20_1.服务暴露-ingress (traefik)

末蓝、 2022-10-07 00:59 194阅读 0赞

### 20\_1.服务暴露-ingress (traefik) ###

#### 一.ingress 简介 ####

Ingress是建立在Service之上的L7访问入口。  
Ingress是K8S API的标准资源类型之一，也是一种核心资源，基于域名和URL路径，把用户的请求（可以来源于集群外部）转发至指定Service的资源，从而实现服务暴露  
**Ingress控制器** 可以为Ingress资源监听某套接字，根据Ingress规则路由调度流量  
常用的Ingress控制器的实现软件有：Ingress-nginx、HAProxy、Traefik等  
下面以Traefik为例

#### 二.traefik ####

[https://github.com/traefik/traefik][https_github.com_traefik_traefik]  
[Kubernetes 中使用 Traefik 2.1][Kubernetes _ Traefik 2.1]  
[Kubernetes部署Ingress Traefik v2.2][Kubernetes_Ingress Traefik v2.2]

##### 1. 简介 #####

Traefik 是一个开源的可以使服务发布变得轻松有趣的边缘路由器。它负责接收你系统的请求，然后使用合适的组件来对这些请求进行处理。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1_size_16_color_FFFFFF_t_70]

除了众多的功能之外，Traefik 的与众不同之处还在于它会自动发现适合你服务的配置。当 Traefik 在检查你的服务时，会找到服务的相关信息并找到合适的服务来满足对应的请求。  
Traefik 兼容所有主流的集群技术，比如 Kubernetes，Docker，Docker Swarm，AWS，Mesos，Marathon，等等；并且可以同时处理多种方式。（甚至可以用于在裸机上运行的比较旧的软件。）  
使用 Traefik，不需要维护或者同步一个独立的配置文件：因为一切都会自动配置，实时操作的（无需重新启动，不会中断连接）。使用 Traefik，你可以花更多的时间在系统的开发和新功能上面，而不是在配置和维护工作状态上面花费大量时间。

##### 2. 核心概念 #####

Traefik 是一个边缘路由器，是你整个平台的大门，拦截并路由每个传入的请求：它知道所有的逻辑和规则，这些规则确定哪些服务处理哪些请求；传统的反向代理需要一个配置文件，其中包含路由到你服务的所有可能路由，而 Traefik 会实时检测服务并自动更新路由规则，可以自动服务发现。  
![traefik architecture overview][]

首先，当启动 Traefik 时，需要定义 entrypoints（入口点），然后，根据连接到这些 entrypoints 的路由来分析传入的请求，来查看他们是否与一组规则相匹配，如果匹配，则路由可能会将请求通过一系列中间件转换过后再转发到你的服务上去。在了解 Traefik 之前有几个核心概念我们必须要了解：

*  `Providers` 用来自动发现平台上的服务，可以是编排工具、容器引擎或者 key-value 存储等，比如 Docker、Kubernetes、File
 *  `Entrypoints` 监听传入的流量（端口等…），是网络入口点，它们定义了接收请求的端口（HTTP 或者 TCP）。
 *  `Routers` 分析请求（host, path, headers, SSL, …），负责将传入请求连接到可以处理这些请求的服务上去。
 *  `Services` 将请求转发给你的应用（load balancing, …），负责配置如何获取最终将处理传入请求的实际服务。
 *  `Middlewares` 中间件，用来修改请求或者根据请求来做出一些判断（authentication, rate limiting, headers, …），中间件被附件到路由上，是一种在请求发送到你的服务之前（或者在服务的响应发送到客户端之前）调整请求的一种方法。

#### 三.k8s部署traefik ####

> 参考资料:  
> [Kubernetes 中使用 Traefik 2.1][Kubernetes _ Traefik 2.1]  
> [Kubernetes部署Ingress Traefik v2.2][Kubernetes_Ingress Traefik v2.2]

##### 0.部署准备 #####

由于 Traefik 2.X 版本和之前的 1.X 版本不兼容，我们这里选择功能更加强大的 2.X 版本来和大家进行讲解，我们这里使用的镜像是 traefik:2.2。  
在 Traefik 中的配置可以使用两种不同的方式：

*  静态配置：启动配置  
    静态配置中的元素（这些元素不会经常更改）连接到 providers 并定义 Treafik 将要监听的 entrypoints。  
    在 Traefik 中有三种方式定义静态配置：在配置文件中、在命令行参数中、通过环境变量传递
 *  动态配置：完全动态的路由配置  
    动态配置包含定义系统如何处理请求的所有配置内容，这些配置是可以改变的，而且是无缝热更新的，没有任何请求中断或连接损耗。

