Docker入门
2018-10-17 本文已影响24人
Hey_Shaw
Linux安装Docker
安装docker本身
$ sudo wget -qO- https://get.docker.com/ | sh
-q：让wget输出不要过多
-O-：把wget的输出直接输出到标准输出，而不是输出到文件，管道技术交给sh执行
运行非root用户运行docker
$ sudo usermod -aG docker imooc
把用户加到docker用户组中，使指定用户获取执行docker权限
启动docker服务
$ systemctl start docker.service
设置开机启动
$ sudo systemctl enable docker
docker架构介绍
实战
$ docker run ubuntu echo hello docker
运行nginx
$ docker run -p 8080:80 -d nginx #将docker容器的80端口映射到宿主机8080端口
访问：宿主机ip:8080
定制化自己的nginx页面
$ cat index.html
<html>
<h1>Docker is fun!</h1>
</html>
$ docker ps # 查看运行镜像，获取镜像ID
$ docker cp index.html 653c6d248e5a://usr/share/nginx/html
$ docker stop 653c6d248e5a # 停止运行的镜像
$ docker run -p 8080:80 -d nginx # 原来设定的网页被还原
$ docker cp index.html 58cf1b4ef86b://usr/share/nginx/html
$ docker commit -m 'fun' 58cf1b4ef86b nginx-fun # 保存自定义，生成新的镜像nginx-fun
$ docker rmi 1696742493b7 # 删除镜像
$ docker ps -a # 显示所有运行过的镜像
$ docker rm 5e23511ac629 653c6d248e5a # 删除运行过的镜像历史
命令小结
| 命令 | 用途 |
|---|---|
| docker pull | 获取image |
| docker build | 创建image |
| docker images | 列出image |
| docker run | 运行container |
| docker ps | 列出container |
| docker rm | 删除container |
| docker rmi | 删除image |
| docker cp | 在host和container之间拷贝文件 |
| docker commit | 保存改动为新的image |
Dockerfile
touch Dockerfile # 新建Dockerfile
FROM alpine:latest
MAINTAINER jack
CMD echo "Hello Docker!"
构建新的image
$ docker build -t hello_docker .
Sending build context to Docker daemon 2.048kB
Step 1/3 : FROM alpine:latest
latest: Pulling from library/alpine
4fe2ade4980c: Pull complete
Digest: sha256:621c2f39f8133acb8e64023a94dbdf0d5ca81896102b9e57c0dc184cadaf5528
Status: Downloaded newer image for alpine:latest
---> 196d12cf6ab1
Step 2/3 : MAINTAINER jack
---> Running in 0bf9be49775b
Removing intermediate container 0bf9be49775b
---> 2752ef8ca6a2
Step 3/3 : CMD echo "Hello Docker!"
---> Running in 5aa61e2dcc24
Removing intermediate container 5aa61e2dcc24
---> 9feb05314694
Successfully built 9feb05314694
Successfully tagged hello_docker:latest
运行镜像
$ docker run hello_docker
Hello Docker!
Dockerfile实战
FROM ubuntu
MAINTAINER jack
RUN sed -i 's/archive.ubuntu.com/mirrors.ustc.edu.cn/g' /etc/apt/sources.list # 替换archive.ubuntu.com为mirrors.ustc.edu.cn，加速
RUN apt-get update
RUN apt-get install -y nginx
COPY index.html /var/www/html
ENTRYPOINT ["/usr/sbin/nginx","-g","daemon off;"]
EXPOSE 80
自定义新建index.html
执行下列命令
docker build -t jack/hello_nginx . # 构建镜像
docker run -d -p 80:80 jack/hello_nginx # 启动镜像
docker stop jack/hello_nginx # 停止镜像
Dockerfile语法
| 命令 | 用途 |
|---|---|
| FROM | base image |
| RUN | 执行命令 |
| ADD | 添加文件 |
| COPY | 拷贝文件 |
| CMD | 执行命令 |
| EXPOSE | 暴露端口 |
| WORKDIR | 指定路径 |
| MAINTAINER | 维护者 |
| ENV | 设定环境变量 |
| ENTRYPOINT | 容器入口 |
| USER | 指定用户 |
| VOLUME | mount point |
注：Dockerfile中的每一行都产生一个新层
Volume：提供独立于容器之外的持久化存储
$ docker run -d --name nginx -v /usr/share/nginx/html nginx
$ docker inspect nginx # 容器所有信息
...
