Docker容器简用

一、安装
①RedHat/CentOS下的docker安装
RedHat/CentOS必须要6.6版本以上，或者7.x才能安装docker，建议在RedHat/CentOS 7上使用docker，因为RedHat/CentOS 7的内核升级到了kernel 3.10，对lxc容器支持更好。

# yum -y install docker
# systemctl start docker

②Ubuntu下docker安装

# sudo apt-get install docker.io
# service docker.io start

二、查看docker版本

# docker version
Client:
Version:      1.8.2-el7.centos
API version:  1.20
Package Version: docker-1.8.2-10.el7.centos.x86_64
Go version:   go1.4.2
Git commit:   a01dc02/1.8.2
Built:
OS/Arch:      linux/amd64
Server:
Version:      1.8.2-el7.centos
API version:  1.20
Package Version:
Go version:   go1.4.2
Git commit:   a01dc02/1.8.2
Built:
OS/Arch:      linux/amd64

三、查看docker安装的相关信息

# docker info
Containers: 1
Images: 6
Storage Driver: devicemapper
Pool Name: docker-253:0-35256846-pool
Pool Blocksize: 65.54 kB
Backing Filesystem: xfs
Data file: /dev/loop0
Metadata file: /dev/loop1
Data Space Used: 2.052 GB
Data Space Total: 107.4 GB
Data Space Available: 14.88 GB
Metadata Space Used: 1.774 MB
Metadata Space Total: 2.147 GB
Metadata Space Available: 2.146 GB
Udev Sync Supported: true
Deferred Removal Enabled: false
Data loop file: /var/lib/docker/devicemapper/devicemapper/data
Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
Library Version: 1.02.107-RHEL7 (2015-10-14)
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 3.10.0-229.el7.x86_64
Operating System: CentOS Linux 7 (Core)
CPUs: 1
Total Memory: 475.7 MiB
Name: docker
ID: 22N4:5F3A:UW62:O5MQ:LVV2:RLQY:3YFU:AABC:DJFC:3HNV:UG3E:7OEK

四、列出、搜索镜像

# docker images                           ##列出本地已有的镜像
# docker  search cenots                   ##从默认镜像仓库搜索镜像

注:没有/分隔前缀的表示官方镜像,尽量选择官方镜像或者下载量较高的镜像使用

五、下载镜像并查看
①下载Ubuntu15.10

# docker  pull ubuntu:15.10
3e0c71ada2db: Download complete
6cd64557b0fd: Download complete
b53bfb363b42: Download complete
7644a86243c4: Download complete
Status: Downloaded newer image for docker.io/ubuntu:15.10

②下载CentOS7

# docker  pull centos:7
60e65a8e4030: Download complete
47d44cb6f252: Download complete
838c1c5c4f83: Download complete
5764f0a31317: Download complete
Status: Downloaded newer image for docker.io/centos:7

③查看镜像

# docker images
REPOSITORY           TAG       IMAGE ID      CREATED      VIRTUAL SIZE
储存库             标签       镜像ID       创建时间         大小
docker.io/centos    7        60e65a8e4030  2 weeks ago         196.6 MB
docker.io/ubuntu    15.10    3e0c71ada2db  4 weeks ago         133.5 MB

六、启动一个docker容器
# docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
主要选项：

-d : 以后台进行方式运行容器
-t : 提供一个伪终端
-i : 提供交互输入,一般与“-t”一起使用,如只提供“-i”选项，则容器启动后无法退出
-v : 映射一个volume给容器，如： -p /data/www:/var/www/html
-p : 将容器的端口映射给宿主机，如： -p 8080:80

实例1:

# docker run -it centos:7 /bin/bash       ##以交互方式启动一个容器
[root@12984bf5e533 /]# ls
anaconda-post.log  dev  home  lib64       media  opt   root  sbin  sys  usr
bin                etc  lib   lost+found  mnt    proc  run   srv   tmp  var
[root@12984bf5e533 /]# exit
exit

# docker commit -m "centos" -a "zhi" 12984bf5e533 zhi/centos:v1
016e8163a8b0dcc93c7ea651bb8e6f9490a1f4321e2c2df0be6d1b6b08c12ad3

注:commit命令用来将容器转化为镜像，-m参数用来指定提交的说明信息；
-a参数用来指定用户信息；12984bf5e533指容器的ID；
zhi/centos:v1指定目标镜像的用户名、仓库名及tag信息。创建成功后会返回该镜像的ID信息。

# docker images                     ##列出镜像列表
REPOSITORY     TAG      IMAGE ID      CREATED              VIRTUAL SIZE
zhi/centos     v1     016e8163a8b  About a minute ago       196.6 MB
docker.io/centos  7   60e65a8e4030        4 weeks ago          196.6 MB
docker.io/ubuntu 15.10  3e0c71ada2db        7 weeks ago          133.5 MB
# docker run -it zhi/centos:v1
[root@05c5000250ea /]# uname
Linux