准备镜像:  
`docker pull traefik:v2.2`  
`docker tag traefik:v2.2 harbor.hzwod.com/k8s/traefik:v2.2`  
`docker push harbor.hzwod.com/k8s/traefik:v2.2`

##### 1. 资源配置清单 #####

[https://github.com/traefik/traefik/tree/v1.7/examples/k8s][https_github.com_traefik_traefik_tree_v1.7_examples_k8s]  
参考官网文档-CRD定义[https://doc.traefik.io/traefik/user-guides/crd-acme/][https_doc.traefik.io_traefik_user-guides_crd-acme]

*  config list  
    配置详细内容见文末附录  
    `traefik_crd.yaml` 查看  
    `traefik_rbac.yaml` 查看  
    `traefik_dp.yaml` 查看  
    添加demo服务用于演示效果  
    `whoami_ingressRoute.yaml` 查看  
    `whoami_dp.yaml` 查看  
    traefik\_dp.yaml 部分args说明：

# 创建一个名为 api@internal 的特殊 service，在 dashboard 中可以直接使用这个 service 来访问
     - --api=true
    # 定义 web 入口
    - --entrypoints.web.Address=:8000
    # 定义websecure 入口
    - --entrypoints.websecure.Address=:4443
    # 开启 k8s ingress provider
    - --providers.kubernetesingress
    # 开启 k8s CRD provider
    - --providers.kubernetescrd
    # 指定k8s入口（貌似traefik pod固定在master节点上就不需要指定？？）
    - --kubernetes.endpoint=https://172.10.10.10:7443

*  应用资源到k8s

kubectl apply -f traefik_crd.yaml         
    kubectl apply -f traefik_rbac.yaml        
    kubectl apply -f traefik_dp.yaml          
    kubectl apply -f whoami_ingressRoute.yaml 
    kubectl apply -f whoami_dp.yaml

*  查看资源  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1_size_16_color_FFFFFF_t_70 1]
 *  访问traefik dashbord  
    ![在这里插入图片描述][20210615143330389.gif]
 *  服务访问测试  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1_size_16_color_FFFFFF_t_70 2]![在这里插入图片描述][20210615143440770.gif]

#### 附录 ####

*   traefik\_crd.yaml  
    back to config list

# All resources definition must be declared
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: ingressroutes.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: IngressRoute
        plural: ingressroutes
        singular: ingressroute
      scope: Namespaced
    ---
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: middlewares.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: Middleware
        plural: middlewares
        singular: middleware
      scope: Namespaced
    ---
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: ingressroutetcps.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: IngressRouteTCP
        plural: ingressroutetcps
        singular: ingressroutetcp
      scope: Namespaced
    ---
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: ingressrouteudps.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: IngressRouteUDP
        plural: ingressrouteudps
        singular: ingressrouteudp
      scope: Namespaced
    ---
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: tlsoptions.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: TLSOption
        plural: tlsoptions
        singular: tlsoption
      scope: Namespaced
    ---
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: tlsstores.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: TLSStore
        plural: tlsstores
        singular: tlsstore
      scope: Namespaced
    ---
    apiVersion: apiextensions.k8s.io/v1beta1
    kind: CustomResourceDefinition
    metadata:
      name: traefikservices.traefik.containo.us
    spec:
      group: traefik.containo.us
      version: v1alpha1
      names:
        kind: TraefikService
        plural: traefikservices
        singular: traefikservice
      scope: Namespaced

*   traefik\_rbac.yaml  
    back to config list

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
      - apiGroups:
          - extensions
        resources:
          - ingresses/status
        verbs:
          - update
      - apiGroups:
          - traefik.containo.us
        resources:
          - middlewares
          - ingressroutes
          - traefikservices
          - ingressroutetcps
          - ingressrouteudps
          - tlsoptions
          - tlsstores
        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: default

这里注意namespace要和traefik容器运行的namespace保持一致，否则traefik访问apiserver时会没有授权

*   traefik\_dp.yaml  
    back to config list

---
    kind: ServiceAccount
    apiVersion: v1
    metadata:
      name: traefik-ingress-controller
    ---
    kind: Deployment
    apiVersion: apps/v1
    metadata:
      name: traefik
      labels:
        app: traefik
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: traefik
      template:
        metadata:
          labels:
            app: traefik
        spec:
          serviceAccountName: traefik-ingress-controller
          containers:
            - name: traefik
              image: harbor.hzwod.com/k8s/traefik:v2.2
              args:
                - --log.level=DEBUG
                - --api
                - --api.insecure
                - --entrypoints.web.address=:80
                - --entrypoints.tcpep.address=:8000
                - --entrypoints.udpep.address=:9000/udp
                - --providers.kubernetesingress
                - --providers.kubernetescrd
              ports:
                - name: web
                  containerPort: 80
                - name: admin
                  containerPort: 8080
                - name: tcpep
                  containerPort: 8000
                - name: udpep
                  containerPort: 9000
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: traefiktcp
    spec:
      type: LoadBalancer
      selector:
        app: traefik
      ports:
        - protocol: TCP
          port: 80
          name: web
          targetPort: 80
        - protocol: TCP
          port: 8080
          name: admin
          targetPort: 8080
        - protocol: TCP
          port: 8000
          name: tcpep
          targetPort: 8000
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: traefikudp
    spec:
      type: LoadBalancer
      selector:
        app: traefik
      ports:
        - protocol: UDP
          port: 9000
          name: udpep
          targetPort: 9000

