Blue-green deployment, also called red-green deployment, runs two application versions in parallel and shifts production traffic from the active version to the new version without visible downtime. A load balancer or routing layer directs traffic between the environments. section 9.3.7
A practical rollout follows these stages:
- Deploy the new version to the inactive server or deployment slot while production traffic remains on the active version. section 9.3.7
- Check readiness through health endpoints, then run automated tests against the new deployment. section 9.4
- Route a small percentage of traffic to the new version, monitor application telemetry, and increase the percentage through controlled stages. section 9.3.7
Azure Web App rollout
A GitHub Actions workflow triggers when a release is published, retrieves versioned release artifacts, authenticates to Azure, creates a staging slot, deploys the application, waits for /health/ready to report Healthy, and runs Playwright tests. Subsequent jobs route 10% and then 30% of traffic to the slot before swapping it into production.
