k8s的对外服务--ingress

service作用体现在两个方面

1、集群内部 不断跟踪pod的变化，更新endpoint中的pod对象，基于pod的IP地址不断变化的一种服务发现机制

2、集群外部 类似负载均衡器，把流量ip+端口，不涉及转发url（http，https），把请求转发到pod

nodePort：容器端口----service端口----nodePort，设定了nodePort，每个节点都会有一个端口被打开，30000-32767

IP+端口 节点ip+30000+32767，实现负载均衡

loadbalancer 云平台上的一种service服务，云平台提供负载均衡ip地址

extrenal 域名映射

ingress 基于域名进行映射，把url（http https）请求转发到service，再由service请求转发到每一个pod

ingress只要一个或者是少量的公网ip或者LB，可以把多个http请求暴漏到外网，七层反向代理

service的service，是一组域名和URL路径，把一个或者多个请求转发到service的规则

先是七层代理----四层代理----pod
 ingress      service	nginx

ingress的组成

ingress是一个api的对象，通过yaml文件来进行配置，ingress的作用是定义请求如何转发到service的规则，配置模版

ingress通过http和https暴漏集群内部service，给service提供一个外部的url，负载均衡，ssl/tls（https）的能力，实现一个基于域名的负载均衡

ingress如何实现

ingress-controller：具体的实现反向代理和负载均衡的程序，对ingress定义的规则进行解析，根据ingress的配置进行请求的转发

ingress-controller不是k8s自带的组件功能，ingress-controller一个统称
?
nginx ingress controller
traefik都是ingress-controller  都是开源的

ingress资源的定义项

1、定义外部流量的路由规则

2、定义服务的暴漏方式，主机名，访问路径和其他的选项

3、负载均衡（ingress-controller）

ingress-controller的运行方式是pod方式运行集群当中

nginx-ingress-controller

wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/mandatory.yaml

ingress暴漏服务方式

1、deployment+LoadBalancer模式，ingress部署在公有云，会ingress配置文件里面有type，type：LoadBalancer，公有云平台会为个LoadBalancer的service创建一个负载均衡器，绑定一个公网地址，通过域名指向这个公网地址就可以实现集群对外暴漏

2、方式二：Daemonset+hostnetwork+nodeSelector

Daemonsetset 在每个节点都会创建一个pod

hostnetwork pod共享节点主机的网络命名空间，容器内直接使用节点主机的ip+端口，pod中的容器可以直接访问主机上的网络资源

nodeSelecor 根据标签选择部署的节点，nginx-ingress-controller部署的节点

缺点：直接利用节点主机的网络和端口，一个node只能部署一个ingress-controller pod比较适合大并发的生产环境，性能最好的

Daemonset+hostnetwork+nodeSelector实现

修改生成的配置文件mandatory.yaml

.............


apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nginx-ingress-controller
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  #replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/part-of: ingress-nginx
      annotations:
        prometheus.io/port: "10254"
        prometheus.io/scrape: "true"
    spec:
      # wait up to five minutes for the drain of connections
      terminationGracePeriodSeconds: 300
      serviceAccountName: nginx-ingress-serviceaccount
      hostNetwork: true
      nodeSelector:
        test1: "true"
   #     kubernetes.io/os: linux
      containers:
        - name: nginx-ingress-controller
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.30.0
          args:
            - /nginx-ingress-controller
            - --configmap=$(POD_NAMESPACE)/nginx-configuration
.............


把镜像（拖到opt）上传
tar -xf ingree.contro-0.30.0.tar.gz
docker load  -i ingree.contro-0.30.0.tar.gz 

service 的yaml文件
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nfs-pvc
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: nfs-client-storageclass
  resources:
    requests:
      storage: 2Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-app
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.22
        volumeMounts:
        - name: nfs-pvc
          mountPath: /usr/share/nginx/html
      volumes:
      - name: nfs-pvc
        persistentVolumeClaim:
          claimName: nfs-pvc
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-app-svc
spec:
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  selector:
    app: nginx
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nginx-app-ingress
spec:
  rules:
  - host: www.test1.com
    http:
      paths:
      - path: /
        pathType: Prefix
#根据前缀进行匹配 / www.test1.com/  www.test1.com/ www.test1.com /www/www1/www2
        backend:
          service:
            name: nginx-app-svc
            port:
              number: 80


