使用kompose 快速转换dokcer-compose 文件为k8s deploy 文件

kompose 是一个不错的快速转换docker-compose 文件为k8s 部署yaml文件的工具，使用次工具我们
可以将简单的docker-compose文件，转换为复杂的yaml文件，对于使用者来说可以减少yaml的错误，
同时可以实现docker-compose 向k8s 的快速迁移

简单docker-compose 文件

version: '3'
services:
  gogs-service:
    image: gogs/gogs
    restart: always
    ports:
      - "10022:22"
      - "10080:3000"
    volumes:
      - ./data/gogs:/data
    depends_on:
      - mysql-gogs
  mysql-gogs:
    image: mysql:5.7.16
    restart: 'always'
    volumes:
      - ./gogs/mysql:/var/lib/mysql
    ports:
      - 3308:3306
    command: --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
    environment:
      MYSQL_ROOT_PASSWORD: dalongrong
      MYSQL_DATABASE: gogs
      MYSQL_USER: gogs
      MYSQL_PASSWORD: dalongrong
      TZ: Asia/Shanghai

说明，这是一个gogs git 工具的安装，docker-compose 文件不是很复杂

安装kompose

brew install kompose

生成k8s yaml 部署文件

kompose convert

效果如下，文件很简单，包含了deploy 以及pvc 的定义，ingress 是我自己添加的

生成的deploy（gogs）

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    kompose.cmd: kompose convert
    kompose.version: 1.17.0 ()
  creationTimestamp: null
  labels:
    io.kompose.service: gogs-service
  name: gogs-service
spec:
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: gogs-service
    spec:
      containers:
      - image: gogs/gogs
        name: gogs-service
        ports:
        - containerPort: 22
        - containerPort: 3000
        resources: {}
        volumeMounts:
        - mountPath: /data
          name: gogs-service-claim0
      restartPolicy: Always
      volumes:
      - name: gogs-service-claim0
        persistentVolumeClaim:
          claimName: gogs-service-claim0
status: {}

service

apiVersion: v1
kind: Service
metadata:
  annotations:
    kompose.cmd: kompose convert
    kompose.version: 1.17.0 ()
  creationTimestamp: null
  labels:
    io.kompose.service: gogs-service
  name: gogs-service
spec:
  ports:
  - name: "10022"
    port: 10022
    targetPort: 22
  - name: "10080"
    port: 10080
    targetPort: 3000
  selector:
    io.kompose.service: gogs-service
status:
  loadBalancer: {}

说明，mysql 运行需要修改下,使用init container 删除文件夹

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    kompose.cmd: kompose convert
    kompose.version: 1.17.0 ()
  creationTimestamp: null
  labels:
    io.kompose.service: mysql-gogs
  name: mysql-gogs
spec:
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: mysql-gogs
    spec:
      initContainers:
      - name: "remove-lost-found"
        image: "busybox:1.25.0"
        command: ["rm", "-fr", "/var/lib/mysql/lost+found"]
        volumeMounts:
        - name: mysql-gogs-claim0
          mountPath: /var/lib/mysql
      containers:
      - args:
        - --character-set-server=utf8mb4
        - --collation-server=utf8mb4_unicode_ci
        env:
        - name: MYSQL_DATABASE
          value: gogs
        - name: MYSQL_PASSWORD
          value: dalongrong
        - name: MYSQL_ROOT_PASSWORD
          value: dalongrong
        - name: MYSQL_USER
          value: gogs
        - name: TZ
          value: Asia/Shanghai
        image: mysql:5.7.16
        name: mysql-gogs
        ports:
        - containerPort: 3306
        resources: {}
        volumeMounts:
        - mountPath: /var/lib/mysql
          name: mysql-gogs-claim0
      restartPolicy: Always
      volumes:
      - name: mysql-gogs-claim0
        persistentVolumeClaim:
          claimName: mysql-gogs-claim0
status: {}

说明

使用起来还是比较方便的，可以减少好多代码，目前来说，k8s api 的支持感觉不是很好，而且还有一些bug，但是不影响
使用，结合这个工具，我们可以快速的向k8s应用迁移

参考架构图

参考资料

https://github.com/kubernetes/kompose/