Pod

综合实验：构建 wordpreess

1. 创建 pod-mysql 数据库

2. 创建 pod-wordpress 博客

参考步骤：

# 创建 pod-mysql 数据库
[root@master30 ~]# kubectl run wordpress-db --image=mysql --image-pull-policy IfNotPresent --env MYSQL_ROOT_PASSWORD=123

# 创建 pod-wordpress 博客
[root@master30 ~]# kubectl run wordpress-app --image=wordpress --image-pull-policy IfNotPresent

# 实现集群外访问集群内pod
[root@master30 ~]# kubectl port-forward pod/wordpress-app --address 10.1.8.30 8080:80
# 该命令窗口不要关闭

# 查看 IP
[root@master30 ~]# kubectl get pods -o wide | awk '{print $1" "$6}'
NAME IP
wordpress-app 10.224.113.135
wordpress-db 10.224.19.5

# 创建数据库
[root@master30 ~]# mysql -uroot -p123 -h 10.224.19.5
mysql> create database wordpress;
mysql> create user wordpress identified by '123';
mysql> grant all privileges on wordpress.* to wordpress;
mysql> flush privileges;
mysql> exit

访问web页面 http://10.1.8.30:8080，配置站点。

多容器 pod

示例文件：blog.yaml

[root@master30 ~]# vim pod-blog.yaml
apiVersion: v1
kind: Pod
metadata:
  name: bbs
  labels:
    run: bbs
spec:
  containers:
  - image: hub.laoma.cloud/library/mysql:latest
    imagePullPolicy: IfNotPresent
    name: mysql
    env:
    - name: MYSQL_ROOT_PASSWORD
      value: "123"
    - name: MYSQL_USER
      value: tom
    - name: MYSQL_PASSWORD
      value: "123"
    - name: MYSQL_DATABASE
      value: bbs
    ports:
    - containerPort: 3306
      name: mysql
      protocol: TCP
  - image: hub.laoma.cloud/library/wordpress:latest
    imagePullPolicy: IfNotPresent
    name: wordpress
    env:
    - name: WORDPRESS_DB_USER
      value: tom
    - name: WORDPRESS_DB_PASSWORD
      value: "123"
    - name: WORDPRESS_DB_NAME
      value: bbs
    - name: WORDPRESS_DB_HOST
      value: 127.0.0.1
    ports:
    - containerPort: 80
      name: wordpress
      protocol: TCP
      hostPort: 80
[root@master30 ~]# kubectl apply -f pod-blog.yaml

# 查看 pod 运行节点
[root@master30 ~]# kubectl get pods -o wide
NAME   READY   STATUS    RESTARTS   AGE   IP              NODE               NOMINATED NODE   READINESS GATES
bbs    2/2     Running   0          10m   10.224.225.68   worker32.laoma.cloud   <none>           <none>

# 多容器pod中执行命令，通过-c指定容器
[root@master30 ~]# kubectl exec bbs -c wordpress -- hostname
bbs
[root@master30 ~]# kubectl cp /etc/hosts bbs:/new-hosts -c wordpress
[root@master30 ~]# kubectl exec bbs -c wordpress -- ls /new-hosts
/new-hosts

数据库访问测试

[root@master30 ~]# kubectl exec -it bbs -c mysql -- mysql -utom -p123
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

Kubernetes Volume

Volume 类型

• emptyDir

• hostPath

• nfs

• persistentVolumeClaim

Kubernetes Configure

ConfigMap

综合案例：haproxy+web

[root@master30 ~]# mkdir web && cd web
root@master30:~/web# kubectl create cm webapp-1 --from-literal=index.html="hello webapp-1" --from-literal=error.html="sorry, error."
root@master30:~/web# vim pod-webapp-1.yaml

apiVersion: v1
kind: Pod
metadata:
  name: webapp-1
spec:
  containers:
  - name: nginx
    image: hub.laoma.cloud/library/nginx:latest
    imagePullPolicy: IfNotPresent
    volumeMounts:
    - name: config
      mountPath: "/usr/share/nginx/html"
      readOnly: true
  volumes:
  - name: config
    configMap:
      name: webapp-1

root@master30:~/web# kubectl apply -f pod-webapp-1.yaml

root@master30:~/web# kubectl create cm webapp-2 --from-literal=index.html="hello webapp-2" --from-literal=error.html="sorry, error."
root@master30:~/web# vim pod-webapp-2.yaml

apiVersion: v1
kind: Pod
metadata:
  name: webapp-2
spec:
  containers:
  - name: nginx
    image: hub.laoma.cloud/library/nginx:latest
    imagePullPolicy: IfNotPresent
    volumeMounts:
    - name: config
      mountPath: "/usr/share/nginx/html"
      readOnly: true
  volumes:
  - name: config
    configMap:
      name: webapp-2

root@master30:~/web# kubectl apply -f pod-webapp-2.yaml

# 获取pod ip地址
root@master30:~/web# kubectl get pods -o wide
NAME	   READY   STATUS    RESTARTS   AGE   IP              NODE                NOMINATED NODE   READINESS GATES
webapp-1   1/1     Running   0          63m   10.224.84.80    worker1.laoma.fun   <none>           <none>
webapp-2   1/1     Running   0          63m   10.224.149.25   worker2.laoma.fun   <none>           <none>

# haproxy内容如下：
root@master30:~/web# vim haproxy.cfg

global
    daemon
    maxconn 256

defaults
    mode http
    timeout connect 5000ms
    timeout client 50000ms
    timeout server 50000ms

frontend http-in
    bind *:8080
    default_backend servers

backend servers
    server  app1 10.224.84.80:80 check
    server  app2 10.224.149.25:80 check

# 创建haproxy.cfg configmap
root@master30:~/web# kubectl create cm haproxy.cfg --from-file=haproxy.cfg=./haproxy.cfg

# 创建pod haproxy
root@master30:~/web# vim pod-haproxy.yaml

---
apiVersion: v1
kind: Pod
metadata:
  name: haproxy
spec:
  containers:
  - name: haproxy
    image: hub.laoma.cloud/library/haproxy:3.4
    imagePullPolicy: IfNotPresent
    securityContext:
      allowPrivilegeEscalation: true
    volumeMounts:
    - name: config
      mountPath: "/usr/local/etc/haproxy"
      readOnly: true
  volumes:
  - name: config
    configMap:
      name: haproxy.cfg

root@master30:~/web# kubectl apply -f pod-haproxy.yaml

# 验证
root@master30:~/web# kubectl get pods haproxy -o wide
NAME      READY   STATUS    RESTARTS   AGE   IP              NODE                  NOMINATED NODE   READINESS GATES
haproxy   1/1     Running   0          33s   10.224.149.35   worker32.laoma.cloud   <none>           <none>


[root@master30 ~]# curl http://10.224.149.35:8080
hello webapp-1
[root@master30 ~]# curl http://10.224.149.35:8080
hello webapp-2

Secret

Secret 类型

• generic：定义键值对，对变量值加密，类型为Opaque。

• docker-registry：用于访问registry仓库的凭据，类型kubernetes.io/dockerconfigjson。

• tls：保存TLS公钥和私钥，类型为Opaque。