容器使用
获取镜像
如果我们本地没有 ubuntu 镜像，我们可以使用 docker pull 命令来载入 ubuntu 镜像：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker pull ubuntu</span>
启动容器
以下命令使用 ubuntu 镜像启动一个容器，参数为以命令行模式进入该容器：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker run </span><span class="pun">-</span><span class="pln">it ubuntu </span><span class="pun">/</span><span class="pln">bin</span><span class="pun">/</span><span class="pln">bash</span>
参数说明：
- -i: 交互式操作。
- -t: 终端。
- ubuntu: ubuntu 镜像。
- /bin/bash：放在镜像名后的是命令，这里我们希望有个交互式 Shell，因此用的是 /bin/bash。
要退出终端，直接输入 exit:
<pre class="prettyprint prettyprinted"><span class="pln">root@ed09e4490c57</span><span class="pun">:/#</span> <span class="kwd">exit</span>
启动已停止运行的容器
查看所有的容器命令如下：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker ps </span><span class="pun">-</span><span class="pln">a</span>
点击图片查看大图：
使用 docker start 启动一个已停止的容器：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker start b750bbbcfd88 </span>
后台运行
在大部分的场景下，我们希望 docker 的服务是在后台运行的，我们可以过 -d 指定容器的运行模式。
<pre class="prettyprint prettyprinted"><span class="pln">$ docker run </span><span class="pun">-</span><span class="pln">itd </span><span class="pun">--</span><span class="pln">name ubuntu</span><span class="pun">-</span><span class="pln">test ubuntu </span><span class="pun">/</span><span class="pln">bin</span><span class="pun">/</span><span class="pln">bash</span>
点击图片查看大图：
注：加了 -d 参数默认不会进入容器，想要进入容器需要使用指令 docker exec（下面会介绍到）。
停止一个容器
停止容器的命令如下：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker stop </span><span class="pun"><容器</span><span class="pln"> ID</span><span class="pun">></span>
停止的容器可以通过 docker restart 重启：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker restart </span><span class="pun"><容器</span><span class="pln"> ID</span><span class="pun">></span>
进入容器
在使用 -d 参数时，容器启动后会进入后台。此时想要进入容器，可以通过以下指令进入：
- docker attach
- docker exec：推荐大家使用 docker exec 命令，因为此退出容器终端，不会导致容器的停止。
attach 命令
下面演示了使用 docker attach 命令。
<pre class="prettyprint prettyprinted"><span class="pln">$ docker attach </span><span class="lit">1e560fca3906</span>
注意： 如果从这个容器退出，会导致容器的停止。
exec 命令
下面演示了使用 docker exec 命令。
<pre class="prettyprint prettyprinted"><span class="pln">docker </span><span class="kwd">exec</span> <span class="pun">-</span><span class="pln">it </span><span class="lit">243c32535da7</span> <span class="pun">/</span><span class="pln">bin</span><span class="pun">/</span><span class="pln">bash</span>
注意： 如果从这个容器退出，容器不会停止，这就是为什么推荐大家使用 docker exec 的原因。
更多参数说明请使用 docker exec –help 命令查看。
导出和导入容器
导出容器
如果要导出本地某个容器，可以使用 docker export 命令。
<pre class="prettyprint prettyprinted"><span class="pln">$ docker </span><span class="kwd">export</span> <span class="lit">1e560fca3906</span> <span class="pun">></span><span class="pln"> ubuntu</span><span class="pun">.</span><span class="pln">tar</span>
导出容器 1e560fca3906 快照到本地文件 ubuntu.tar。
这样将导出容器快照到本地文件。
导入容器快照
可以使用 docker import 从容器快照文件中再导入为镜像，以下实例将快照文件 ubuntu.tar 导入到镜像 test/ubuntu:v1:
<pre class="prettyprint prettyprinted"><span class="pln">$ cat docker</span><span class="pun">/</span><span class="pln">ubuntu</span><span class="pun">.</span><span class="pln">tar </span><span class="pun">|</span><span class="pln"> docker </span><span class="kwd">import</span> <span class="pun">-</span><span class="pln"> test</span><span class="pun">/</span><span class="pln">ubuntu</span><span class="pun">:</span><span class="pln">v1</span>
此外，也可以通过指定 URL 或者某个目录来导入，例如：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker </span><span class="kwd">import</span><span class="pln"> http</span><span class="pun">:</span><span class="com">//example.com/exampleimage.tgz example/imagerepo</span>
删除容器
删除容器使用 docker rm 命令：
<pre class="prettyprint prettyprinted"><span class="pln">$ docker rm </span><span class="pun">-</span><span class="pln">f </span><span class="lit">1e560fca3906</span>
下面的命令可以清理掉所有处于终止状态的容器。
$ docker container prune
运行一个 web 应用
前面我们运行的容器并没有一些什么特别的用处。
接下来让我们尝试使用 docker 构建一个 web 应用程序。
我们将在docker容器中运行一个 Python Flask 应用来运行一个web应用。
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~#</span><span class="pln"> docker pull training</span><span class="pun">/</span><span class="pln">webapp </span><span class="com"># 载入镜像</span><span class="pln">
runoob@runoob</span><span class="pun">:~#</span><span class="pln"> docker run </span><span class="pun">-</span><span class="pln">d </span><span class="pun">-</span><span class="pln">P training</span><span class="pun">/</span><span class="pln">webapp python app</span><span class="pun">.</span><span class="pln">py</span>
