Traefik和Nginx-Ingress-Controller的部署

前言

Traefik

Traefik是一个用Golang开发的轻量级的Http反向代理和负载均衡器。由于可以自动配置和刷新backend节点，目前可以被绝大部分容器平台支持，例如Kubernetes，Swarm，Rancher等。由于traefik会实时与Kubernetes API交互,所以对于Service的节点变化，traefik的反应会更加迅速。总体来说traefik可以在Kubernetes中完美的运行.

Nginx-Ingress-Controller

Nginx-Ingress-Controller对于绝大多数刚刚接触k8s的人来说都比较熟悉，一个对外暴露service的7层反向代理。目前最新代号0.9.0-beta.15，可见目前nginx-ingress-control仍然处于beta版本。不过接触过的人还是明白nginx-ingress-control强大的Annotate配置，可以为service提供丰富的个性化配置，这点对于traefik来说是目前还无法打到的地步。

部署

Traefik

1. 创建RBAD权限规则

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

2. 定义deployment部署

在这里官方主要定义了两种部署模式，分别是Daemonset和Deployment，它们之间的区别主要是：

相比一个节点只部署一个daemonset的traefik，采用deployment会更易于伸缩和扩展；
Daemonset可以利用taints和tolerations字段在自定义的节点上部署traefik服务；
采用Daemonset方式，可以在任何节点上访问80和443端口，而使用deployment者必须依赖service里面定义的对象去访问。

由于我们要在kubernetes机群里部署多个ingress服务，这里就统一采用deployment的方式来部署了。

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
        args:
        - --web
        - --kubernetes
        - --web.metrics
        - --web.metrics.prometheus
        - --accesslog
        - --accesslog.filepath=/var/log/traefik_access.log
        - --traefiklog
        - --traefiklog.filepath=/var/log/traefik.log
        - --traefiklogsfile=traefik.log
        - --api
        - --loglevel=INFO
        - --metrics.prometheus
---
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

3. 配置Traefik的UI界面

Traefik的UI用的是AngularJS写的一个简洁的界面，启动默认的端口是8080。

apiVersion: v1
kind: Service
metadata:
  name: traefik-web-ui
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress-lb
  ports:
  - 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.minikube
    http:
      paths:
      - backend:
          serviceName: traefik-web-ui
          servicePort: 80

4. 使用

对于使用，相信编辑过ingress的人都用过，我这里都不在累述了，主要讲下Traefik在Kubernetes中Annotate的配置吧。

通用配置

kubernetes.io/ingress.class: traefik

Ingress声明，这里声明了ingress后端采用traefik实现，而不是nginx的controller
ingress.kubernetes.io/whitelist-source-range: "1.2.3.0/24, fe80::/16"

配置访问白名单，支持ipv4和ipv6
ingress.kubernetes.io/auth-type: basic

http认证模式，此处为basic模式
ingress.kubernetes.io/auth-secret: mysecret

basic认证的对应的username和password，这里对应的traefik所在kubernetes命名空间里的secrets

前端配置

traefik.frontend.rule.type: PathPrefixStrip

对于在前端配置多个路径转发时，必须配置改选项。例如：

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: cheeses
  annotations:
    kubernetes.io/ingress.class: traefik
    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.priority: "3"

配置前端的权重，值越高则优先匹配
traefik.frontend.passHostHeader: "false"

关闭传入Hearder
traefik.protocol=https

使用https协议
traefik.frontend.entryPoints=http,https

同时支持http和https

后端配置

traefik.backend.loadbalancer.method=drr

后端Service的负载均衡策略，目前traefik支持的策略包括：wrr（加权轮训调度算法）和drr（动态加权循环调度算法）
traefik.backend.loadbalancer.stickiness=true

是否开启负载均衡器的session亲和性
traefik.backend.loadbalancer.stickiness.cookieName=NAME

手动配置后端session亲和性的cookie名称
traefik.backend.loadbalancer.sticky=true

弃用

健康检查

traefik.backend.healthcheck.path=/health

traefik的监控检查路径
traefik.backend.healthcheck.interval=5s

健康检查的时间间隔
traefik.backend.circuitbreaker: "NetworkErrorRatio() > 0.5"

监测某台节点上的服务错误率达到50%时，自动下线该节点。
traefik.backend.circuitbreaker: "LatencyAtQuantileMS(50.0) > 50"

