kubernetes中traefik部署安裝

參考github項目地址https://github.com/containous/traefik

文檔地址： https://docs.traefik.io/

以下配置文件均可在https://github.com/containous/traefik/tree/master/examples/k8s找到

一 部署

traefik 有兩種部署方式，一種是通過deamonset形式，一種是通過deployment的形式。兩個形式各有優勢。

使用deployment,可伸縮性可以更好

使用deamonset，Single-Pod-per-Node。當節點加入羣集時，DaemonSet會自動擴展到新節點。DaemonSet可以使用NET_BIND_SERVICE功能運行，這將允許它綁定到每個主機上的端口80/443 / etc。這將允許繞過kube-proxy，並減少流量跳躍。

首先創建rbac文件

##traefik-rbac.yaml

---
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

 

##traefik-ds.yaml

---
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
      containers:
      - image: traefik
        name: traefik-ingress-lb
        ports:
        - name: http
          containerPort: 80
          hostPort: 80
        - name: admin
          containerPort: 8080
          hostPort: 8580
        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

deamonset的方式在配置文件中直接暴露機器的端口，由hostPort實現。訪問時未使用的kube-proxy.

##traefik-deployment.yaml

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
  labels:
    k8s-app: traefik-ingress-lb
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: traefik-ingress-lb
  template:
    metadata:
      labels:
        k8s-app: traefik-ingress-lb
        name: traefik-ingress-lb
    spec:
      serviceAccountName: traefik-ingress-controller
      terminationGracePeriodSeconds: 60
      containers:
      - image: traefik
        name: traefik-ingress-lb
        ports:
        - name: http
          containerPort: 80
        - name: admin
          containerPort: 8080
        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
  type: NodePort

deployment 的形式通過nodePort的形式暴露訪問的端口。

創建

#創建rbac
kubectl create -f traefik-rbac.yaml

#創建服務
kubectl create -f traefik-ds.yaml
或者：
kubectl create -f traefik-deployment.yaml

二 使用

創建到服務的Ingress

example：traefik web界面的訪問

###traefik-ingress.yaml 

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: traefik-web-ui
  namespace: kube-system
spec:
  tls:
  - secretName: traefik-cert
  rules:
  - host: traefik-ui.k8s
    http:
      paths:
      - path: /
        backend:
          serviceName: traefik-ingress-service
          servicePort: 8080

注： 此處的servicePort，可以是8080，也可以用name表示，如下：

###traefik-ingress2.yaml

---
apiVersion: v1
kind: Service
metadata:
  name: traefik-web-ui
  namespace: kube-system
spec:
  type: NodePort
  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
spec:
  rules:
  - host: traefik-ui.k8s
    http:
      paths:
      - path: /
        backend:
          serviceName: traefik-web-ui
          servicePort: web

三 訪問

將Ingress中的host 添加到本地的hosts文件中，形式： [節點IP  host]

添加完成後即可通過瀏覽器訪問。

四 同一個域名，區分路徑

example:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: cheeses
  annotations:
    traefik.frontend.rule.type: PathPrefixStrip
spec:
  rules:
  - host: cheeses.minikube
    http:
      paths:
      - path: /stilton
        backend:
          serviceName: stilton
          servicePort: http
      - path: /cheddar
        backend:
          serviceName: cheddar
          servicePort: http
      - path: /wensleydale
        backend:
          serviceName: wensleydale
          servicePort: http

traefik.frontend.rule.type: PathPrefixStrip 必須放在ingress的annotations中，纔可以生效。

五 訪問調度

對於後臺有多個副本的服務，默認的調度是：輪詢調度。

可以在service的annotations中，配置traefik.ingress.kubernetes.io/load-balancer-method: drr

調度算法更改爲動態輪詢，根據每次調度到的服務動態調整權重。