K8S-应用访问

1 service对象定位

2 Service 实践

手工创建Service

根据应用部署资源对象，创建SVC对象
kubectl expose deployment nginx --port=80 --type=NodePort

yaml方式创建Service

nginx-web的service资源清单文件
apiVersion: v1
kind: Service
metadata:
  name: sswang-nginx-web
  labels:
    app: nginx-web
spec:
  type: NodePort
  selector:
    app: nginx-web
  ports:
    - protocol: TCP
      name: http
      port: 80
      targetPort: 80
      nodePort: 31080

tomcat-web的service资源清单文件
apiVersion: v1
kind: Service
metadata:
  name: sswang-tomcat-web
  labels:
    app: tomcat-web
spec:
  type: NodePort
  selector:
    app: tomcat
  ports:
    - protocol: TCP
      name: http
      port: 8080
      targetPort: 8080
      nodePort: 31880

3 外部Service

部署外部mysql环境

准备软件源
]# cat /etc/yum.repos.d/MariaDB.repo
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.3/centos7-amd64
gpgcheck=0

更新系统软件包：
yum makecache fast

安装 MySQL 服务器
yum install mariadb-server mariadb -y 

设置 MySQL 服务在启动时自动启动
systemctl start mariadb.service
systemctl enable mariadb.service

开启 MySQL 服务器远程访问能力
]# vim /etc/my.cnf.d/server.cnf
[mysqld]
bind-address = 0.0.0.0

重启 MySQL 服务使配置生效
systemctl restart mariadb.service

配置远程主机登录权限
mysql -uroot -p123456 -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;"
mysql -uroot -p123456 -e "FLUSH PRIVILEGES;"

主库上创建数据库
]# mysql -uroot -p123456 -e "
CREATE DATABASE bookinfo default charset utf8 collate utf8_general_ci;
USE bookinfo;
CREATE TABLE book_info (
  id INT AUTO_INCREMENT PRIMARY KEY,
  book_name VARCHAR(100),
  author VARCHAR(100),
  date_of_issue DATE,
  isDelete BOOLEAN
);
INSERT INTO book_info (book_name, author, date_of_issue, isDelete) VALUES
  ('Book 1', 'Author 1', '2022-01-01', FALSE),
  ('Book 2', 'Author 2', '2022-02-01', FALSE),
  ('Book 3', 'Author 3', '2022-03-01', TRUE);
"

定制资源清单文件

apiVersion: v1
kind: Namespace
metadata:
  name: external-ns
---
apiVersion: v1
kind: Endpoints
metadata:
  name: ex-mysql
  namespace: external-ns
subsets:
  - addresses:
      - ip: 10.0.0.18
    ports:
      - port: 3306
---
apiVersion: v1
kind: Service
metadata:
  name: ex-mysql
  namespace: external-ns
spec:
  type: ClusterIP
  ports:
  - port: 3306
    targetPort: 3306
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: bookinfo
  namespace: external-ns
spec:
  replicas: 1
  selector:
    matchLabels:
      app: flask-bookinfo
  template:
    metadata:
      labels:
        app: flask-bookinfo
    spec:
      containers:
        - name: flask-bookinfo
          image: kubernetes-register.sswang.com/sswang/flask_bookinfo:2.3.2
          imagePullPolicy: Always
          ports:
            - containerPort: 5000
          env:
            - name: DB_HOST
              value: "ex-mysql"
            - name: DB_USER
              value: "root"
            - name: DB_PASSWORD
              value: "123456"
            - name: DB_DATABASE
              value: "bookinfo"