Rolling Updates and Blue-Green Deployments with Kubernetes and HAProxy

blog20200211-01.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: haproxy-configmap
  namespace: default
data:
  ssl-redirect: "OFF"

blog20200211-02.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: app
  name: app
spec:
  replicas: 5
  selector:
    matchLabels:
      run: app
  template:
    metadata:
      labels:
        run: app
    spec:
      containers:
      - name: app
        image: errm/versions:0.0.1
        ports:
        - containerPort: 3000
        readinessProbe:
          httpGet:
            path: /
            port: 3000
          initialDelaySeconds: 5
          periodSeconds: 5
          successThreshold: 1

blog20200211-03.yaml

apiVersion: v1
kind: Service
metadata:
  name: app-service
spec:
  selector:
    run: app
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 3000

blog20200211-04.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: app-ingress
  namespace: default
spec:
  rules:
  - http:
      paths:
      - path: /
        backend:
          serviceName: app-service
          servicePort: 80

blog20200211-05.sh

$ kubectl apply -f app.yaml -f app-service.yaml -f ingress.yaml

blog20200211-06.sh

$ kubectl get svc haproxy-ingress -n haproxy-controller
NAME              TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)                                     AGE
haproxy-ingress   NodePort   10.101.75.28   <none>        80:31179/TCP,443:31923/TCP,1024:30430/TCP   98s

blog20200211-07.yaml

image: errm/versions:0.0.2

blog20200211-08.sh

$ kubectl apply -f app.yaml

blog20200211-09.sh

$ kubectl rollout status deployment app
deployment "app" successfully rolled out

blog20200211-10.sh

$ kubectl rollout undo deployment app
deployment.extensions/app rolled back

blog20200211-11.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: app
  name: app-blue
spec:
  replicas: 1
  selector:
    matchLabels:
      run: app
      version: 0.0.1
  template:
    metadata:
      labels:
        run: app
        version: 0.0.1
    spec:
      containers:
      - name: app
        image: errm/versions:0.0.1
        ports:
        - containerPort: 3000

blog20200211-12.yaml

apiVersion: v1
kind: Service
metadata:
  name: app-service
spec:
  selector:
    run: app
    version: 0.0.1
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 3000

blog20200211-13.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: app-ingress
  namespace: default
spec:
  rules:
  - http:
      paths:
      - path: /
        backend:
          serviceName: app-service
          servicePort: 80

blog20200211-14.sh

$ kubectl apply -f app-v1.yaml -f app-service-bg.yaml -f ingress.yaml

blog20200211-15.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: app
  name: app-green
spec:
  replicas: 1
  selector:
    matchLabels:
      run: app
      version: 0.0.2
  template:
    metadata:
      labels:
        run: app
        version: 0.0.2
    spec:
      containers:
      - name: app
        image: errm/versions:0.0.2
        ports:
        - containerPort: 3000

blog20200211-16.sh

$ kubectl apply -f app-v2.yaml

blog20200211-17.yaml

apiVersion: v1
kind: Service
metadata:
  name: app-service
spec:
  selector:
    run: app
    version: 0.0.2
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 3000

blog20200211-18.sh

$ kubectl apply -f app-service.yaml

blog20200211-19.yaml

apiVersion: v1
kind: Service
metadata:
  name: test-service
  annotations:
    haproxy.org/path-rewrite: /
spec:
  selector:
    run: app
    version: 0.0.2
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 3000

blog20200211-20.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: app-ingress
  namespace: default
  annotations:
    haproxy.org/ingress.class: "development"
spec:
  rules:
  - http:
      paths:
      - path: /
        backend:
          serviceName: app-service
          servicePort: 80
      - path: /test
        backend:
          serviceName: test-service
          servicePort: 80