Docker教學

安裝

OSX: https://docs.docker.com/docker-for-mac/install/

windows版本的docker建議可以使用kitemantic整合環境

windows: https://kitematic.com/

https://store.docker.com/search?type=edition&offering=community

windows使用kitemantic後點選右下角的DOCKER CLI

以下為Docker執行Redis與Node.js server並分別expose兩個PORT的範例

1.新增package.json

{
  "name": "docker_web_app",
  "version": "1.0.0",
  "description": "Node.js on Docker",
  "author": "First Last <[e-mail]>",
  "main": "server.js",
  "scripts": {
    "start": "node server.js"
  },
  "dependencies": {
    "express": "^4.13.3"
  }
}

2.server.js

'use strict';

const express = require('express');

// Constants
const PORT = 8080;
const HOST = '0.0.0.0';

// App
const app = express();
app.get('/', (req, res) => {
  res.send('Hello world\n');
});

app.listen(PORT, HOST);
console.log(`Running on http://${HOST}:${PORT}`);

3.Dockerfile

FROM node:boron

WORKDIR /usr/src/app

RUN apt-get update && apt-get install -y redis-server

COPY package.json .

RUN npm install

# Bundle app source
COPY . .

EXPOSE 8080 6379
CMD [ "npm", "start" ]

4.

建立image

(-t 為tag 的意思即為這個image的名字)

docker build -t test/node-web-app .

5.

執行image

(意思為把Node.js server之8080port開放給外面電腦的49160，與開放Redis的6379給外面電腦的49161)

開啟瀏覽器localhost:49160即可看到

 docker run -p 49160:8080 49161:6379 test/node-web-app

6.連線到Redis

記得先進去container開啟Redis-server

docker ps

之後會顯示如下

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS
          PORTS                                              NxAMESe
c7b4df8ebffb        test/node-web-app   "npm start"         11 minutes ago      Up 11 minu

然後用exec的方法進入docker的Process 之cli

docker exec -it c7b4df8ebffb /bin/bash

啟動Redis

redis-server

7.之後寫一個Node.js的程式來連Redis

const redis = require('redis')
  RDS_PORT = 49161,
  RDS_HOST = '127.0.0.1',
  client = redis.createClient(RDS_PORT, RDS_HOST,{});

  client.on('ready', (res) => {
    console.log('ready');
  })

把image搬到其他電腦

把最後面參數名字的image(剛才tag名稱)存成 dockerImage 壓縮檔

docker save -o ./dockerImage test/node-web-app

然後把此image壓縮檔移到在別台電腦及可讀取

 docker load -i ./dockerImage

PUSH Image到Docker Hub

1.先到https://hub.docker.com/註冊帳號

2.Create new repository

3.登入

docker login --username=<你的Dockerhub username> --password=<你的docker Hub密碼>

4.查看你要push的image的ID

docker images

5.把ID配上你的repository名稱

docker tag bb38976d03cf yourhubusername/repositoryName

6.推送

docker push yourhubusername/repositoryName

https://ropenscilabs.github.io/r-docker-tutorial/04-Dockerhub.html

減少 Build 後 Image 檔案大小

使用 multistage build

https://docs.docker.com/develop/develop-images/multistage-build/