Docker初次接触

最近看了不少docker介绍性文章,也听了不少公开课,于是今天去官网逛了逛,发现了一个交互式的小教程于是决定跟着学习下。只是把觉得重点的知识记录下来,不是很系统的学习和笔记。

理论部分

  • Docker 引擎包含了两个部分,一个守护进程作为服务器端来管理所有的容器。一个客户端,可以远程来控制服务端。
  • Docker有公共的云端仓库 Docker Hub Registry,里面有可以使用的镜像
  • 你可以认为容器containers就是沙箱box中的一个进程。这个盒子中包括了所有一个进程需要的东西,文件系统,系统库,shell等等,只是默认情况下他们是没有运行的。
  • 我们可以在操纵和改变容器,然后通过命令保存成新的镜像
  • 在需要使用容器id的地方,我们可以只输入前几个字符

操作部分

docker help 可以查看能使用的命令和简单描述

查看版本

you@tutorial:~$ docker version
Docker Emulator version 0.1.3
Emulating:
Client version: 0.5.3
Server version: 0.5.3
Go version: go1.1

从公共云仓库中查找一个镜像 tutorial

you@tutorial:~$ docker search tutorial
Found 1 results matching your query ("tutorial")
NAME                      DESCRIPTION
learn/tutorial            An image for the interactive tutorial

从仓库中拉取一个镜像,注意要写这个镜像的全名

you@tutorial:~$ docker pull learn/tutorial
Pulling repository learn/tutorial from https://index.docker.io/v1
Pulling image 8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c (precise) from ubuntu
Pulling image b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc (12.10) from ubuntu
Pulling image 27cf784147099545 () from tutorial

启动一个docker并且运行命令

you@tutorial:~$ docker run learn/tutorial echo "hello boy"
hello boy

tips:这里是启动了一个容器并且运行了一个命令,当命令运行完的时候容器就停止了。可以通过docker的ps命令查看当前正在运行的容器。

you@tutorial:~$ docker ps
ID                  IMAGE               COMMAND               CREATED             STATUS              PORTS

安装一个软件ping

you@tutorial:~$ docker run learn/tutorial apt-get install -y ping
Reading package lists...
Building dependency tree...
The following NEW packages will be installed:
  iputils-ping
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 56.1 kB of archives.
After this operation, 143 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu/ precise/main iputils-ping amd64 3:20101006-1ubuntu1 [56.1 kB]
debconf: delaying package configuration, since apt-utils is not installed
Fetched 56.1 kB in 1s (50.3 kB/s)
Selecting previously unselected package iputils-ping.
(Reading database ... 7545 files and directories currently installed.)
Unpacking iputils-ping (from .../iputils-ping_3%3a20101006-1ubuntu1_amd64.deb) ...
Setting up iputils-ping (3:20101006-1ubuntu1)

查看改变之后的容器,然后保存成learn/ping

you@tutorial:~$ docker ps -l
ID                  IMAGE               COMMAND                CREATED             STATUS              PORTS
6982a9948422        ubuntu:12.04        apt-get install ping   1 minute ago        Exit 0
you@tutorial:~$ docker commit 6982 learn/ping
effb66b31edb

使用新的镜像ping google

you@tutorial:~$ docker run learn/ping ping www.google.com
PING www.google.com (74.125.239.129) 56(84) bytes of data.
64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=1 ttl=55 time=2.23 ms
64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=2 ttl=55 time=2.30 ms
64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=3 ttl=55 time=2.27 ms
64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=4 ttl=55 time=2.30 ms

查看正在运行的容器的状态

you@tutorial:~$ docker ps
ID                  IMAGE               COMMAND               CREATED             STATUS              PORTS
efefdc74a1d5        learn/ping:latest   ping www.google.com   37 seconds ago      Up 36 seconds
you@tutorial:~$ docker inspect efef
[2013/07/30 01:52:26 GET /v1.3/containers/efef/json
{
  "ID": "efefdc74a1d5900d7d7a74740e5261c09f5f42b6dae58ded6a1fde1cde7f4ac5",
  "Created": "2013-07-30T00:54:12.417119736Z",
  "Path": "ping",
  "Args": [
      "www.google.com"
  ],
  "Config": {
      "Hostname": "efefdc74a1d5",
      "User": "",
      "Memory": 0,
      "MemorySwap": 0,
      "CpuShares": 0,
      "AttachStdin": false,
      "AttachStdout": true,
      "AttachStderr": true,
      "PortSpecs": null,
      "Tty": false,
      "OpenStdin": false,
      "StdinOnce": false,
      "Env": null,
      "Cmd": [
          "ping",
          "www.google.com"
      ],
      "Dns": null,
      "Image": "learn/ping",
      "Volumes": null,
      "VolumesFrom": "",
      "Entrypoint": null
  },
  "State": {
      "Running": true,
      "Pid": 22249,
      "ExitCode": 0,
      "StartedAt": "2013-07-30T00:54:12.424817715Z",
      "Ghost": false
  },
  "Image": "a1dbb48ce764c6651f5af98b46ed052a5f751233d731b645a6c57f91a4cb7158",
  "NetworkSettings": {
      "IPAddress": "172.16.42.6",
      "IPPrefixLen": 24,
      "Gateway": "172.16.42.1",
      "Bridge": "docker0",
      "PortMapping": {
          "Tcp": {},
          "Udp": {}
      }
  },
  "SysInitPath": "/usr/bin/docker",
  "ResolvConfPath": "/etc/resolv.conf",
  "Volumes": {},
  "VolumesRW": {}

查看本地镜像

you@tutorial:~$ docker images
ubuntu                latest              8dbd9e392a96        4 months ago        131.5 MB (virtual 131.5 MB)
learn/tutorial        latest              8dbd9e392a96        2 months ago        131.5 MB (virtual 131.5 MB)
learn/ping            latest              effb66b31edb        10 minutes ago      11.57 MB (virtual 143.1 MB)

把镜像推送到云端

docker inspect efe

tips: 这个是推送到docker的云仓库的,会有你自己的独立命名控件,账号注册地址

这个十分钟交互式的短教程可以让我们对docker有个感性的认识,最基本的使用和激发兴趣。