*   whoami\_ingressRoute.yaml  
    back to config list

apiVersion: traefik.containo.us/v1alpha1
    kind: IngressRoute
    metadata:
      name: whoamiingressroute
    spec:
      entryPoints:
        - web
      routes:
      #- match: Host(`foo`) && PathPrefix(`/bar`)
      - match: PathPrefix(`/bar`)
        kind: Rule
        services:
        - name: whoami
          port: 80
    ---
    apiVersion: traefik.containo.us/v1alpha1
    kind: IngressRouteTCP
    metadata:
      name: ingressroute.tcp
    spec:
      entryPoints:
        - tcpep
      routes:
      - match: HostSNI(`bar`)
        kind: Rule
        services:
          - name: whoamitcp
            port: 8080
    ---
    apiVersion: traefik.containo.us/v1alpha1
    kind: IngressRouteUDP
    metadata:
      name: ingressroute.udp
    spec:
      entryPoints:
        - udpep
      routes:
      - kind: Rule
        services:
          - name: whoamiudp
            port: 8080

*   whoami\_dp.yaml  
    back to config list

kind: Deployment
    apiVersion: apps/v1
    metadata:
      name: whoami
      labels:
        app: myapp
        name: whoami
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: myapp
          task: whoami
      template:
        metadata:
          labels:
            app: myapp
            task: whoami
        spec:
          containers:
            - name: whoami
              image: harbor.hzwod.com/k8s/traefik/whoami
              ports:
                - containerPort: 80
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: whoami
    spec:
      ports:
        - name: http
          port: 80
      selector:
        app: myapp
        task: whoami
    ---
    kind: Deployment
    apiVersion: apps/v1
    metadata:
      name: whoamitcp
      labels:
        app: myapp
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: myapp
          task: whoamitcp
      template:
        metadata:
          labels:
            app: myapp
            task: whoamitcp
        spec:
          containers:
            - name: whoamitcp
              image: harbor.hzwod.com/k8s/traefik/whoamitcp
              ports:
                - containerPort: 8080
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: whoamitcp
    spec:
      ports:
        - protocol: TCP
          port: 8080
      selector:
        app: myapp
        task: whoamitcp
    ---
    kind: Deployment
    apiVersion: apps/v1
    metadata:
      name: whoamiudp
      labels:
        app: myapp
        name: whoamiudp
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: myapp
          task: whoamiudp
      template:
        metadata:
          labels:
            app: myapp
            task: whoamiudp
        spec:
          containers:
            - name: whoamiudp
              image: harbor.hzwod.com/k8s/traefik/whoamiudp
              ports:
                - containerPort: 8080
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: whoamiudp
    spec:
      ports:
        - port: 8080
      selector:
        app: myapp
        task: whoamiudp

[https_github.com_traefik_traefik]: https://github.com/traefik/traefik
[Kubernetes _ Traefik 2.1]: https://www.qikqiak.com/k8strain/network/ingress/traefik/
[Kubernetes_Ingress Traefik v2.2]: https://www.ziji.work/ingress/kubernetes-deploy-ingress-traefik-v2-2.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1_size_16_color_FFFFFF_t_70]: /images/20221005/0c75ea4b7e2c42e89d81fd49a8bbea7e.png
[traefik architecture overview]: /images/20221005/e198d48e4b6047438dd3d1a9fd34ac38.png
[https_github.com_traefik_traefik_tree_v1.7_examples_k8s]: https://github.com/traefik/traefik/tree/v1.7/examples/k8s
[https_doc.traefik.io_traefik_user-guides_crd-acme]: https://doc.traefik.io/traefik/user-guides/crd-acme
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1_size_16_color_FFFFFF_t_70 1]: /images/20221005/5038ea9e25304f20acf1a9347ddd1b98.png
[20210615143330389.gif]: /images/20221005/d48e7c3aa760449b87eacb47ca8beb90.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20210615143343525.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE5NjU1NDA1,size_16,color_FFFFFF,t_70
[20210615143440770.gif]: /images/20221005/185d781010a44fa69f78c5409a6a68be.png