Docker - 管理镜像
文章目录
本文将会说明通过Docker命令行如何显示本机当前的镜像, 如何拉取镜像, 如何搜索Docker hub上的镜像, 以及如何创建自定义镜像并提交到Docker hub
列出本地已下载镜像
线性列表
1 | root@localhost:~# docker images REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE ubuntu 14.04 c4ff7513909d 2 weeks ago 213 MB ubuntu latest c4ff7513909d 2 weeks ago 213 MB training/webapp latest 31fa814ba25a 3 months ago 278.6 MB |
树状列表
1 | root@localhost:~# docker images --tree Warning: '--tree' is deprecated, it will be removed soon. See usage. ├─8d9098e943e3 Virtual Size: 797.3 MB Tags: developerworks/buildserver:latest ├─fb98151c15f0 Virtual Size: 595.4 MB Tags: developerworks/base:latest ├─d4efe79a7adf Virtual Size: 595.4 MB │ └─dab0f78de735 Virtual Size: 596.7 MB Tags: developerworks/base:v1 └─511136ea3c5a Virtual Size: 0 B └─1c9383292a8f Virtual Size: 192.5 MB └─9942dd43ff21 Virtual Size: 192.7 MB └─d92c3c92fa73 Virtual Size: 192.7 MB └─0ea0d582fd90 Virtual Size: 192.7 MB └─cc58e55aa5a5 Virtual Size: 225.4 MB └─c4ff7513909d Virtual Size: 225.4 MB Tags: ubuntu:14.04 |
下载一个新的镜像
1 | root@localhost:~# docker pull centos Pulling repository centos b157b77b1a65: Download complete b1bd49907d55: Download complete 511136ea3c5a: Download complete 34e94e67e63a: Download complete |
搜索镜像
1 | root@localhost:~# docker search gerrit NAME DESCRIPTION STARS OFFICIAL AUTOMATED edgester/gerrit The Gerrit code review system. v2.7 using ... 3 nikolas/gerrit A Docker container for Gerrit code review.... 2 tylerwhall/gerrit-psql 0 [OK] eclipsesource/es-gerrit Internally used Gerrit container 0 jyonkov/gerrit 0 bartk/gerrit 0 erwyn/jenkins-gerrit 0 larrycai/gerrit The Gerrit code review system. v2.8 using ... 0 [OK] jgeewax/gerrit Gerrit + Apache 2. See https://github.com/... 0 |
创建自己的镜像
- 更新从一个镜像创建的容器, 并把更新提交回镜像
- 可以使用
Dockerfile创建一个镜像
更新和提交镜像
我以官方的ubuntu镜像为基础,创建自己的一个镜像, 其中通过apt-get安装了git版本管理工具
- 启动一个容器,并安装
git工具
1 | root@localhost:~# docker run -i -t ubuntu /bin/bash root@89eb687c9446:/# root@89eb687c9446:/# apt-get install -y git |
- 保存一个容器为镜像
记录下需要保存的容器ID 89eb687c9446, 并退出容器
1 | root@89eb687c9446:/# exit |
执行
1 | root@localhost:~# docker commit -m="Install git" -a="developerworks" 89eb687c9446 developerworks/ubuntu:dev 1c34d940014238623d5b4bcc92684db4af8cf0d59d67e28597ec858984ce8ce4 |
终端输出一个64位长度的字符串, 表示成功提交, 我们执行docker images显示一下当前本机的镜像列表
1 | root@localhost:~# docker images REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE developerworks/ubuntu dev 1c34d9400142 12 seconds ago 321.9 MB ubuntu 14.04 c4ff7513909d 2 weeks ago 213 MB ubuntu latest c4ff7513909d 2 weeks ago 213 MB centos centos6 b1bd49907d55 4 weeks ago 212.5 MB centos centos7 b157b77b1a65 4 weeks ago 243.7 MB centos latest b157b77b1a65 4 weeks ago 243.7 MB training/webapp latest 31fa814ba25a 3 months ago 278.6 MB |
在上面的docker images命令输出中, 我们看到刚才创建的developerworks/ubuntu仓库, 其镜像ID为1c34d9400142, 到此, 通过修改容器创建一个镜像的过程就是这样, 接下来说明如何通过Dockerfile创建一个全新的镜像
输入docker commit可查看命令行帮助:
1 | Usage: docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]] Create a new image from a container's changes -a, --author="" Author (e.g., "John Hannibal Smith <hannibal@a-team.com>") -m, --message="" Commit message -p, --pause=true Pause container during commit |
从Dockerfile构建镜像
docker commit命令是一个非常简单的扩展一个镜像的命令. 但是它有些笨重, 并且在团队中分享镜像的开发过程不是一件容易的事情. 为此, 我们用docker build来从头构造一个全新的镜像.