实例2:

# docker run -it ubuntu:15.10
root@c340d2ffb0a0:/# apt-get update
root@c340d2ffb0a0:/# sudo apt-get -y install nginx
root@c340d2ffb0a0:/# nginx -v
nginx version: nginx/1.9.3 (Ubuntu)
root@c340d2ffb0a0:/# exit
exit

# docker ps                             ##查看当前运行的容器
# docker ps -a                   ##查看所有容器，包括已停止容器
# docker commit -m "Nginx in Ubuntu" -a "zhi" c340d2ffb0a0 zhi/ubuntu-nginx:v1
ceb3f407b6c4959514d72a420e4c0d3ade47d6b401eb6d2b5cbfd51f58918918
# docker images
REPOSITORY         TAG     IMAGE ID   CREATED VIRTUAL   SIZE
zhi/ubuntu-nginx    v1   ceb3f407b6c4 53 seconds ago   237.7 MB

# docker run -it zhi/ubuntu-nginx:v1
root@9cf8bba7784b:/# nginx -v
nginx version: nginx/1.9.3 (Ubuntu)

六、推送镜像到 Docker Hub

# docker login              ##创建docker hub帐号(也可网页注册)
Username: wangzhijian
Password:
Email: wangzhijiansd@qq.com
WARNING: login credentials saved in /root/.docker/config.json
Account created. Please use the confirmation link we sent to your e-mail to activate it.
# docker login                    ##进行登录
Username (wangzhijian): wangzhijian
WARNING: login credentials saved in /root/.docker/config.json
Login Succeeded
# docker push zhi/ubuntu-nginx     ##推送镜像到 Docker Hub
# docker rmi user/ubuntu:docker          ##移除镜像
Untagged: user/ubuntu:docker
Deleted: 6373a9f4d5704ea80ad7d1d93e98f1094341b038ef266ef0ba332c5878f28ded
Deleted: cfeb58b1dc4e657387dc0495f651e0771b6079870f259548f86f01d77652a187

七、使用 Dockerfile 构建镜像
①编写dockerfile文件

# mkdir docker
# cd docker/
# touch dockerfile
# vi dockerfile
# This is a comment
FROM ubuntu
MAINTAINER zhi&j <wangzhijiansd@qq.com>
RUN apt-get update && apt-get install -y nginx

注:
第一行为注释同时每一个指令的前缀都必须是大写的；
第二行FROM告诉Docker所使用的镜像源；
第三行使用 MAINTAINER 指令来指定谁在维护这个新镜像；
第四行指定了两个 RUN 指令，RUN 指令在镜像内执行一条命令，这里更新
APT缓存并安装nginx

②通过 docker build 命令来构建一个镜像

# docker build -t wangzhijian/ubuntu:one .
Sending build context to Docker daemon 2.048 kB
Step 0 : FROM ubuntu
---> d55e68e6cc9c
Step 1 : MAINTAINER zhi&j <wangzhijiansd@qq.com>
---> Running in a8e92a582884
---> cfeb58b1dc4e
Removing intermediate container a8e92a582884
Step 2 : RUN apt-get update && apt-get install -y nginx
---> Running in aeba1f533058

解释:
-t标示属于wangzhijian,镜像名称为ubuntu，标签是one，"."指定dockerfile所在

八、设置镜像标签

# docker images
REPOSITORY  TAG     IMAGE ID         CREATED         VIRTUAL SIZE
<none>     <none> 6373a9f4d570   About an hour ago     227.6 MB
# docker tag 6373a9f4d570 user/ubuntu:docker
# docker images
REPOSITORY     TAG     IMAGE ID       CREATED        VIRTUAL SIZE
user/ubuntu   docker 6373a9f4d570  About an hour ago   227.6 MB

Image Digests
内容定位标示符叫做 digest。只要用于生成镜像的镜像源不更改，digests 值就是可以预料的。使用 --digests 标识来列出镜像 digests 的值

# docker images --digests | head
REPOSITORY         TAG   DIGEST    IMAGE ID      CREATED     VIRTUAL SIZE
docker.io/centos latest  <none>  14dab3d40372  2 weeks ago     194.7 MB
docker.io/ubuntu latest  <none>  d55e68e6cc9c  3 weeks ago     187.9 MB

九、在Docker中运行Reids服务

# mkdir docker
# cd docker/
# touch dockerfile
# vi dockerfile
FROM        ubuntu
RUN         apt-get update
RUN         apt-get -y install redis-server
EXPOSE      6379
ENTRYPOINT  ["/usr/bin/redis-server"]
# docker build -t redis/ubuntu .

本文出自 “记事本” 博客，请务必保留此出处http://wangzhijian.blog.51cto.com/6427016/1750858