K8s笔记-使用 Service 把前端连接到后端

1 配置configMap

1.1 配置cm

[root@k8s-master ~]# kubectl exec -it nginx-deploy-78d8bf4fd7-2xtd2 -n test -- sh -c "cat /etc/nginx/nginx.conf"
[root@k8s-master ~]# kubectl exec -it nginx-deploy-78d8bf4fd7-2xtd2 -n test -- sh -c "cat /usr/share/nginx/html/index.html"
# 在本地创建一个nginx.conf的配置文件
vi /k8s-test/subpath/nginx.conf
vi /k8s-test/subpath/index.html
vi /k8s-test/subpath/nginx-front.html
# 使用nginx.conf创建一个configmap
[root@k8s-master subpath]# kubectl create configmap nginx-conf-cm --from-file=/k8s-test/subpath/nginx.conf
[root@k8s-master subpath]# kubectl create configmap nginx-front-cm --from-file=/k8s-test/subpath/nginx-front.conf
[root@k8s-master subpath]# kubectl create configmap nginx-index-cm --from-file=/k8s-test/subpath/index.html

1.2 文件内容

[root@k8s-master subpath]# cat index.html 
<h1>Welcome to nginx from backend!</h1>
###################################################################################################
[root@k8s-master subpath]# cat nginx.conf 
user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  10249;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    include /etc/nginx/conf.d/*.conf;
}

########################################################################
[root@k8s-master subpath]# cat nginx-front.conf 
# Backend 是 nginx 的内部标识符，用于命名以下特定的 upstream
upstream Backend {
    # hello 是 Kubernetes 中的后端服务所使用的内部 DNS 名称
    server nginx-backend;
}

server {
    listen 80;

    location / {
        # 以下语句将流量通过代理方式转发到名为 Backend 的上游
        proxy_pass http://Backend;
    }
}

2 创建后端

2.1 配置文件

[root@k8s-master nginx]# cat nginx-depoly-backend.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.16.1    
        ports:
        - containerPort: 80
        volumeMounts:
        - name: nginx-index
          mountPath: 'usr/share/nginx/html/index.html'
          subPath: usr/share/nginx/html/index.html
      volumes:
      - name: nginx-index
        configMap:
          name: nginx-index-cm
          items:
          - key: index.html
            path: usr/share/nginx/html/index.html
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-backend
  labels:
    app: nginx
spec:
  selector:
    app: nginx
  ports:
  - port: 80
    targetPort: 80

3 创建前端

3.1 配置文件

[root@k8s-master nginx]# cat nginx-depoly-frontend.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-frontend
  labels:
    app: nginx-frontend
spec:
  selector:
    matchLabels:
      app: nginx-frontend
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx-frontend
    spec:
      containers:
      - name: nginx-frontend
        image: nginx:1.16.1    
        ports:
        - containerPort: 80
        volumeMounts: # 挂载数据卷
        - name: nginx-conf # 要挂载数据卷的名称
          mountPath: '/etc/nginx/nginx.conf' # 数据卷的挂载路径
          subPath: etc/ngxin/nginx.conf
        - name: nginx-front # 要挂载数据卷的名称
          mountPath: '/etc/nginx/conf.d/default.conf' # 数据卷的挂载路径
          subPath: etc/nginx/conf.d/default.conf
      volumes: # 数据卷的定义
      - name: nginx-conf # 数据卷的名称
        configMap: # 数据卷类型为 configmap 
          name: nginx-conf-cm # 使用的configmap的名字
          items: # 对configMap中的key进行映射，如果不指定，默认会将configmap中所有key全部转换为一个同名的文件
          - key: nginx.conf # 指定挂载那个key
            path: etc/ngxin/nginx.conf # 挂载后该key重命名为什么名字
      - name: nginx-front # 数据卷的名称
        configMap: # 数据卷类型为 configmap 
          name: nginx-front-cm # 使用的configmap的名字
          items: # 对configMap中的key进行映射，如果不指定，默认会将configmap中所有key全部转换为一个同名的文件
          - key: nginx-front.conf # 指定挂载那个key
            path: etc/nginx/conf.d/default.conf # 挂载后该key重命名为什么名字
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-frontend
spec:
  selector:
    app: nginx-frontend
  ports:
  - protocol: "TCP"
    port: 80
    targetPort: 80
  type: NodePort

4 测试

[root@k8s-node1 ~]# kubectl run -it test --image=busybox:1.28 --rm --restart=Never -- /bin/sh
# wget http://nginx-frontend
Connecting to nginx-frontend (10.105.228.85:80)
index.html           100% |****************************************************************************************************************************|    40   0:00:00 ETA
/ # cat index.html
<h1>Welcome to nginx from backend!</h1>