Kubernetes 服务入口管理 Traefik Ingress Controller

部署 Traefik

所有的配置文件可以在官方的 github 仓库中找到

Role Based Access Control configuration (Kubernetes 1.6+ only)

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: traefik-ingress-controller
rules:
  - apiGroups:
      - ""
    resources:
      - services
      - endpoints
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: traefik-ingress-controller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-ingress-controller
subjects:
- kind: ServiceAccount
  name: traefik-ingress-controller
  namespace: kube-system

kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/traefik-rbac.yaml

Deploy Traefik using a Deployment or DaemonSet

DaemonSet 会在每台 Node 节点上都创建 Pod 而 Deployment  是人为控制的副本数量（根据实际需求来取决），这里使用 DaemonSet 类型来部署 Traefik。

部署 Traefik（修改 hostNetwork: true）

apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
---
kind: DaemonSet
apiVersion: extensions/v1beta1
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
  labels:
    k8s-app: traefik-ingress-lb
spec:
  template:
    metadata:
      labels:
        k8s-app: traefik-ingress-lb
        name: traefik-ingress-lb
    spec:
      serviceAccountName: traefik-ingress-controller
      terminationGracePeriodSeconds: 60
      hostNetwork: true
      restartPolicy: Always
      containers:
      - image: traefik
        name: traefik-ingress-lb
        ports:
        - name: http
          containerPort: 80
          hostPort: 80
        - name: admin
          containerPort: 8080
          hostPort: 8080
        securityContext:
          capabilities:
            drop:
            - ALL
            add:
            - NET_BIND_SERVICE
        args:
        - --api
        - --kubernetes
        - --logLevel=INFO
---
kind: Service
apiVersion: v1
metadata:
  name: traefik-ingress-service
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress-lb
  ports:
    - protocol: TCP
      port: 80
      name: web
    - protocol: TCP
      port: 8080
      name: admin

https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/traefik-ds.yaml

上述由于修改 hostNetwork: true ，其实已经在每个 Node 节点开放了 80 与 8080 端口，80 提供正常服务，8080 是其自带的 UI 界面。

Ingress 方式暴露 Traefik Web UI

apiVersion: v1
kind: Service
metadata:
  name: traefik-web-ui
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress-lb
  ports:
  - name: web
    port: 80
    targetPort: 8080
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: traefik-web-ui
  namespace: kube-system
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: traefik-ui.com
    http:
      paths:
      - backend:
          serviceName: traefik-web-ui
          servicePort: 80

https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/ui.yaml

下面模拟部署一个程序，已 Nginx  为例：

vi nginx-deployment.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  template:
    metadata:
      labels:
        name: nginx-svc
        namespace: default
spec:
  selector:
    run: nginx-pod
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
---
apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: nginx-pod
spec:
  replicas: 4
  template:
    metadata:
      labels:
        run: nginx-pod
    spec:
      containers:
      - name: nginx
        image: nginx:1.15.5
        ports:
        - containerPort: 80
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ngx-ing
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: k8s.nginx.com
    http:
      paths:
      - backend:
          serviceName: nginx-svc
          servicePort: 80