在docker下创建自己的image

简介：介绍两种方式创建image：从Dockerfile 生成新的image，使用docker build命令；在原有image上改进生成新的image，直接pull  image，install  and commit； 

方式一：在原有image上通过Dockerfile生成新的image

eg:在ubuntu 14.04 版本上添加ruby 功能

第一步. 编辑Dockerfile

  root@ubuntu-daisy:~#mkdir daisy_dockerbuild

root@ubuntu-daisy:~#ls

bamboo  daisy_dockerbuild  index.html  sinatra

root@ubuntu-daisy:~#cd daisy_dockerbuild/

root@ubuntu-daisy:~/daisy_dockerbuild#touch Dockerfile

root@ubuntu-daisy:~/daisy_dockerbuild# ls
Dockerfile

打开Dockfile 编辑内容：

root@ubuntu-daisy:~/daisy_dockerbuild#vim Dockerfile

root@ubuntu-daisy:~/daisy_dockerbuild#cat Dockerfile
FROM ubuntu:14.04
RUN export http_proxy=http://proxy-prc.webl.com:911 && export https_proxy=https://proxy-prc.web.com:911 && apt-get update && apt-get install -y ruby ruby-dev

开始build  image
root@ubuntu-daisy:~/daisy_dockerbuild#docker build -t ubuntu .
Sending build context to Docker daemon 2.048 kB
Step 1 : FROM ubuntu:14.04
  ---> 4a725d3b3b1c
Step 2 : RUN export http_proxy=http://proxy-prc.intel.com:911 && export https_proxy=https://proxy-prc.intel.com:911 && apt-get update && apt-get install -y ruby ruby-dev
 ---> Using cache
  ---> 6b2695fa32bf
Successfully built 6b2695fa32bf

查看已经建立成功

root@ubuntu-daisy:~/daisy_dockerbuild# docker images
REPOSITORY                  TAG                 IMAGE ID            CREATED                    SIZE
ubuntu                      latest              6b2695fa32bf        About an hour ago           306.8 MB

方式二：在原有image上改进生成新的image

  首先查找你需要的image

root@ubuntu-daisy:~# docker search sinatra
NAME                                         DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
hwada/sinatra                               sinatra for hands on of aws-docker-fluentd-s3   0                    [OK]
kerona/sinatra                                                                               0                    [OK]

root@ubuntu-daisy:~# docker pull kerona/sinatra

以kerona/sinatra 容器为基础，再建一个container
root@ubuntu-daisy:~# docker run -t -i kerona/sinatra /bin/bash

root@7199eb77c75c:/# export http_proxy=http://proxy-prc.web.com:911        // 设置代理
root@7199eb77c75c:/# export https_proxy=https://proxy-prc.web.com:911

root@7199eb77c75c:/# apt-get install -y ruby2.0-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  ruby2.0-dev
0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
Need to get 908 kB of archives.
After this operation, 4323 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu/ trusty-updates/main ruby2.0-dev amd64 2.0.0.484-1ubuntu2.2 [908 kB]
Fetched 908 kB in 2s (306 kB/s)
Selecting previously unselected package ruby2.0-dev:amd64.
(Reading database ... 16609 files and directories currently installed.)
Preparing to unpack .../ruby2.0-dev_2.0.0.484-1ubuntu2.2_amd64.deb ...
Unpacking ruby2.0-dev:amd64 (2.0.0.484-1ubuntu2.2) ...
Setting up ruby2.0-dev:amd64 (2.0.0.484-1ubuntu2.2) ...

root@ubuntu-daisy:~# docker commit -m "Added ruby" -a "daisy" 62b83f189561 daisy/sinatra:v2
sha256:203b756a3edfd0f617a8e41dfefe3f411c41b4e3388b07cf012fdbe4a8b3ebb2

查看已经生成了自己的image
root@ubuntu-daisy:~# docker images
REPOSITORY                  TAG                 IMAGE ID            CREATED             SIZE
daisy/sinatra               v2                  203b756a3edf        16 seconds ago      316.4 MB

两种方法，其中方法一更方便使用，也便于team内共享。在创建own image 时，我需要每次都设置http是因为公司网络是代理的缘故，正常情况不用设置就能连上网。