1.启动一个Docker容器
[root@localhost ~]# docker run -i -t Ubuntu /bin/bash
Unable to find image 'ubuntu' locally
Pulling repository ubuntu
04c5d3b7b065: Download complete
511136ea3c5a: Download complete
c7b7c6419568: Download complete
70c8faa62a44: Download complete
d735006ad9c1: Download complete
Status: Downloaded newer image for ubuntu:latest
注：
-i:打开容器中的STDIN
-t:为容器分配一个伪tty终端
从上面我们可以看出，首先Docker会检查本地是否存在ubuntu镜像，如果在本地没有找到该镜像的话，那么Docker就会去官方的Docker Hub Registry查看Docker Hub中是否有该镜像。Docker一旦找到该镜像，就会下载该镜像并将其保存到本地的宿主机中。
然后，Docker在文件系统内部用这个镜像创建了一个新的容器。该容器拥有自己的网络、IP地址，以及一个用来可以和宿主机进行通信的桥接网络接口。最后，我们告诉Docker在新容器中要运行什么命令。
当容器创建完毕之后，Docker就会执行容器中的/bin/bash命令。这时间我们就可以看到容器内的shell
root@8c342c0c275c:/#
注：8c342c0c275c代表容器的ID
2.使用容器
查看该容器的主机名
root@8c342c0c275c:/# hostname
8c342c0c275c
可以看到，容器的主机名就是该容器的ID
查看该主机的hosts文件
root@8c342c0c275c:/# cat /etc/hosts
172.17.0.2 8c342c0c275c
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
可以看到Docker为该容器的IP地址添加了一条主机配置项。
查看该容器的IP地址
root@8c342c0c275c:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
4: eth0: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.2/16 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::42:acff:fe11:2/64 scope link
valid_lft forever preferred_lft forever
查看容器中运行的进程
root@8c342c0c275c:/# ps -aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.1 18168 1976 ? Ss 09:38 0:00 /bin/bash
root 19 0.0 0.0 15568 1144 ? R+ 09:55 0:00 ps -aux
在容器中安装一个软件包
root@8c342c0c275c:/# apt-get update && apt-get install vim
Ign trusty InRelease
Ign trusty-updates InRelease
Ign trusty-security InRelease
Hit trusty Release.gpg
Get:1 trusty-updates Release.gpg [933 B]
Get:2 trusty-security Release.gpg [933 B]
Hit trusty Release
Get:3 trusty-updates Release [62.0 kB]
Get:4 trusty-security Release [62.0 kB]
Get:5 trusty/main Sources [1335 kB]
Get:6 trusty/restricted Sources [5335 B]
Get:7 trusty/universe Sources [7926 kB]
Get:8 trusty/main amd64 Packages [1743 kB]
Get:9 trusty/restricted amd64 Packages [16.0 kB]
Get:10 trusty/universe amd64 Packages [7589 kB]
Get:11 trusty-updates/main Sources [193 kB]
Get:12 trusty-updates/restricted Sources [1874 B]
Get:13 trusty-updates/universe Sources [119 kB]
Get:14 trusty-updates/main amd64 Packages [493 kB]
Get:15 trusty-updates/restricted amd64 Packages [14.8 kB]
Get:16 trusty-updates/universe amd64 Packages [298 kB]
Get:17 trusty-security/main Sources [70.1 kB]
Get:18 trusty-security/restricted Sources [1874 B]
Get:19 trusty-security/universe Sources [19.1 kB]
Get:20 trusty-security/main amd64 Packages [229 kB]
Get:21 trusty-security/restricted amd64 Packages [14.8 kB]
Get:22 trusty-security/universe amd64 Packages [98.1 kB]
Fetched 20.3 MB in 41s (490 kB/s)
Reading package lists... Done
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
libgpm2 libPython2.7 libpython2.7-minimal libpython2.7-stdlib vim-runtime
Suggested packages:
gpm ctags vim-doc vim-scripts
The following NEW packages will be installed:
libgpm2 libpython2.7 libpython2.7-minimal libpython2.7-stdlib vim
vim-runtime
0 upgraded, 6 newly installed, 0 to remove and 2 not upgraded.
Need to get 9083 kB of archives.
After this operation, 42.9 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 trusty/main libgpm2 amd64 1.20.4-6.1 [16.5 kB]
Get:2 trusty/main libpython2.7-minimal amd64 2.7.6-8 [307 kB]
Get:3 trusty/main libpython2.7-stdlib amd64 2.7.6-8 [1872 kB]
Get:4 trusty/main libpython2.7 amd64 2.7.6-8 [1044 kB]
Get:5 trusty/main vim-runtime all 2:7.4.052-1ubuntu3 [4888 kB]
Get:6 trusty/main vim amd64 2:7.4.052-1ubuntu3 [956 kB]
Fetched 9083 kB in 51s (175 kB/s)
Selecting previously unselected package libgpm2:amd64.
(Reading database ... 11527 files and directories currently installed.)
Preparing to unpack .../libgpm2_1.20.4-6.1_amd64.deb ...
Unpacking libgpm2:amd64 (1.20.4-6.1) ...
Selecting previously unselected package libpython2.7-minimal:amd64.
Preparing to unpack .../libpython2.7-minimal_2.7.6-8_amd64.deb ...
Unpacking libpython2.7-minimal:amd64 (2.7.6-8) ...
Selecting previously unselected package libpython2.7-stdlib:amd64.
Preparing to unpack .../libpython2.7-stdlib_2.7.6-8_amd64.deb ...
Unpacking libpython2.7-stdlib:amd64 (2.7.6-8) ...
Selecting previously unselected package libpython2.7:amd64.
Preparing to unpack .../libpython2.7_2.7.6-8_amd64.deb ...
Unpacking libpython2.7:amd64 (2.7.6-8) ...
Selecting previously unselected package vim-runtime.
Preparing to unpack .../vim-runtime_2%3a7.4.052-1ubuntu3_all.deb ...
Adding 'diversion of /usr/share/vim/vim74/doc/help.txt to /usr/share/vim/vim74/doc/help.txt.vim-tiny by vim-runtime'
Adding 'diversion of /usr/share/vim/vim74/doc/tags to /usr/share/vim/vim74/doc/tags.vim-tiny by vim-runtime'
Unpacking vim-runtime (2:7.4.052-1ubuntu3) ...
Selecting previously unselected package vim.
Preparing to unpack .../vim_2%3a7.4.052-1ubuntu3_amd64.deb ...
Unpacking vim (2:7.4.052-1ubuntu3) ...
Setting up libgpm2:amd64 (1.20.4-6.1) ...
Setting up libpython2.7-minimal:amd64 (2.7.6-8) ...
Setting up libpython2.7-stdlib:amd64 (2.7.6-8) ...
Setting up libpython2.7:amd64 (2.7.6-8) ...
Setting up vim-runtime (2:7.4.052-1ubuntu3) ...
Processing /usr/share/vim/addons/doc
Setting up vim (2:7.4.052-1ubuntu3) ...
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vim (vim) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vimdiff (vimdiff) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/rvim (rvim) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/rview (rview) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vi (vi) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/view (view) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/ex (ex) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/editor (editor) in auto mode
Processing triggers for libc-bin (2.19-0ubuntu6.4) ...
退出容器
root@8c342c0c275c:/# exit
exit