What is canary deployment?

Question

Accepted Answer

**Canary** — **gradual** update.

```yaml
# Kubernetes Canary
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-canary
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp
      version: canary
  template:
    metadata:
      labels:
        app: myapp
        version: canary
    spec:
      containers:
      - name: myapp
        image: myapp:2.0
```

```yaml
# Routing
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: myapp
spec:
  hosts: [myapp]
  http:
    - route:
        - destination:
            host: myapp
            subset: stable
          weight: 90
        - destination:
            host: myapp
            subset: canary
          weight: 10
```

**Advantages:**
- Minimal risk.
- Real-time metrics.
- Fast rollback.

DevOps: What is canary deployment?