👷(ci) check the load-test tooling: swarm, canary, k6 and dashboards

Add missing jobs to run the tests in swarm and canary projects. For k6
the project is inspected using k6 docker image and for the grafana
dashboard we check if the generated dashboard equals the one existing.

.github/workflows/loadtest.yml

@@ -0,0 +1,113 @@
+name: Load Test Tooling Workflow
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - "*"
+
+permissions:
+  contents: read
+
+# The load-test tooling of src/loadtest (see documentation/load-testing.md).
+# swarm and canary are standalone TypeScript packages, each with its own
+# package.json and yarn.lock, like src/yhub-server; k6 runs plain scripts and
+# the dashboards are generated by a python script.
+jobs:
+  lint-and-test-loadtest:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        package:
+          - swarm
+          - canary
+    defaults:
+      run:
+        working-directory: src/loadtest/${{ matrix.package }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: "22.x"
+          cache: yarn
+          cache-dependency-path: src/loadtest/${{ matrix.package }}/yarn.lock
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+
+      - name: Lint
+        run: yarn lint
+
+      - name: Typecheck
+        run: yarn typecheck
+
+      # the image compiles with tsconfig.build.json (rootDir ./src, emits),
+      # which can fail where the typecheck passes
+      - name: Build
+        run: yarn build
+
+      # the canary specs drive a real Chromium against a page served
+      # in-process: install the one matching the playwright package
+      - name: Install Chromium
+        if: matrix.package == 'canary'
+        run: yarn playwright install --with-deps --only-shell chromium
+
+      - name: Test
+        run: yarn test
+
+  check-k6:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
+
+      # `k6 inspect` runs the init context of each scenario (imports, options,
+      # the manifest checks) without sending a request. The scripts refuse to
+      # load without a manifest holding a session: give them a dummy one.
+      - name: Inspect the scenarios
+        run: |
+          echo '{"cookie_name": "sessionid", "sessions": [{"session_key": "x", "editable_documents": [], "readonly_documents": []}]}' \
+            > "$RUNNER_TEMP/manifest.json"
+          for scenario in src/loadtest/k6/scenarios/*.js; do
+            echo "::group::$scenario"
+            docker run --rm \
+              -v "$PWD/src/loadtest/k6:/k6:ro" \
+              -v "$RUNNER_TEMP/manifest.json:/manifest.json:ro" \
+              -w /k6 grafana/k6:2.3.0 inspect "scenarios/$(basename "$scenario")"
+            echo "::endgroup::"
+          done
+
+  check-dashboards:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
+
+      # the docs-loadtest-* boards are generated: the committed JSON must be
+      # what generate.py writes (django.json is a community board, not
+      # generated, and is left out of the comparison)
+      - name: Check the dashboards are up to date
+        run: |
+          mkdir -p "$RUNNER_TEMP/dashboards"
+          python3 src/loadtest/dashboards/generate.py "$RUNNER_TEMP/dashboards"
+          status=0
+          for generated in "$RUNNER_TEMP"/dashboards/*.json; do
+            committed="src/loadtest/dashboards/$(basename "$generated")"
+            if ! diff -u "$committed" "$generated"; then
+              echo "::error file=$committed::out of date, run: python3 src/loadtest/dashboards/generate.py src/loadtest/dashboards"
+              status=1
+            fi
+          done
+          exit $status

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to
 ### Added
 
 - 👷(ci) lint, typecheck, build and test the collaboration server (yhub)
+- 👷(ci) check the load-test tooling: swarm, canary, k6 and dashboards
 - ✨(backend) add mention endpoint with cooldown-limited email 
   notification #2447
 - 🚩(setting) add feature flag on Duplicate with Children #2721