kubernetes 項目實戰（nginx+ php + RDS(mysql)）

我們將會從簡入難一步一步的搭建這個系統，掌握 k8s 搭建項目的思路，主要為理解k8s 的使用，不代表生產環境，因為有更簡潔的方法。

首先我們要編寫 Dockerfile 文件，在本機生成我們需要的基礎鏡像，生產環境下我們可以把鏡像上傳私有倉庫，或者公共倉庫中.

目的：把不經常變動的配置固定下來，可以更好的管理和配置整個項目。

Dockerfile 文件可以參考上個項目，代碼在這里

生成本地nginx 鏡像

[root@k8s nginx]# docker build -t="wpic/nginx:latest" .
Sending build context to Docker daemon  8.192kB
Step 1/5 : FROM nginx
 ---> f6d0b4767a6c
Step 2/5 : MAINTAINER bushaoxun
 ---> Running in b3eff448d1ff
Removing intermediate container b3eff448d1ff
 ---> 3da757f54cea
Step 3/5 : EXPOSE 22 80
 ---> Running in f0e4256ef9e6
Removing intermediate container f0e4256ef9e6
 ---> 1138dec11c30
Step 4/5 : COPY wordpress.conf /etc/nginx/conf.d/default.conf
 ---> 13b4b3b01008
Step 5/5 : COPY nginx.conf /etc/nginx/nginx.conf
 ---> ea0b031273ae
Successfully built ea0b031273ae
Successfully tagged wpic/nginx:latest

生成本地php-fpm 鏡像

docker build -t "wpic/php:7.4-fpm"

構建 Pod 運行 nginx 鏡像

首先我們要構建一個 基於nginx 鏡像的 Pod， yaml 文件如下

apiVersion: v1    # 為 wordpress 項目創建一個獨立的命名空間
kind: Namespace
metadata:
  name: wordpress
---
apiVersion: v1
kind: Pod
metadata:
  name: wordpress
  namespace: wordpress
  labels:
    name: wordpress   # 為 Pod 設置標簽，方便其他資源對象使用標簽選擇器
spec:
  containers:
  - name: wordpress
    image: wpic/nginx:latest
    imagePullPolicy: IfNotPresent  
    ports:
    - name: nginx
      containerPort: 80
      hostPort: 9000  # 映射容器端口到宿主機端口
  restartPolicy: OnFailure

 掛載宿主機目錄到 Pod 中 (實現代碼永久性存儲)

apiVersion: v1
kind: Namespace
metadata:
  name: wordpress
---
apiVersion: v1
kind: Pod
metadata:
  name: wordpress
  namespace: wordpress
  labels:
    name: wordpress
spec:
  containers:
  - name: wordpress
    image: wpic/nginx:latest
    imagePullPolicy: IfNotPresent
    ports:
    - name: nginx
      containerPort: 80
      hostPort: 9000
    volumeMounts: 
    - name: wordpress  # 掛在本地存儲到容器目錄
      mountPath: "/usr/share/nginx/html"
  restartPolicy: OnFailure
  volumes:
  - name: wordpress  # 定義本地儲存
    hostPath:
      path: "/var/www/html"

 添加 php-fpm 容器， 我們使用官方鏡像 php:7.4-fpm

apiVersion: v1
kind: Namespace
metadata:
  name: wordpress
---
apiVersion: v1
kind: Pod
metadata:
  name: wordpress
  namespace: wordpress
  labels:
    name: wordpress
spec:
  containers:
  - name: nginx
    image: wpic/nginx:latest
    imagePullPolicy: IfNotPresent
    ports:
    - name: nginx
      containerPort: 80
      hostPort: 9000
    volumeMounts:
    - name: wordpress
      mountPath: "/usr/share/nginx/html"
  - name: php-fpm
    image: wpic/php:7.4-fpm
    lifecycle:   # 授予 wordpress 讀寫權限
      postStart:
        exec:
          command:
          - "chown"
          - "-R"
          - "www-data.www-data"
          - "/usr/share/nginx/html"
    imagePullPolicy: IfNotPresent
    ports:
    - containerPort: 9000
    volumeMounts:    #必須在容器中掛載，和 nginx 配置有關
    - name: wordpress
      mountPath: "/usr/share/nginx/html"
  restartPolicy: OnFailure
  volumes:
  - name: wordpress
    hostPath:
      path: "/var/www/html"

 以 ConfigMap 的形式把nginx 配置文件掛載到 nginx 容器中 （生產環境中，我們一定要自己生成 特有的 docker 鏡像，固定不常更改的配置文件到鏡像中）

apiVersion: v1
kind: Namespace
metadata:
  name: wordpress
---
apiVersion: v1
kind: Pod
metadata:
  name: wordpress
  namespace: wordpress
  labels:
    name: wordpress
spec:
  containers:
  - name: nginx
    image: wpic/nginx:latest
    imagePullPolicy: IfNotPresent
    ports:
    - name: nginx
      containerPort: 80
      hostPort: 9000
    volumeMounts:
    - name: wordpress
      mountPath: "/usr/share/nginx/html"
    - name: configmap-nginx  # 掛載 nginx 配置文件
      mountPath: /etc/nginx/conf.d
  - name: php-fpm
    image: wpic/php:7.4-fpm
    lifecycle:    # 為 wordpress 授予讀寫的權限
      postStart:
        exec:
          command:
          - "chown"
          - "-R"
          - "www-data.www-data"
          - "/usr/share/nginx/html"
    imagePullPolicy: IfNotPresent
    ports:
    - containerPort: 9000
    volumeMounts:
    - name: wordpress
      mountPath: "/usr/share/nginx/html"
  restartPolicy: OnFailure
  volumes:
  - name: wordpress
    hostPath:
      path: "/var/www/html"
  - name: configmap-nginx
    configMap:       #定義 ConfigMap 為數據卷
      name: nginx
      items:
      - key: wordpress.conf
        path: wordpress.conf

# 在命名空間 wordpress 中創建名字為 ConfigMap 對象， configmap-nginx 是目錄，目錄中存在配置文件 wordpress.conf.
 kubectl create configmap nginx --from-file=configmap-nginx -n wordpress
# wordpress.conf 文件內容如下
 server {
        listen       80;
        server_name  0.0.0.0;
        root   /usr/share/nginx/html;
        index  index.php index.html;

        error_page 404 /404.html;
            location = /40x.html {
        }

        error_page 500 502 503 504 /50x.html;
            location = /50x.html {
        }

        location ~.*\.php$ {
           fastcgi_index index.php;
           try_files $uri =404;
           fastcgi_buffers      32 32K;
           fastcgi_buffer_size  32K;
           fastcgi_pass 127.0.0.1:9000;
           fastcgi_read_timeout 600; 
           #fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
           fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
           include fastcgi_params;
        }

}