首先, 需要创建一个Dockerfile来告知如何构造一个镜像. 下面的命令是编译Node.js源码并安装
1 | # 创建工作目录 $ mkdir image && cd image # 创建Dockerfile $ echo "FROM ubuntu:14.04 RUN echo 'debconf debconf/frontend select Noninteractive' | debconf-set-selections MAINTAINER developerworks RUN apt-get update RUN apt-get install -y build-essential RUN apt-get install -y wget RUN apt-get install -y python RUN wget http://nodejs.org/dist/v0.10.31/node-v0.10.31.tar.gz RUN tar zxf node-v0.10.31.tar.gz && cd node-v0.10.31 && ./configure && make && make install" > Dockerfile # 构建镜像 $ docker build -t="developerworks/ubuntu-nodejs-runtime" . # 或者 $ docker build -t="developerworks/ubuntu-nodejs-runtime" http://developerworks.github.io/code/docker/Dockerfile |
建议一个RUN只运行单条命令, 成功创建镜像后,RUN命令的结果实际上是缓存过的, 再次执行同一个RUN命令的时候Docker会直接使用缓存过的运行结果.
然后,如果你需要更新这个Image, 增加一些npm包, 你只需要把 FROM ubuntu:14.04 改为 FROM developerworks/ubuntu-nodejs-runtime, 删除所有RUN指令, 并添加 RUN npm install -g forever, 新的Dockerfile如下:
1 | FROM developerworks/ubuntu-nodejs-runtime MAINTAINER developerworks RUN npm install -g forever |
执行:
1 | root@localhost:~/images# docker build -t="developerworks/ubuntu-nodejs-runtime:add-forever" . Sending build context to Docker daemon 2.56 kB Sending build context to Docker daemon Step 0 : FROM developerworks/ubuntu-nodejs-runtime ---> 2c01d3956f80 Step 1 : MAINTAINER developerworks ---> Running in 24f1d1115c7d ---> 22218cb058df Removing intermediate container 24f1d1115c7d Step 2 : RUN npm install -g forever ---> Running in 4278228003b9 npm WARN engine hawk@0.10.2: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine hawk@0.10.2: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine hawk@0.10.2: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine hoek@0.7.6: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine boom@0.3.8: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine cryptiles@0.1.3: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine sntp@0.1.4: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine hoek@0.7.6: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine boom@0.3.8: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine cryptiles@0.1.3: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine sntp@0.1.4: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine hoek@0.7.6: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine boom@0.3.8: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine cryptiles@0.1.3: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) npm WARN engine sntp@0.1.4: wanted: {"node":"0.8.x"} (current: {"node":"0.10.31","npm":"1.4.23"}) /usr/local/bin/forever -> /usr/local/lib/node_modules/forever/bin/forever /usr/local/bin/foreverd -> /usr/local/lib/node_modules/forever/bin/foreverd forever@0.11.1 /usr/local/lib/node_modules/forever ├── watch@0.8.0 ├── colors@0.6.2 ├── pkginfo@0.3.0 ├── timespan@2.3.0 ├── nssocket@0.5.1 (eventemitter2@0.4.14, lazy@1.0.11) ├── optimist@0.6.1 (wordwrap@0.0.2, minimist@0.0.10) ├── utile@0.2.1 (deep-equal@0.2.1, rimraf@2.2.8, ncp@0.4.2, async@0.2.10, i@0.3.2, mkdirp@0.5.0) ├── nconf@0.6.9 (ini@1.2.1, async@0.2.9, optimist@0.6.0) ├── cliff@0.1.8 (eyes@0.1.8, winston@0.6.2) ├── winston@0.7.3 (cycle@1.0.3, stack-trace@0.0.9, async@0.2.10, eyes@0.1.8, request@2.16.6) ├── flatiron@0.3.11 (optimist@0.6.0, director@1.1.10, prompt@0.2.11, broadway@0.2.9) └── forever-monitor@1.2.3 (watch@0.5.1, minimatch@0.2.14, utile@0.1.7, ps-tree@0.0.3, broadway@0.2.9) ---> f51d8fe3e51d Removing intermediate container 4278228003b9 Successfully built f51d8fe3e51d |
到此,通过Docker搭建一个Node.js的运行环境全部完成, 可以通过本文提供的基本过程进行扩展,满足你自己的需要.
