [ "$#" -lt 1 ]; then
+    usage
+    exit 2
+fi
+
+mode="$1"
+shift
+
+case "$mode" in
+    warm | verify)
+        ;;
+    *)
+        usage
+        exit 2
+        ;;
+esac
+
+targets=("$@")
+if [ "${#targets[@]}" -eq 0 ]; then
+    targets=(
+        "//src/main/cpp/net/eagle0/shardok/library:engine"
+        "//src/main/scala/net/eagle0/eagle:eagle_server"
+    )
+fi
+
+tmp_root="${RUNNER_TEMP:-/private/tmp}"
+run_id="${GITHUB_RUN_ID:-local}-$$"
+output_base="${tmp_root%/}/eagle0-cache-parity-${mode}-${run_id}"
+
+echo "Mode: $mode"
+echo "Output base: $output_base"
+echo "Targets:"
+printf '  %s\n' "${targets[@]}"
+
+bazel_args=(
+    "--output_base=$output_base"
+    "build"
+    "--remote_download_all"
+)
+
+if [ "$mode" = "verify" ]; then
+    bazel_args+=(
+        "--remote_upload_local_results=false"
+        "--experimental_remote_require_cached"
+        "--disk_cache="
+    )
+fi
+
+bazel "${bazel_args[@]}" "${targets[@]}"