Docker安装与镜像管理
一、安装dockeryum install epel-resase
yum install docker-io（RHEL6）
yum install docker （RHEL7）
系统：
# uname -a
Linux kvm.huangming.org 2.6.32-573.el6.x86_64 #1 SMP Thu Jul 23 15:44:03 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
# cat /etc/issue
CentOS release 6.7 (Final)
Kernel \r on an \m
二、启动docker
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# /etc/init.d/docker start
Starting docker:
# ps -ef |grep docker
root 3900 11 19:28 pts/0 00:00:00 /usr/bin/docker -d
root 3927 3900 34 19:28 pts/0 00:00:04 mkfs.ext4 -E nodiscard,lazy_itable_init=0 /dev/mapper/docker-8:3-1573967-base
root 3938 36060 19:28 pts/0 00:00:00 grep docker
三、镜像管理
[*]docker pull centos
#从docker.com获取centos镜像
[*]docker images
#查看本地镜像
[*]docker tag centos test-img
#为centos镜像设置标签为test-img，在使用docker image查看时会多出一行，更改的image id和centos的一样
[*]docker search
#搜索docker仓库里的docker镜像
[*]docker run -t -i centos /bin/bash
#用下载到的镜像开启容器，-i表示让容器的标准输入打开，-t表示分配一个伪终端，要把-i -t放到镜像名字的前面。当镜像发生修改后，我们可以把该镜像提交重新生成一个新版本运行在本地
[*]docker ps
#查看运行的容器，加-a选项可以查看没有运行的容器
[*]docker rmi centos
#用来删除指定的镜像，其中后面的参数可以是tag，如果是tag时，实际上是删除该tag，只要该镜像还有其他的tag，就不会删除该镜像。当后面的参数为ID时，则会彻底删除整个镜像，连同所有的标签。
1、下载centos镜像
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# docker pull centos
latest: Pulling from centos
47d44cb6f252: Already exists
6fdebd7b0eb5: Already exists
a63aae4d216f: Already exists
Digest: sha256:381f21e4c7b3724c6f420b2bcfa6e13e47ed155192869a2a04fa10f944c78476
Status: Image is up to date for centos:latest
2、查看下载到本地镜像
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# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
centos latest bb3d629a7cbc 3 weeks ago 196.6 MB
3、查看docker仓库镜像
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# docker search centos
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
centos The official build of CentOS. 2069
jdeathe/centos-ssh CentOS-6 6.7 x86_64 / CentOS-7 7.2.1511 x8... 18
jdeathe/centos-ssh-apache-php CentOS-6 6.7 x86_64 / Apache / PHP / PHP M... 14
million12/centos-supervisor Base CentOS-7 with supervisord launcher, h... 10
blalor/centos Bare-bones base CentOS 6.5 image 8
nimmis/java-centos This is docker images of CentOS 7 with dif... 8
torusware/speedus-centos Always updated official CentOS docker imag... 7
centos/mariadb55-centos7 3
nathonfowlie/centos-jre Latest CentOS image with the JRE pre-insta... 3
nickistre/centos-lamp LAMP on centos setup 3
consol/sakuli-centos-xfce Sakuli end-2-end testing and monitoring co... 2
softvisio/centos Centos 1
layerworx/centos CentOS container with etcd, etcdctl, confd... 1
yajo/centos-epel CentOS with EPEL and fully updated 1
lighthopper/orientdb-centos A Dockerfile for creating an OrientDB imag... 1
darksheer/centos Base Centos Image -- Updated hourly 1
timhughes/centos Centos with systemd installed and running 1
januswel/centos yum update-ed CentOS image 0
drokar/centos-s6 centOS combined with s6, a small process s... 0
lighthopper/openjdk-centos A Dockerfile for creating an OpenJDK image... 0
ustclug/centos USTC centos 0
blacklabelops/centos CentOS Base Image! Built and Updates Daily! 0
grayzone/centos auto build for centos. 0
jsmigel/centos-epel Docker base image of CentOS w/ EPEL installed 0
grossws/centos CentOS 6 and 7 base images with gosu and l... 0
4、开启一个容器docker run -it centos /bin/bash
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# docker run -it centos /bin/bash
#
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# cat /etc/redhat-release
CentOS Linux release 7.2.1511 (Core)
# uname -a
Linux 8c1fd812d079 2.6.32-573.el6.x86_64 #1 SMP Thu Jul 23 15:44:03 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
# w
11:55:12 up 42 min,0 users,load average: 0.00, 0.03, 0.01
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
# ps
PID TTY TIME CMD