删除镜像
1 | docker rmi <IMAGE ID> |
删除所有容器和镜像
本文要做的实验全部完成,删除全部容器和镜像(建议保留官方的ubuntu:14.04镜像,200多MB, 下载需要时间, 由于我是在服务器上测试, 网速不是问题, 所以为了节约磁盘空间,全删除.
1 | #!/bin/bash # Delete all containers docker rm $(docker ps -a -q) # Delete all images docker rmi $(docker images -q) |
设置镜像标记
命令行帮助
1 | root@localhost:~/images# docker tag Usage: docker tag [OPTIONS] IMAGE[:TAG] [REGISTRYHOST/][USERNAME/]NAME[:TAG] Tag an image into a repository -f, --force=false Force |
测试,查看两次docker images的输出差异
1 | root@localhost:~/images# docker images |
1 | REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE developerworks/ubuntu-nodejs-runtime add-forever f51d8fe3e51d 41 minutes ago 573.9 MB developerworks/ubuntu-trusy-build-essential-4 latest 2c01d3956f80 About an hour ago 562.3 MB developerworks/ubuntu-nodejs-runtime latest 2c01d3956f80 About an hour ago 562.3 MB ubuntu 14.04 c4ff7513909d 2 weeks ago 213 MB |
1 | root@localhost:~/images# docker tag f51d8fe3e51d developerworks/ubuntu-nodejs-runtime-v1 root@localhost:~/images# docker images |
1 | REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE developerworks/ubuntu-nodejs-runtime add-forever f51d8fe3e51d 42 minutes ago 573.9 MB # 下面一行是我们刚加的标记 developerworks/ubuntu-nodejs-runtime-v1 latest f51d8fe3e51d 42 minutes ago 573.9 MB developerworks/ubuntu-trusy-build-essential-4 latest 2c01d3956f80 About an hour ago 562.3 MB developerworks/ubuntu-nodejs-runtime latest 2c01d3956f80 About an hour ago 562.3 MB ubuntu 14.04 c4ff7513909d 2 weeks ago 213 MB |
发布一个镜像到Docker Hub
1 | developerworks/ubuntu-nodejs-runtime-v1 2014/08/31 13:52:00 Error: Status 403 trying to push repository developerworks/ubuntu-nodejs-runtime-v1: "Access denied, you don't have access to this repo" |
这个错误是因为,这不是一个受信任的镜像, 意思就是官方不知道你在镜像里面加了什么东西, 为了防止有人加后门程序, 官方提供了Automated Build功能. 要使用Automated Build功能,需要有一个Github或Bitbucket账号,创建一个仓库, 仓库的根目录下保存Dockerfile文件.
进入此链接, https://registry.hub.docker.com/builds/add, 会引导你完成Github或Bitbucket和Docker仓库的关联.按提示做就可以了.
创建自己的私有仓库
1 | docker run -p 5000:5000 registry |