参数说明:
- -d:让容器在后台运行。
- -P:将容器内部使用的网络端口随机映射到我们使用的主机上。
查看 WEB 应用容器
使用 docker ps 来查看我们正在运行的容器：
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~#</span><span class="pln"> docker ps
CONTAINER ID IMAGE COMMAND </span><span class="pun">...</span><span class="pln"> PORTS
d3d5e39ed9d3 training</span><span class="pun">/</span><span class="pln">webapp </span><span class="str">"python app.py"</span> <span class="pun">...</span> <span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">32769</span><span class="pun">-></span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp</span>
这里多了端口信息。
<pre class="prettyprint prettyprinted"><span class="pln">PORTS
</span><span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">32769</span><span class="pun">-></span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp</span>
Docker 开放了 5000 端口（默认 Python Flask 端口）映射到主机端口 32769 上。
这时我们可以通过浏览器访问WEB应用
我们也可以通过 -p 参数来设置不一样的端口：
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker run </span><span class="pun">-</span><span class="pln">d </span><span class="pun">-</span><span class="pln">p </span><span class="lit">5000</span><span class="pun">:</span><span class="lit">5000</span><span class="pln"> training</span><span class="pun">/</span><span class="pln">webapp python app</span><span class="pun">.</span><span class="pln">py</span>
docker ps查看正在运行的容器
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~#</span><span class="pln"> docker ps
CONTAINER ID IMAGE PORTS NAMES
bf08b7f2cd89 training</span><span class="pun">/</span><span class="pln">webapp </span><span class="pun">...</span> <span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">5000</span><span class="pun">-></span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp wizardly_chandrasekhar
d3d5e39ed9d3 training</span><span class="pun">/</span><span class="pln">webapp </span><span class="pun">...</span> <span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">32769</span><span class="pun">-></span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp xenodochial_hoov</span>
容器内部的 5000 端口映射到我们本地主机的 5000 端口上。
网络端口的快捷方式
通过 docker ps 命令可以查看到容器的端口映射，docker 还提供了另一个快捷方式 docker port，使用 docker port 可以查看指定 （ID 或者名字）容器的某个确定端口映射到宿主机的端口号。
上面我们创建的 web 应用容器 ID 为 bf08b7f2cd89 名字为 wizardly_chandrasekhar。
我可以使用 docker port bf08b7f2cd89 或 docker port wizardly_chandrasekhar 来查看容器端口的映射情况。
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker port bf08b7f2cd89
</span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp </span><span class="pun">-></span> <span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">5000</span>
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker port wizardly_chandrasekhar
</span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp </span><span class="pun">-></span> <span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">5000</span>
查看 WEB 应用程序日志
docker logs [ID或者名字] 可以查看容器内部的标准输出。
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker logs </span><span class="pun">-</span><span class="pln">f bf08b7f2cd89
</span><span class="pun">*</span> <span class="typ">Running</span><span class="pln"> on http</span><span class="pun">:</span><span class="com">//0.0.0.0:5000/ (Press CTRL+C to quit)</span>
<span class="lit">192.168</span><span class="pun">.</span><span class="lit">239.1</span> <span class="pun">-</span> <span class="pun">-</span> <span class="pun">[</span><span class="lit">09</span><span class="pun">/</span><span class="typ">May</span><span class="pun">/</span><span class="lit">2016</span> <span class="lit">16</span><span class="pun">:</span><span class="lit">30</span><span class="pun">:</span><span class="lit">37</span><span class="pun">]</span> <span class="str">"GET / HTTP/1.1"</span> <span class="lit">200</span> <span class="pun">-</span>
<span class="lit">192.168</span><span class="pun">.</span><span class="lit">239.1</span> <span class="pun">-</span> <span class="pun">-</span> <span class="pun">[</span><span class="lit">09</span><span class="pun">/</span><span class="typ">May</span><span class="pun">/</span><span class="lit">2016</span> <span class="lit">16</span><span class="pun">:</span><span class="lit">30</span><span class="pun">:</span><span class="lit">37</span><span class="pun">]</span> <span class="str">"GET /favicon.ico HTTP/1.1"</span> <span class="lit">404</span> <span class="pun">-</span>
