blue-green-deploy

Blue-Green Deployment with Real HTTP Health Checks

Deploying a new version directly to production means any failure is immediately customer- facing. This workflow deploys to the green environment (4 containers), runs health checks (real HTTP requests with response time validation), switches traffic from blue to green via DNS, and verifies the deployment is stable (0.01% error rate, 52ms p99 latency).

Workflow

appName, newVersion, currentEnv
              |
              v
+---------------------+     +-------------------+     +----------------------+     +---------------------------+
| bg_prepare_green    | --> | bg_test_green     | --> | bg_switch_traffic    | --> | bg_verify_deployment      |
+---------------------+     +-------------------+     +----------------------+     +---------------------------+
  4 containers deployed      real HTTP health          activeEnv: green             errorRate: 0.01%
  imageTag set               checks + response         dnsUpdated: true             p99Latency: 52ms
  readyAt timestamp          time validation                                        rollbackAvailable: true

Workers

PrepareGreenWorker -- Deploys appName:newVersion to green with containersDeployed: 4.

TestGreenWorker -- Runs real HTTP health checks via HttpClient, validates response time, checks the active environment matches "green", and verifies the version. Outputs testsPassed and testsFailed counts.

SwitchTrafficWorker -- Switches traffic from currentEnv to green. Sets dnsUpdated: true.

VerifyDeploymentWorker -- Confirms the deployment: errorRate: "0.01%", p99Latency: "52ms", rollbackAvailable: true.

Tests

8 unit tests cover green preparation, health check scenarios, traffic switching, and verification.

Running

See ../../RUNNING.md for setup and execution instructions.