| name | deployment-strategies |
| description | Use when choosing or implementing a deployment strategy — provides Blue-Green, Canary, Rolling, and Feature Flag patterns with DORA metrics impact analysis. Extends the pipeline-designer agent. Also triggers on: re-run, update, revise, supplement. |
| metadata | {"category":"harness","harness":"20-cicd-pipeline","agent_type":"general-purpose"} |
Deployment Strategies — Pipeline Deployment Pattern Reference
Reference for deployment strategies with DORA metrics impact analysis, rollback procedures, and implementation guides.
Strategy Comparison
| Strategy | Downtime | Risk | Rollback Speed | Resource Cost | Best For |
|---|
| Recreate | Yes | High | Slow | Low | Non-critical, simple apps |
| Rolling | No | Medium | Medium | Low | Stateless apps, gradual rollout |
| Blue-Green | No | Low | Instant | High (2x infra) | Zero-downtime critical apps |
| Canary | No | Very Low | Fast | Medium | High-traffic apps, risk aversion |
| Feature Flags | No | Minimal | Instant | Low | Complex feature releases |
Blue-Green Deployment
BLUE (current prod) → GREEN (new version)
Load balancer switch: blue → green
Rollback: switch back to blue (< 1 min)
GitHub Actions pattern:
- name: Deploy to Green
run: |
kubectl set image deployment/app-green app=${{ env.IMAGE_TAG }}
kubectl rollout status deployment/app-green
- name: Switch Traffic to Green
run: |
kubectl patch service app-lb -p '{"spec":{"selector":{"slot":"green"}}}'
echo "Traffic switched to green"
Canary Deployment
10% → 25% → 50% → 100% (with health checks at each step)
Rollback: route 100% back to stable
GitHub Actions pattern with manual approval gates:
- name: Canary 10%
run: kubectl apply -f k8s/canary-10.yaml
- name: Wait for approval to increase to 25%
uses: trstringer/manual-approval@v1
with:
secret: ${{ github.TOKEN }}
approvers: ops-team
minimum-approvals: 1
DORA Metrics Impact
| Strategy | Deployment Frequency | Lead Time | MTTR | Change Failure Rate |
|---|
| Recreate | ↓ (fear of downtime) | No change | ↑ (slow rollback) | High |
| Rolling | → | No change | Medium | Medium |
| Blue-Green | ↑ (no downtime fear) | ↓ (fast verify) | ↓ (instant rollback) | Low |
| Canary | ↑↑ (safe to deploy more) | No change | ↓↓ (catch early) | Very Low |
| Feature Flags | ↑↑ (decouple deploy/release) | ↓↓ (deploy anytime) | ↓↓ (flag off) | Very Low |
Rollback Procedures
Blue-Green Rollback
kubectl patch service app-lb -p '{"spec":{"selector":{"slot":"blue"}}}'
Canary Rollback
kubectl delete deployment app-canary
Feature Flag Rollback
launchdarkly feature-flag update my-feature --enabled false
