使用skipper實現Blue-Green deployments

1 創建skipper角色


# cat cat role.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
  name: skipper-ingress-serviceaccount
  namespace: kube-system

---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: skipper-ingress-clusterrole
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - "extensions"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ""
    resources:
        - events
    verbs:
        - create
        - patch
  - apiGroups:
      - "extensions"
    resources:
      - ingresses/status
    verbs:
      - update

---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: skipper-ingress-role
  namespace: kube-system
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get

---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: skipper-ingress-role-nisa-binding
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: skipper-ingress-role
subjects:
  - kind: ServiceAccount
    name: skipper-ingress-serviceaccount
    namespace: kube-system

---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: skipper-ingress-clusterrole-nisa-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: skipper-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: skipper-ingress-serviceaccount
    namespace: kube-system
# kubectl create -f role.yaml

2 創建skipper-ingress controller

# cat skipper-ingress-ds.yaml
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: skipper-ingress
  namespace: kube-system
  labels:
    application: skipper-ingress
    version: v0.10.5
    component: ingress
spec:
  selector:
    matchLabels:
      application: skipper-ingress
  updateStrategy:
    type: RollingUpdate
  template:
    metadata:
      name: skipper-ingress
      labels:
        application: skipper-ingress
        version: v0.10.13
        component: ingress
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      serviceAccountName: skipper-ingress-serviceaccount
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: master
                operator: DoesNotExist
      tolerations:
      - key: CriticalAddonsOnly
        operator: Exists
      hostNetwork: true
      containers:
      - name: skipper-ingress
        image: registry.opensource.zalan.do/pathfinder/skipper:v0.10.13
        ports:
        - name: ingress-port
          containerPort: 9999
          hostPort: 9999
        args:
          - "skipper"
          - "-kubernetes"
          - "-kubernetes-in-cluster"
          - "-address=:9999"
          - "-proxy-preserve-host"
          - "-serve-host-metrics"
          - "-enable-ratelimits"
          - "-experimental-upgrade"
          - "-metrics-exp-decay-sample"
          - "-lb-healthcheck-interval=3s"
          - "-metrics-flavour=codahale,prometheus"
          - "-enable-connection-metrics"
        resources:
          requests:
            cpu: 25m
            memory: 25Mi
        readinessProbe:
          httpGet:
            path: /kube-system/healthz
            port: 9999
          initialDelaySeconds: 5
          timeoutSeconds: 5
# kubectl create -f skipper-ingress-ds.yaml

3 測試Blue-Green deployments\
創建hello-world service:

# kubectl run hello-world --image=tutum/hello-world --replicas=2 --port=80
# kubectl expose deploy hello-world

創建skipper demo service

# cat demo-deployment.yaml 
apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: skipper-demo
spec:
  replicas: 2
  template:
    metadata:
      labels:
        application: skipper-demo
    spec:
      containers:
      - name: skipper-demo
        image: registry.opensource.zalan.do/pathfinder/skipper:v0.10.5
        args:
          - "skipper"
          - "-inline-routes"
          - "* -> inlineContent(\"<body style='color: white; background-color: green;'><h1>Hello!</h1>\") -> <shunt>"
        ports:
        - containerPort: 9090

# cat demo-svc.yaml 
apiVersion: v1
kind: Service
metadata:
  name: skipper-demo
  labels:
    application: skipper-demo
spec:
  type: ClusterIP
  ports:
    - port: 80
      protocol: TCP
      targetPort: 9090
      name: external
  selector:
    application: skipper-demo
# kubectl create -f demo-deployment.yaml
# kubectl create -f demo-svc.yaml

創建ingress

# cat demo-ing.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: skipper-demo
  annotations:
    zalando.org/backend-weights: |
      {"skipper-demo": 20, "hello-world": 80}
spec:
  rules:
  - host: skipper-demo.mydomain.org
    http:
      paths:
      - backend:
          serviceName: skipper-demo
          servicePort: 80
      - backend:
          serviceName: hello-world
          servicePort: 80
# kubectl create -f demo-ing.yaml

測試：

# kubectl get svc
NAME           TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
hello-world    ClusterIP   10.100.216.64   <none>        80/TCP    25m
kubernetes     ClusterIP   10.96.0.1       <none>        443/TCP   4h
skipper-demo   ClusterIP   10.111.89.2     <none>        80/TCP    4h

# kubectl get ing
NAME           HOSTS                       ADDRESS   PORTS     AGE
skipper-demo   skipper-demo.mydomain.org             80        46m