1 ? 00:00:00 bash
16 ? 00:00:00 ps
# uptime
11:55:21 up 42 min,0 users,load average: 0.00, 0.02, 0.01
# df -Th
Filesystem Type SizeUsed Avail Use% Mounted on
/dev/mapper/docker-8:3-1573967-8c1fd812d0790d1868bcec389a50c6f7a08c6c099167141393af0961e7b850be ext4 9.8G230M9.0G 3% /
tmpfs tmpfs1.9G 01.9G 0% /dev
shm tmpfs 64M 0 64M 0% /dev/shm
/dev/sda3 ext4 43G4.6G 36G12% /etc/hosts
# exit
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# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f732106147eb centos "/bin/bash" 17 seconds ago Up 15 seconds high_heisenberg
8c1fd812d079 centos "/bin/bash" 3 minutes ago Exited (0) About a minute ago grave_mcclintock
5、修改镜像名称
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# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
centos latest bb3d629a7cbc 3 weeks ago 196.6 MB
# docker tag centos test-img
# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
centos latest bb3d629a7cbc 3 weeks ago 196.6 MB
test-img latest bb3d629a7cbc 3 weeks ago 196.6 MB
# docker tag test-img centos:test-img2
# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
test-img latest bb3d629a7cbc 3 weeks ago 196.6 MB
centos latest bb3d629a7cbc 3 weeks ago 196.6 MB
centos test-img2 bb3d629a7cbc 3 weeks ago 196.6 MB
6、删除镜像
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# docker rmi centos:test-img2
Untagged: centos:test-img2
# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
centos latest bb3d629a7cbc 3 weeks ago 196.6 MB
test-img latest bb3d629a7cbc 3 weeks ago 196.6 MB
四、docker镜像使用容器生成新的镜像
1、启动镜像
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# docker start 8c1fd
8c1fd
# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f732106147eb centos "/bin/bash" 12 minutes ago Exited (0) 43 seconds ago high_heisenberg
8c1fd812d079 centos "/bin/bash" 15 minutes ago Up 3 seconds
2、进入已启动的容器docker exec -it 【镜像ID，可以简写】 /bin/bash
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# docker exec -it 8c1fd /bin/bash
#
3、在容器中安装软件（安装网卡包net-tools）
# yum install net-tools wget -y
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# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>mtu 1500
inet 172.17.0.3netmask 255.255.0.0broadcast 0.0.0.0
inet6 fe80::42:acff:fe11:3prefixlen 64scopeid 0x20<link>
ether 02:42:ac:11:00:03txqueuelen 0(Ethernet)
RX packets 5419bytes 10411538 (9.9 MiB)
RX errors 0dropped 0overruns 0frame 0
TX packets 4127bytes 268377 (262.0 KiB)
TX errors 0dropped 0 overruns 0carrier 0collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING>mtu 65536
inet 127.0.0.1netmask 255.0.0.0
inet6 ::1prefixlen 128scopeid 0x10<host>
looptxqueuelen 0(Local Loopback)
RX packets 0bytes 0 (0.0 B)
RX errors 0dropped 0overruns 0frame 0
TX packets 0bytes 0 (0.0 B)
TX errors 0dropped 0 overruns 0carrier 0collisions 0
4、生成新的镜像
[*]docker commit -m "change somth" -a "somebody info" container_id new-image
例如：docker commit -m "install httpd" -a "test-image1" 8c1fd812d079 test/centos
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# docker commit -m "centos_with_nettools_and_wget" -a "author" 8c1fd812d079 centos_new1
3e4be15719e03e909f39a7c03f3c7cd4fa6f2a8e282b2b88204d0224104b20e6
# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
centos_new1 latest 3e4be15719e0 16 seconds ago 268 MB
centos latest bb3d629a7cbc 3 weeks ago 196.6 MB
test-img latest bb3d629a7cbc 3 weeks ago 196.6 MB
五、docker基于本地模版导入创建镜像
1、下载地址https://download.openvz.org/template/precreated/
2、下载一个镜像模版
[*]导入镜像
#cat centos-6-x86_64-minimal.tar.gz | docker import - centos-6-x86_64
[*]导出镜像
#docker save -o new-centos.tar new-image/centos
[*]恢复本地镜像
#docker load --input new-centos.tar 或者 docker load < new-centos.tar
[*]上传镜像到dockerhub官网，前提需要注册一个用户
#docker push image-name
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