Kubenetes 中使用 Traefik 作为 Ingress 转发流量

September 8, 2019 · 346 words · 2 min

Kubenetes 中使用 Traefik 作为 Ingress 转发流量

Ingress 就是 Kubernetes 机器外访问集群的入口，将请求的 URL 转发到不同的 Service 上，相当于 Nginx 等代理服务器路由信息由 Ingress Controller 提供，Ingress Controller 可以理解为监视器，不断请求 Kubernetes API 实时感知 Service 和 Pod 的状态，结合上下文的 Ingress 生成配置，然后更新反向代理服务器的配置，达到服务发现的作用

Traefik 是一个开源的反向代理与负载均衡工具，能够与常见的微服务系统直接整合，可以实现自动化动态配置

通过配置文件部署 Traefik

配置

Ingress-rbac.yaml

用于 Service Account 验证

apiVersion: v1
kind: ServiceAccount
metadata:
  name: ingress
  namespace: kube-system

---

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: ingress
subjects:
  - kind: ServiceAccount
    name: ingress
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

traefik-daemon-set.yaml

使用 DaemonSet 部署 Traefik

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: traefik-ingress-lb
  namespace: kube-system
  labels:
    k8s-app: traefik-ingress-lb
spec:
  template:
    metadata:
      labels:
        k8s-app: traefik-ingress-lb
        name: traefik-ingress-lb
    spec:
      terminationGracePeriodSeconds: 60
      hostNetwork: true
      restartPolicy: Always
      serviceAccountName: ingress
      containers:
      - image: traefik
        name: traefik-ingress-lb
        resources:
          limits:
            cpu: 200m
            memory: 30Mi
          requests:
            cpu: 100m
            memory: 20Mi
        ports:
        - name: http
          containerPort: 80
          hostPort: 80
        - name: admin
          containerPort: 8580
          hostPort: 8580
        args:
        - --web
        - --web.address=:8580
        - --kubernetes

traefik-ui.yaml

创建 Traefik 的 UI

apiVersion: v1
kind: Service
metadata:
  name: traefik-web-ui
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress-lb
  type: NodePort  
  ports:
  - name: web
    port: 80
    targetPort: 8580
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: traefik-web-ui
  namespace: kube-system
spec:
  rules:
  - host: traefik-ui.local
    http:
      paths:
      - path: /
        backend:
          serviceName: traefik-web-ui
          servicePort: web

部署

kubectl apply -f .

通过 Helm 部署 Traefik

创建 values.yaml

dashboard:
  enabled: true
  domain: dashboard.traefik
serviceType: LoadBalancer
rbac:
  enabled: true
deployment:
  hostPort:
    httpEnabled: true
    httpsEnabled: true
    dashboardEnabled: true

helm install --values values.yaml stable/traefik --name traefik

这样就会启用 Dashboard，更改 Host 指向相应的节点和端口，访问dashboard.traefik:${PORT}就可以看到 Dashboard

Host

192.168.0.110 dashboard.traefik

也可以直接下载 Traefik 的 Helm Release，解压后修改相应的配置后再安装

helm fetch stable/traefik

tar -xvf traefik-1.24.1.tgz

helm install --values values.yaml ./traefik --name traefik

部署应用

backend-ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: backend-ingress
  namespace: default
spec:
  rules:
  - host: rest.hellowoodes.com
    http:
      paths:
      - path: /
        backend:
          serviceName: backend
          servicePort: 8080

修改 Host 将域名指向相应的节点 IP

测试

获取端口

kubectl get service -l app=traefik

NAME               TYPE          CLUSTER-IP      EXTERNAL-IP  PORT(S)                     AGE
traefik            LoadBalancer  10.106.137.170  <pending>    80:32311/TCP,443:30677/TCP  1s
traefik-dashboard  ClusterIP     10.108.91.184   <none>       80/TCP                      1s

访问相应的 NodeIP 和地址 http://dashboard.traefik:32311，可以看到 Traefik 的 Dashboard
因为在values.yaml 中已经配置了 deployment.hostPort.httpEnabled和deployment.hostPort.httpsEnabled，所以也可以直接访问 dashboard.traefik

访问backend 应用

curl http://rest.hellowoodes.com/ping
Pong%

参考资料

Spring Cloud 使用 Kubernetes 作为注册中心 Kubernetes 中使用 Helm 部署应用