spread hello world

.github/workflows/ci.yaml

@@ -72,3 +72,55 @@ jobs:
     uses: canonical/data-platform-workflows/.github/workflows/[email protected]
     with:
       charmcraft-snap-channel: latest/candidate  # TODO: remove after charmcraft 3.3 stable release
+
+  collect-integration-tests:
+    name: Collect integration test spread jobs
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Set up environment
+        run: sudo snap install charmcraft --classic --channel latest/candidate
+      - name: Collect spread jobs
+        id: collect-jobs
+        shell: python
+        run: |
+          import json
+          import os
+          import subprocess
+
+          jobs = (
+              subprocess.run(
+                  ["charmcraft", "test", "--list", "github-ci"], capture_output=True, check=True, text=True
+              )
+              .stdout.strip()
+              .split("\n")
+          )
+          output = f"jobs={json.dumps(jobs)}"
+          print(output)
+          with open(os.environ["GITHUB_OUTPUT"], "a") as file:
+              file.write(output)
+    outputs:
+      jobs: ${{ steps.collect-jobs.outputs.jobs }}
+
+  integration-test:
+    strategy:
+      fail-fast: false
+      matrix:
+        spread-job: ${{ fromJSON(needs.collect-integration-tests.outputs.jobs) }}
+    name: Spread ${{ matrix.spread-job }}
+    needs:
+      - collect-integration-tests
+    runs-on: ubuntu-latest
+    timeout-minutes: 200 # TODO
+    steps:
+      - name: Checkout
+        timeout-minutes: 3
+        uses: actions/checkout@v4
+      - name: Set up environment
+        timeout-minutes: 5
+        run: sudo snap install charmcraft --classic --channel latest/candidate
+      - name: Run spread job
+        timeout-minutes: 120
+        run: charmcraft test '${{ matrix.spread-job }}'

spread.yaml

@@ -0,0 +1,28 @@
+project: mysql-router-k8s-operator
+
+backends:
+  github-ci:
+    type: adhoc
+    # Only run on CI
+    manual: true
+    # HACK: spread requires runners to be accessible via SSH
+    # Configure local sshd & instruct spread to connect to the same machine spread is running on
+    # (spread cannot provision GitHub Actions runners, so we provision a GitHub Actions runner for
+    # each spread job & select a single job when running spread)
+    # Derived from https://github.com/jnsgruk/zinc-k8s-operator/blob/e2371961e0c18a21fc7bdbd0a7046a3550ce8538/spread.yaml#L47
+    allocate: |
+      sudo tee /etc/ssh/sshd_config.d/10-spread-github-ci.conf << 'EOF'
+      PasswordAuthentication yes
+      PermitEmptyPasswords yes
+      EOF
+
+      ADDRESS localhost
+    systems:
+      - ubuntu-latest:
+          username: runner
+
+suites:
+  tests/spread/:
+    summary: Spread tests
+
+path: /remote/path

tests/spread/foo/task.yaml

@@ -0,0 +1,4 @@
+summary: foo
+execute: |
+  echo "Hello world!"
+  exit 1