给node节点设置标签
kubectl label nodes node02 test1=true

给node02节点做映射
20.0.0.70 master01
20.0.0.71 node01
20.0.0.72 node02 www.test1.com

3、deployment+NodePort

主要通过nginx-ingress-controller
host-ingress的配置找到pod----controller---请求发到pod
NodePort---controller---ingress----service---pod
NodePort暴漏端口的方式是最简单的方法，NodePort多了一层nat（地址转换），并发量大的对性能会有一定影响，内部都会用NodePort

修改配置文件

生成service-nodePort的yaml文件
wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/provider/baremetal/service-nodeport.yaml

用最原始的生成的mandatory.yaml

修改service的标签
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nfs-pvc1
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: nfs-client-storageclass
  resources:
    requests:
      storage: 2Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-app1
  labels:
    app: nginx2
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx2
  template:
    metadata:
      labels:
        app: nginx2
    spec:
      containers:
      - name: nginx
        image: nginx:1.22
        volumeMounts:
        - name: nfs-pvc
          mountPath: /usr/share/nginx/html
      volumes:
      - name: nfs-pvc
        persistentVolumeClaim:
          claimName: nfs-pvc1
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-app-svc1
spec:
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  selector:
    app: nginx2
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nginx-app-ingress
spec:
  rules:
  - host: www.test2.com
    http:
      paths:
      - path: /
        pathType: Prefix
#根据前缀进行匹配 / www.test1.com/  www.test1.com/ www.test1.com /www/www1/www2
        backend:
          service:
            name: nginx-app-svc1
            port:
              number: 80

生成的service-nodeport.yaml
apiVersion: v1
kind: Service
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  type: NodePort
  ports:
    - name: http
      port: 80
      targetPort: 80
      protocol: TCP
    - name: https
      port: 443
      targetPort: 443
      protocol: TCP
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
#现在执行这个yaml文件，会生成一个service,在ingress-nginx这个命名空间生成一个service，所有的controller的请求都会
#从这个定义的service的nodeport的端口，把请求转发到自定义的service的pod


做映射
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
20.0.0.70 master01
20.0.0.71 node01 www.test2.com
20.0.0.72 node02 www.test1.com

虚拟主机的方式实现http代理

ingress的方式实现：一个ingress可以访问不同的主机

pod1

apiVersion: apps/v1
kind: Deployment
metadata:
  name: deployment1
  labels:
    test: nginx1
spec:
  replicas: 1
  selector:
    matchLabels:
      test: nginx1
  template:
    metadata:
      labels:
        test: nginx1
    spec:
      containers:
      - name: nginx1
        image: nginx:1.22
---
apiVersion: v1
kind: Service
metadata:
  name: svc-1
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  selector:
    test: nginx1

pod2

apiVersion: apps/v1
kind: Deployment
metadata:
  name: deployment2
  labels:
    test: nginx2
spec:
  replicas: 1
  selector:
    matchLabels:
      test: nginx2
  template:
    metadata:
      labels:
        test: nginx2
    spec:
      containers:
      - name: nginx2
        image: nginx:1.22
---
apiVersion: v1
kind: Service
metadata:
  name: svc-2
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  selector:
    test: nginx2
    
pod-ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress1
spec:
  rules:
    - host: www1.test.com
      http:
        paths:
        - path: /
          pathType: Prefix
          backend:
            service:
              name: svc-1
              port:
                number: 80
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress2
spec:
  rules:
    - host: www2.test.com
      http:
        paths:
        - path: /
          pathType: Prefix
          backend:
            service:
              name: svc-2
              port:
                number: 80


做映射
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
20.0.0.70 master01
20.0.0.71 node01 www2.test.com
20.0.0.72 node02 www1.test.com


查看对外访问的端口（service）
kubectl get svc -o wide -n ingress-nginx 
NAME            TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)                      AGE   SELECTOR
ingress-nginx   NodePort   10.96.23.193   <none>        80:30150/TCP,443:30780/TCP   42m   app.kubernetes.io/name=ingress-nginx,app.kubernetes.io/part-of=ingress-nginx