Kubernetes之Ingress详解与示例

2021-07-31 21:13:35

1.Ingress概述

Ingress 是对集群中服务的外部访问进行管理的 API 对象，典型的访问方式是 HTTP和HTTPS。
Ingress 可以提供负载均衡、SSL 和基于名称的虚拟托管。
必须具有 ingress 控制器【例如 ingress-nginx】才能满足 Ingress 的要求。仅创建 Ingress 资源无效。

1.1Ingress 是什么

Ingress 公开了从集群外部到集群内 services 的 HTTP 和 HTTPS 路由。流量路由由 Ingress 资源上定义的规则控制。

1  internet
2      |
3 [ Ingress ]
4 --|-----|--
5 [ Services ]

可以将 Ingress 配置为提供服务外部可访问的 URL、负载均衡流量、 SSL / TLS，以及提供基于名称的虚拟主机。Ingress 控制器通常负责通过负载均衡器来实现 Ingress，尽管它也可以配置边缘路由器或其他前端来帮助处理流量。

Ingress 不会公开任意端口或协议。若将 HTTP 和 HTTPS 以外的服务公开到 Internet 时，通常使用 Service.Type=NodePort 或者 Service.Type=LoadBalancer 类型的服务。

以Nginx Ingress为例，图如下

2.Ingress示例

2.1架构图

2.2部署Ingress-Nginx

1）镜像下载与重命名

docker pull registry.cn-beijing.aliyuncs.com/google_registry/nginx-ingress-controller:0.30.0
docker tag 89ccad40ce8e quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.30.0
docker rmi  registry.cn-beijing.aliyuncs.com/google_registry/nginx-ingress-controller:0.30.0

2）ingress-nginx的yaml文件修改后并启动

# 当前目录
[root@k8s-master ingress]# pwd
/root/k8s_practice/ingress
# 获取NGINX: 0.30.0
[root@k8s-master ingress]# wget https://github.com/kubernetes/ingress-nginx/archive/nginx-0.30.0.tar.gz
[root@k8s-master ingress]# tar xf nginx-0.30.0.tar.gz
# yaml文件在下载包中的位置：ingress-nginx-nginx-0.30.0/deploy/static/mandatory.yaml
[root@k8s-master ingress]# cp -a ingress-nginx-nginx-0.30.0/deploy/static/mandatory.yaml ./
[root@k8s-master ingress]#
# yaml文件配置修改
[root@k8s-master ingress]# vim mandatory.yaml
………………
apiVersion: apps/v1
kind: DaemonSet   # 从Deployment改为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   # 注释掉
………………
      nodeSelector:
        kubernetes.io/hostname: k8s-master   # 修改处
      # 如下几行为新加行  作用【允许在master节点运行】
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
………………
          ports:
            - name: http
              containerPort: 80
              hostPort: 80    # 添加处【可在宿主机通过该端口访问Pod】
              protocol: TCP
            - name: https
              containerPort: 443
              hostPort: 443   # 添加处【可在宿主机通过该端口访问Pod】
              protocol: TCP
………………
[root@k8s-master ingress]#
[root@k8s-master ingress]# kubectl apply -f mandatory.yaml
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-role created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created
daemonset.apps/nginx-ingress-controller created
limitrange/ingress-nginx created
[root@k8s-master ingress]# kubectl get ds -n ingress-nginx -o wide
NAME                       DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                       AGE     CONTAINERS                 IMAGES                                                                  SELECTOR
nginx-ingress-controller   1         1         1       1            1           kubernetes.io/hostname=k8s-master   9m47s   nginx-ingress-controller   quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.30.0   app.kubernetes.io/name=ingress-nginx,app.kubernetes.io/part-of=ingress-nginx
[root@k8s-master ingress]#
[root@k8s-master ingress]# kubectl get pod -n ingress-nginx -o wide
NAME                             READY   STATUS    RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES
nginx-ingress-controller-rrbh9   1/1     Running   0          9m55s   10.244.0.46   k8s-master   <none>           <none>

2.3deply_service1的yaml信息

1）yaml文件

[root@k8s-master ingress]# pwd
/root/k8s_practice/ingress
[root@k8s-master ingress]# cat deply_service1.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deploy1
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
      release: v1
  template:
    metadata:
      labels:
        app: myapp
        release: v1
        env: test
    spec:
      containers:
      - name: myapp
        image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: myapp-clusterip1
  namespace: default
spec:
  type: ClusterIP  # 默认类型
  selector:
    app: myapp
    release: v1
  ports:
  - name: http
    port: 80
    targetPort: 80

2）启动Deployment和Service

[root@k8s-master ingress]# kubectl apply -f deply_service1.yaml 
deployment.apps/myapp-deploy1 created
service/myapp-clusterip1 created