监测某台节点上服务的延时大于50ms时，自动下线该节点。
traefik.backend.circuitbreaker: "ResponseCodeRatio(500, 600, 0, 600) > 0.5"

监测某台节点上服务返回状态码为[500-600]在[0-600]区间占比超过50%时，自动下线该节点。

Nginx-Ingress-Controller

1. 创建RBAC权限规则和ServiceAccount账号

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

---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: nginx-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: nginx-ingress-role
  namespace: kube-system
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    resourceNames:
      # Defaults to "<election-id>-<ingress-class>"
      # Here: "<ingress-controller-leader>-<nginx>"
      # This has to be adapted if you change either parameter
      # when launching the nginx-ingress-controller.
      - "ingress-controller-leader-nginx"
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get

---

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

---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: nginx-ingress-clusterrole-nisa-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: nginx-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: kube-system

2. 创建nginx-ingress-controller的configmap文件

我在这里添加了一个tcp-configmap，用来做tcp端口的代理。

apiVersion: v1
data:
  enable-vts-status: "true"
kind: ConfigMap
metadata:
  name: ingress-configmap
  namespace: kube-system
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: ingress-controller-leader-nginx
  namespace: kube-system
---
apiVersion: v1
data:
kind: ConfigMap
metadata:
  name: tcp-configmap
  namespace: kube-system

3. 创建nginx-ingress-controller的default-http-backend

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    k8s-app: default-http-backend
  name: default-http-backend
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: default-http-backend
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        k8s-app: default-http-backend
    spec:
      containers:
      - image: index.tenxcloud.com/google_containers/defaultbackend:1.1
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 5
        name: default-http-backend
        ports:
        - containerPort: 8080
          protocol: TCP
        resources:
          limits:
            cpu: 10m
            memory: 20Mi
          requests:
            cpu: 10m
            memory: 20Mi
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 60

---
apiVersion: v1
kind: Service
metadata:
  name: default-http-backend
  namespace: kube-system
  labels:
    k8s-app: default-http-backend
spec:
  ports:
  - port: 80
    targetPort: 8080
  selector:
    k8s-app: default-http-backend

4. 创建nginx-ingress-controller

这里可以关注下nginx-ingress-controller的启动参数--tcp-services-configmap，该参数会watch我们之前定义的tcp-configmap文件，对定义的tcp端口做4层的负载均衡。值得注意的是，tcp-configmap里面定义的端口是不能重复的。

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
  labels:
    k8s-app: nginx-ingress-controller
  name: nginx-ingress-controller
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: nginx-ingress-controller
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        k8s-app: nginx-ingress-controller
    spec:
      containers:
      - args:
        - /nginx-ingress-controller
        - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
        - --configmap=kube-system/ingress-configmap
        - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-configmap
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace
        image: index.int.jumei.com/gcr.io/google-containers/nginx-ingress-controller-amd64:0.9.0-beta.15
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
          initialDelaySeconds: 10
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        name: nginx-ingress-controller
        ports:
        - containerPort: 80
          hostPort: 80
          protocol: TCP
        - containerPort: 443
          hostPort: 443
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        securityContext:
          privileged: true
      dnsPolicy: ClusterFirst
      serviceAccount: nginx-ingress-serviceaccount
      serviceAccountName: nginx-ingress-serviceaccount
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-ingress-controller
  namespace: kube-system
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
    name: http
  - port: 443
    protocol: TCP
    targetPort: 443
    name: https
  selector:
    k8s-app: nginx-ingress-controller
  sessionAffinity: None
  type: ClusterIP

5. 使用

对于ingress的使用我这里留到下次更文总结。

总结

这两天通过对Traefik和Nginx-ingress-controller的使用，发现绝大多数场景Traefik都能满足我的需求，不的不说这个后起之秀是要把前辈们拍到沙滩上的节奏啊，Traefik对于Kubernetes友好和迅捷的支持还是值得大家去体验一下。目前Traefik在Github上的star已经超过了1.2W,发布了200多个releases，可见热度不低。另外Traefik对于那种每天处于多次添加、删除、被killed，升级、降级折腾的微服务来说，简直都是神器啊，完全不用关心去配置traefik的后端，因为它已经自动帮你监听了service的变化，并轻松的更改其配置和热重新加载，这也从官网给出http代理图可见一二。