76.1 Project 40: Canary release with Argo Rollouts

echo 'Canary sends a small percent of traffic to the new version first'

echo 'Argo Rollouts adds a Rollout CRD that can weight traffic with Ingress or Service mesh'

echo 'Lab pattern without mesh: two ReplicaSets and a manual weight via Service subsets tip'

echo 'Install tip: apply Argo Rollouts manifests from argo-rollouts.readthedocs.io'

echo 'kubectl create namespace argo-rollouts'

echo 'kubectl get pods -n argo-rollouts'

mkdir -p /tmp/k8s40 && printf '%s\n' 'apiVersion: argoproj.io/v1alpha1' 'kind: Rollout' 'metadata: {name: shop-canary}' 'spec:' '  replicas: 5' '  strategy:' '    canary:' '      steps:' '      - setWeight: 20' '      - pause: {duration: 30}' '      - setWeight: 50' '      - pause: {duration: 30}' '      - setWeight: 100' '  selector: {matchLabels: {app: shop-canary}}' '  template:' '    metadata: {labels: {app: shop-canary}}' '    spec:' '      containers:' '      - name: web' '        image: nginx:1.27-alpine' '        ports: [{containerPort: 80}]' > /tmp/k8s40/rollout.yaml && grep -A6 'canary:' /tmp/k8s40/rollout.yaml

echo 'kubectl apply -f /tmp/k8s40/rollout.yaml'

echo 'kubectl argo rollouts get rollout shop-canary'

echo 'First deploy uses the stable ReplicaSet at 100 percent'

echo 'Image bump creates a canary ReplicaSet at setWeight percent'

echo 'kubectl set image rollout/shop-canary web=nginx:1.27-alpine'

echo 'pause steps let humans or analysis decide before more weight'

echo 'kubectl argo rollouts promote shop-canary'

echo 'kubectl argo rollouts abort shop-canary'

echo 'AnalysisTemplate can fail the canary on error-rate metrics'

echo 'Without mesh, use Ingress canary annotations from your controller docs'

echo 'Never skip the abort path in a drill'

printf '%s\n' 'apiVersion: v1' 'kind: Service' 'metadata: {name: shop-canary}' 'spec:' '  selector: {app: shop-canary}' '  ports: [{port: 80}]' > /tmp/k8s40/svc.yaml && cat /tmp/k8s40/svc.yaml

echo 'kubectl apply -f /tmp/k8s40/svc.yaml'

echo 'Stable Service name keeps clients unchanged during canary'

echo 'Compare: blue-green flips all traffic; canary ramps percent'

echo 'Use canary for risky payment paths; blue-green for config flips'

echo 'Record error rate before promote in your notebook'

echo 'kubectl argo rollouts undo shop-canary'

echo 'Rollout history is in the Rollout status object'

echo 'Image digests beat floating tags for canary honesty'

echo 'Kind lab: install plugin kubectl-argo-rollouts for the CLI subcommand'

echo 'If CRDs missing, the apply will fail until the controller is installed'

echo 'Read the Rollout status.phase field after each step'

echo 'Optional cleanup: kubectl delete rollout shop-canary svc shop-canary'

echo 'Keep notes of setWeight values that felt safe in the drill'

echo 'Next project packages this app as a Helm chart'

echo 'Canary steps include setWeight 20 then 50 then 100'

echo 'Abort command practiced: kubectl argo rollouts abort'

echo 'Vikram: PASS'