3）查看Deploy状态和信息

[root@k8s-master ingress]# kubectl get deploy,rs,po -o wide --show-labels
NAME                            READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES                                                      SELECTOR               LABELS
deployment.apps/myapp-deploy1   3/3     3            3           2m47s   myapp        registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,release=v1   <none>

NAME                                       DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                                                      SELECTOR                                            LABELS
replicaset.apps/myapp-deploy1-6c468d6b6c   3         3         3       2m47s   myapp        registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=6c468d6b6c,release=v1   app=myapp,env=test,pod-template-hash=6c468d6b6c,release=v1

NAME                                 READY   STATUS    RESTARTS   AGE     IP           NODE        NOMINATED NODE   READINESS GATES   LABELS
pod/myapp-deploy1-6c468d6b6c-fbcln   1/1     Running   0          2m47s   10.244.2.5   k8s-node2   <none>           <none>            app=myapp,env=test,pod-template-hash=6c468d6b6c,release=v1
pod/myapp-deploy1-6c468d6b6c-shz6z   1/1     Running   0          2m47s   10.244.2.6   k8s-node2   <none>           <none>            app=myapp,env=test,pod-template-hash=6c468d6b6c,release=v1
pod/myapp-deploy1-6c468d6b6c-zqn7b   1/1     Running   0          2m47s   10.244.1.6   k8s-node1   <none>           <none>            app=myapp,env=test,pod-template-hash=6c468d6b6c,release=v1

4）curl访问pod

[root@k8s-master ingress]# curl 10.244.2.5
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-master ingress]# curl 10.244.2.6
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-master ingress]# curl 10.244.1.6
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

5）查看Service状态和信息

1 [root@k8s-master ingress]# kubectl get svc -o wide
2 NAME               TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE     SELECTOR
3 kubernetes         ClusterIP   10.96.0.1       <none>        443/TCP   19d     <none>
4 myapp-clusterip1   ClusterIP   10.104.146.14   <none>        80/TCP    5m38s   app=myapp,release=v1

6）curl访问svc

[root@k8s-master ingress]# kubectl get svc -o wide
NAME               TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE     SELECTOR
kubernetes         ClusterIP   10.96.0.1        <none>        443/TCP   6h48m   <none>
myapp-clusterip1   ClusterIP   10.103.139.138   <none>        80/TCP    4m9s    app=myapp,release=v1
[root@k8s-master ingress]# curl 10.103.139.138
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-master ingress]# curl 10.103.139.138/hostname.html
myapp-deploy1-6c468d6b6c-shz6z
[root@k8s-master ingress]# curl 10.103.139.138/hostname.html
myapp-deploy1-6c468d6b6c-zqn7b
[root@k8s-master ingress]# curl 10.103.139.138/hostname.html
myapp-deploy1-6c468d6b6c-fbcln

2.4deply_service2的yaml信息

1）yaml文件

[root@k8s-master ingress]# pwd
/root/k8s_practice/ingress
[root@k8s-master ingress]# cat deply_service2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deploy2
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
      release: v2
  template:
    metadata:
      labels:
        app: myapp
        release: v2
        env: test
    spec:
      containers:
      - name: myapp
        image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v2
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: myapp-clusterip2
  namespace: default
spec:
  type: ClusterIP  # 默认类型
  selector:
    app: myapp
    release: v2
  ports:
  - name: http
    port: 80
    targetPort: 80

2）启动Deployment和Service

[root@k8s-master ingress]# kubectl apply -f deply_service2.yaml 
deployment.apps/myapp-deploy2 created
service/myapp-clusterip2 created

3）查看Deploy状态和信息

[root@k8s-master ingress]# kubectl get deploy,rs,po -o wide --show-labels -l "release=v2"
NAME                                       DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR                                            LABELS
replicaset.apps/myapp-deploy2-5fffdcccd5   3         3         3       50s   myapp        registry.cn-beijing.aliyuncs.com/google_registry/myapp:v2   app=myapp,pod-template-hash=5fffdcccd5,release=v2   app=myapp,env=test,pod-template-hash=5fffdcccd5,release=v2

NAME                                 READY   STATUS    RESTARTS   AGE   IP           NODE        NOMINATED NODE   READINESS GATES   LABELS
pod/myapp-deploy2-5fffdcccd5-4qn5c   1/1     Running   0          50s   10.244.2.7   k8s-node2   <none>           <none>            app=myapp,env=test,pod-template-hash=5fffdcccd5,release=v2
pod/myapp-deploy2-5fffdcccd5-gvcqp   1/1     Running   0          50s   10.244.1.8   k8s-node1   <none>           <none>            app=myapp,env=test,pod-template-hash=5fffdcccd5,release=v2
pod/myapp-deploy2-5fffdcccd5-pbqqp   1/1     Running   0          50s   10.244.1.7   k8s-node1   <none>           <none>            app=myapp,env=test,pod-template-hash=5fffdcccd5,release=v2

