CI/CD Deployment for screenly/balena-prometheus-exporter

The screenly/balena-prometheus-exporter project currently does not have a CI/CD pipeline set up. This section outlines the relevant next steps for implementing a CI/CD deployment strategy.

Next Steps for CI/CD Setup

1. Choose a CI/CD Tool: Select an appropriate CI/CD tool based on your requirements. Popular choices include GitHub Actions, GitLab CI, CircleCI, Jenkins, or Travis CI.

2. Define Build Steps: Create a configuration file for the chosen CI/CD tool that defines the build steps necessary to create a container image from the provided Dockerfile.

   For instance, in GitHub Actions, create a .github/workflows/ci.yml file with the following content:

   name: CI
   
   on:
     push:
       branches:
         - main
   
   jobs:
     build:
       runs-on: ubuntu-latest
   
       steps:
         - name: Checkout code
           uses: actions/checkout@v2
   
         - name: Set up Docker Buildx
           uses: docker/setup-buildx-action@v1
   
         - name: Build Docker image
           run: |
             docker build -t balena-exporter .
   
         - name: Run Tests
           run: |
             docker run balena-exporter python -m unittest discover -s tests
   

3. Configure Deployment Steps: Add deployment steps to your CI/CD configuration to push the built Docker image to a container registry (e.g., Docker Hub, GitHub Container Registry) or deploy to a governance platform.

   Example of a deployment step using GitHub Actions:

   jobs:
     deploy:
       runs-on: ubuntu-latest
       needs: build
   
       steps:
         - name: Login to Docker Hub
           uses: docker/login-action@v1
           with:
             username: ${{ secrets.DOCKER_USERNAME }}
             password: ${{ secrets.DOCKER_PASSWORD }}
   
         - name: Push Docker image
           run: |
             docker tag balena-exporter yourusername/balena-exporter:latest
             docker push yourusername/balena-exporter:latest
   

4. Environment Variables: Ensure that any required environment variables such as BALENA_TOKEN and potentially CRAWL_INTERVAL are set in the CI/CD configuration, especially for deployments that require these variables at runtime.

5. Continuous Testing: Integrate testing as part of the CI pipeline. This ensures that code changes do not break existing functionality. An example can be seen in the testing process, which leverages unittest.

   The test snippet from tests/test_exporter.py shows unit tests that can be executed in your CI/CD pipeline:

   def test_collect(self, mock_metrics):
       with mock.patch.object(self.collector, "get_balena_fleets") as mock_fleets:
           mock_fleets.return_value = ["fleet1", "fleet2"]
           mock_metrics.side_effect = [("test_fleet", 3), ("test_fleet", 3)]
   
           result = list(self.collector.collect()[0].samples)
           expected = [('balena_devices_online', {'fleet_name': 'test_fleet'}, 3),
                       ('balena_devices_online', {'fleet_name': 'test_fleet'}, 3)]
   
           result = [(s.name, s.labels, s.value) for s in result]
   
           self.assertEqual(result, expected)
   

6. Monitoring and Alerts: Integrate monitoring and alerting for your deployed applications to ensure stability and performance over time.

By implementing these next steps, the screenly/balena-prometheus-exporter project can achieve a robust CI/CD pipeline for continuous integration and deployment.

All information is sourced from the project files and code snippets provided.