"Mounts": [ # 数据卷
{
"Type": "volume",
"Name": "c6670ae27f24945d3f19267db45e730def339ba36eae1028fa3a94e116eab20e",
"Source": "/var/lib/docker/volumes/c6670ae27f24945d3f19267db45e730def339ba36eae1028fa3a94e116eab20e/_data",
"Destination": "/usr/share/nginx/html",
"Driver": "local",
"Mode": "",
"RW": true,
"Propagation": ""
}
],
...
$ docker exec -it nginx /bin/bash # 进入容器内部
$ cd /usr/share/nginx/html/
第二种数据卷：docker run -v $PWD/code:/var/www/html nginx
$ docker run -p 80:80 -d -v $PWD/html:/usr/share/nginx/html nginx
$ vim index.html # 修改即可生效
第三种Volume：docker run --volumes-from ...
$ docker create -v $PWD/data:/var/mydata --name data_container ubuntu
$ docker run -it --volumes-from data_container ubuntu /bin/bash
Registry（镜像仓库）
术语
| English | 中文 |
|---|---|
| host | 宿主机 |
| image | 镜像 |
| container | 容器 |
| registry | 仓库 |
| daemon | 守护程序 |
| client | 客户端 |
$ docker search whalesay
$ docker pull whalesay
$ docker push myname/whalesay
compose介绍（多容器app）
Linux下安装docker-compose
$ curl -L https://github.com/docker/compose/releases/download/1.9.0/docker-compose-$(uname -s)-$(uname -m) > /usr/local/bin/docker-compose
$ chmod a+x /usr/local/bin/docker-compose
$ docker-compose --version
github中提示安装方式的写法为：
$ curl -L https://github.com/docker/compose/releases/download/1.22.0/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose
$ chmod +x /usr/local/bin/docker-compose
docker-compose实战
docker-compose.yaml
ghost-app:
build: ghost
depends_on:
- db
ports:
- "2368:2368"
nginx:
build: nginx
ports:
- "80:80"
depends_on:
- ghost-app
db:
image: "mysql:5.7.15"
实战部分
目录：$PWD/ghost/下：
$ mkdir ghost
$ mkdir data
$ mkdir nginx
$ cd ghost
$ vim Dockerfile
FROM ghost
COPY ./config.js /var/lib/ghost/config.js
EXPOSE 2368
CMD ["npm","start","--production"]
$ vim config.js
var path = require('path'),
config;
config = {
production: {
url: 'http://mytestblog.com',
mail: {},
database: {
client: 'mysql',
connection: {
host : 'db',
user : 'ghost',
password : 'ghost',
database : 'ghost',
port: '3306',
charset : 'utf8'
},
debug: false
},
paths: {
contentPath: path.join(process.env.GHOST_CONTENT,'/')
},
server: {
host: '0.0.0.0',
port: '2368'
}
}
};
module.exports = config;
cd ./nginx
$ vim Dockerfile
FROM nginx
COPY nginx.conf /etc/nginx/nginx.conf
EXPOSE 80
$ vim nginx.conf
worker processes 4;
events {worker connections 1024;}
http {
server {
listen 80;
location / {
proxy pass http://ghost-app:2368;
}
}
}
cd ./ghost
$ vim docker-compose.yml
version: '2'
networks:
ghost:
services:
ghost-app:
build: ghost
networks:
- ghost
depends_on:
- db
ports:
- "2368:2368"
nginx:
build: nginx
networks:
- ghost
depends_on:
- ghost-app
ports:
- "80:80"
db:
image: "mysql:5.7.15"
networks:
- ghost
environment:
MYSQL_ROOT_PASSWORD: mysqlroot
MYSQL_USER: ghost
MYSQL_PASSWORD: ghost
volumes:
- $PWD/data:/var/libmysql
ports:
- "3306:3306"
进入 $PWD/ghost/ 执行
$ docker-compose up -d # 构建服务
$ docker-compose stop # 停止服务