4）查看Service状态和信息

[root@k8s-master ingress]# kubectl get svc -o wide
NAME               TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE     SELECTOR
kubernetes         ClusterIP   10.96.0.1        <none>        443/TCP   6h51m   <none>
myapp-clusterip1   ClusterIP   10.103.139.138   <none>        80/TCP    7m36s   app=myapp,release=v1
myapp-clusterip2   ClusterIP   10.107.114.166   <none>        80/TCP    114s    app=myapp,release=v2

5）curl访问svc

[root@k8s-master ingress]# curl 10.107.114.166
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
[root@k8s-master ingress]# curl 10.107.114.166/hostname.html
myapp-deploy2-5fffdcccd5-pbqqp
[root@k8s-master ingress]# curl 10.107.114.166/hostname.html
myapp-deploy2-5fffdcccd5-4qn5c
[root@k8s-master ingress]# curl 10.107.114.166/hostname.html
myapp-deploy2-5fffdcccd5-gvcqp

2.5Ingress HTTP代理访问

1）yaml文件【由于自建的service在默认default名称空间，因此这里也是default名称空间】

[root@k8s-master ingress]# pwd
/root/k8s_practice/ingress
[root@k8s-master ingress]# cat ingress-http.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: nginx-http
  namespace: default
spec:
  rules:
    - host: www.zhangtest.com
      http:
        paths:
        - path: /
          backend:
            serviceName: myapp-clusterip1
            servicePort: 80
    - host: blog.zhangtest.com
      http:
        paths:
        - path: /
          backend:
            serviceName: myapp-clusterip2
            servicePort: 80

2）启动ingress http并查看状态

[root@k8s-master ingress]# kubectl apply -f ingress-http.yaml
Warning: networking.k8s.io/v1beta1 Ingress is deprecated in v1.19+, unavailable in v1.22+; use networking.k8s.io/v1 Ingress
ingress.networking.k8s.io/nginx-http created
[root@k8s-master ingress]# kubectl get ingress -o wide
Warning: extensions/v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io/v1 Ingress
NAME         CLASS    HOSTS                                  ADDRESS   PORTS   AGE
nginx-http   <none>   www.zhangtest.com,blog.zhangtest.com             80      9s

3）查看nginx配置文件

[root@k8s-master ~]# kubectl get pod -A | grep ‘ingre‘
ingress-nginx          nginx-ingress-controller-rrbh9               1/1     Running   0          27m
[root@k8s-master ~]#
[root@k8s-master ~]# kubectl exec -it -n ingress-nginx nginx-ingress-controller-rrbh9 bash
bash-5.0$ cat /etc/nginx/nginx.conf
…………
##### 可见server www.zhangtest.com 和 server blog.zhangtest.com的配置

4）hosts文件修改，添加如下信息

[root@k8s-master ingress]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.3.104.51 k8s-master
10.3.104.52 k8s-node1
10.3.104.56 k8s-node2
185.199.108.133 raw.githubusercontent.com
10.3.104.51 www.zhangtest.com  blog.zhangtest.com
[root@k8s-master ingress]# curl www.zhangtest.com 
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-master ingress]# curl blog.zhangtest.com
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>

2.6Ingress HTTPS代理访问

1）ssl证书创建

[root@k8s-master cert]# pwd
/root/k8s_practice/ingress/cert
[root@k8s-master cert]# openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/C=CN/ST=BJ/L=BeiJing/O=BTC/OU=MOST/CN=zhang/emailAddress=ca@test.com"
Generating a 2048 bit RSA private key
......................................................+++
........................+++
writing new private key to ‘tls.key‘
-----
[root@k8s-master cert]# kubectl create secret tls tls-secret --key tls.key --cert tls.crt
secret/tls-secret created

2）创建ingress https

yaml文件【由于自建的service在默认default名称空间，因此这里也是default名称空间】

[root@k8s-master ingress]# pwd
/root/k8s_practice/ingress
[root@k8s-master ingress]# cat ingress-https.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: nginx-https
  namespace: default
spec:
  tls:
    - hosts:
      - www.zhangtest.com
      - blog.zhangtest.com
      secretName: tls-secret
  rules:
    - host: www.zhangtest.com
      http:
        paths:
        - path: /
          backend:
            serviceName: myapp-clusterip1
            servicePort: 80
    - host: blog.zhangtest.com
      http:
        paths:
        - path: /
          backend:
            serviceName: myapp-clusterip2
            servicePort: 80

3）启动ingress https并查看状态

[root@k8s-master ingress]# kubectl apply -f ingress-https.yaml
ingress.networking.k8s.io/nginx-https created
[root@k8s-master ingress]#
[root@k8s-master ingress]# kubectl get ingress -o wide
NAME          HOSTS                                  ADDRESS   PORTS     AGE
nginx-https   www.zhangtest.com,blog.zhangtest.com             80, 443   8s