网关

traefik

创建如下docker-compose.yml：

version: '3'

services:
  reverse-proxy:
    # The official v2 Traefik docker image
    image: traefik:v2.9
    # Enables the web UI and tells Traefik to listen to docker
    command: --api.insecure=true --providers.docker
    ports:
      # The HTTP port
      - "80:80"
      # The Web UI (enabled by --api.insecure=true)
      - "8080:8080"
    volumes:
      # So that Traefik can listen to the Docker events
      - /var/run/docker.sock:/var/run/docker.sock
  whoami:
    # A container that exposes an API to show its IP address
    image: traefik/whoami
    labels:
      - "traefik.http.routers.whoami.rule=Path(`/whoami`)"

$ docker-compose up -d
$ docker-compose up -d --scale whoami=2

多次访问http://127.0.0.1/whoami可以发现，IP会在172.22.0.3和172.22.0.4切换，说明已经实现了负载均衡，新增whoami服务实例不再需要调整traefik的配置，就这么好用！

如上配置，只是对whoami容器添加了labels，在labels中路由规则指定了Path。

在k8s中使用

创建如下00-role.yml：

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: traefik-role

rules:
  - apiGroups:
      - ""
    resources:
      - services
      - endpoints
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses/status
    verbs:
      - update

创建如下00-account.yml：

apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-account

创建如下01-role-binding.yml：

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: traefik-role-binding

roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-role
subjects:
  - kind: ServiceAccount
    name: traefik-account
    namespace: default # Using "default" because we did not specify a namespace when creating the ClusterAccount.

创建如下02-traefik.yml：

kind: Deployment
apiVersion: apps/v1
metadata:
  name: traefik-deployment
  labels:
    app: traefik

spec:
  replicas: 1
  selector:
    matchLabels:
      app: traefik
  template:
    metadata:
      labels:
        app: traefik
    spec:
      serviceAccountName: traefik-account
      containers:
        - name: traefik
          image: traefik:v2.9
          args:
            - --api.insecure
            - --providers.kubernetesingress
          ports:
            - name: web
              containerPort: 80
            - name: dashboard
              containerPort: 8080

创建如下02-traefik-services.yml：

apiVersion: v1
kind: Service
metadata:
  name: traefik-dashboard-service

spec:
  type: LoadBalancer
  ports:
    - port: 8080
      targetPort: dashboard
  selector:
    app: traefik
---
apiVersion: v1
kind: Service
metadata:
  name: traefik-web-service

spec:
  type: LoadBalancer
  ports:
    - targetPort: web
      port: 80
  selector:
    app: traefik

$ kubectl apply -f 00-role.yml \
              -f 00-account.yml \
              -f 01-role-binding.yml \
              -f 02-traefik.yml \
              -f 02-traefik-services.yml

traefik已经安装好了，接下来部署应用，创建03-whoami.yml：

kind: Deployment
apiVersion: apps/v1
metadata:
  name: whoami
  labels:
    app: whoami

spec:
  replicas: 3
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      containers:
        - name: whoami
          image: traefik/whoami
          ports:
            - name: web
              containerPort: 80

创建03-whoami-services.yml：

apiVersion: v1
kind: Service
metadata:
  name: whoami

spec:
  ports:
    - name: web
      port: 80
      targetPort: web

  selector:
    app: whoami

创建04-whoami-ingress.yml：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: whoami-ingress
spec:
  rules:
  - http:
      paths:
      - path: /whoami
        pathType: Prefix
        backend:
          service:
            name: whoami
            port:
              name: web

$ kubectl apply -f 03-whoami.yml \
              -f 03-whoami-services.yml \
              -f 04-whoami-ingress.yml

至此部署完毕，curl -v http://localhost/whoami可以看到IP在切换，负载均衡已经生效。

IngressRoute

安装，参考：

# Install Traefik Resource Definitions:
kubectl apply -f https://raw.githubusercontent.com/traefik/traefik/v2.9/docs/content/reference/dynamic-configuration/kubernetes-crd-definition-v1.yml

# Install RBAC for Traefik:
kubectl apply -f https://raw.githubusercontent.com/traefik/traefik/v2.9/docs/content/reference/dynamic-configuration/kubernetes-crd-rbac.yml