-f: 让 docker logs 像使用 tail -f 一样来输出容器内部的标准输出。
从上面，我们可以看到应用程序使用的是 5000 端口并且能够查看到应用程序的访问日志。
查看WEB应用程序容器的进程
我们还可以使用 docker top 来查看容器内部运行的进程
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker top wizardly_chandrasekhar
UID PID PPID </span><span class="pun">...</span><span class="pln"> TIME CMD
root </span><span class="lit">23245</span> <span class="lit">23228</span> <span class="pun">...</span> <span class="lit">00</span><span class="pun">:</span><span class="lit">00</span><span class="pun">:</span><span class="lit">00</span><span class="pln"> python app</span><span class="pun">.</span><span class="pln">py</span>
检查 WEB 应用程序
使用 docker inspect 来查看 Docker 的底层信息。它会返回一个 JSON 文件记录着 Docker 容器的配置和状态信息。
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker inspect wizardly_chandrasekhar
</span><span class="pun">[</span>
<span class="pun">{</span>
<span class="str">"Id"</span><span class="pun">:</span> <span class="str">"bf08b7f2cd897b5964943134aa6d373e355c286db9b9885b1f60b6e8f82b2b85"</span><span class="pun">,</span>
<span class="str">"Created"</span><span class="pun">:</span> <span class="str">"2018-09-17T01:41:26.174228707Z"</span><span class="pun">,</span>
<span class="str">"Path"</span><span class="pun">:</span> <span class="str">"python"</span><span class="pun">,</span>
<span class="str">"Args"</span><span class="pun">:</span> <span class="pun">[</span>
<span class="str">"app.py"</span>
<span class="pun">],</span>
<span class="str">"State"</span><span class="pun">:</span> <span class="pun">{</span>
<span class="str">"Status"</span><span class="pun">:</span> <span class="str">"running"</span><span class="pun">,</span>
<span class="str">"Running"</span><span class="pun">:</span> <span class="kwd">true</span><span class="pun">,</span>
<span class="str">"Paused"</span><span class="pun">:</span> <span class="kwd">false</span><span class="pun">,</span>
<span class="str">"Restarting"</span><span class="pun">:</span> <span class="kwd">false</span><span class="pun">,</span>
<span class="str">"OOMKilled"</span><span class="pun">:</span> <span class="kwd">false</span><span class="pun">,</span>
<span class="str">"Dead"</span><span class="pun">:</span> <span class="kwd">false</span><span class="pun">,</span>
<span class="str">"Pid"</span><span class="pun">:</span> <span class="lit">23245</span><span class="pun">,</span>
<span class="str">"ExitCode"</span><span class="pun">:</span> <span class="lit">0</span><span class="pun">,</span>
<span class="str">"Error"</span><span class="pun">:</span> <span class="str">""</span><span class="pun">,</span>
<span class="str">"StartedAt"</span><span class="pun">:</span> <span class="str">"2018-09-17T01:41:26.494185806Z"</span><span class="pun">,</span>
<span class="str">"FinishedAt"</span><span class="pun">:</span> <span class="str">"0001-01-01T00:00:00Z"</span>
<span class="pun">},</span>
<span class="pun">......</span>
停止 WEB 应用容器
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker stop wizardly_chandrasekhar
wizardly_chandrasekhar</span>
重启WEB应用容器
已经停止的容器，我们可以使用命令 docker start 来启动。
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker start wizardly_chandrasekhar
wizardly_chandrasekhar</span>
docker ps -l 查询最后一次创建的容器：
<pre class="prettyprint prettyprinted"><span class="com"># docker ps -l </span><span class="pln">
CONTAINER ID IMAGE PORTS NAMES
bf08b7f2cd89 training</span><span class="pun">/</span><span class="pln">webapp </span><span class="pun">...</span> <span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">5000</span><span class="pun">-></span><span class="lit">5000</span><span class="pun">/</span><span class="pln">tcp wizardly_chandrasekhar</span>
正在运行的容器，我们可以使用 docker restart 命令来重启。
移除WEB应用容器
我们可以使用 docker rm 命令来删除不需要的容器
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker rm wizardly_chandrasekhar
wizardly_chandrasekhar</span>
删除容器时，容器必须是停止状态，否则会报如下错误
<pre class="prettyprint prettyprinted"><span class="pln">runoob@runoob</span><span class="pun">:~</span><span class="pln">$ docker rm wizardly_chandrasekhar
</span><span class="typ">Error</span><span class="pln"> response </span><span class="kwd">from</span><span class="pln"> daemon</span><span class="pun">:</span> <span class="typ">You</span><span class="pln"> cannot remove a running container bf08b7f2cd897b5964943134aa6d373e355c286db9b9885b1f60b6e8f82b2b85</span><span class="pun">.</span> <span class="typ">Stop</span><span class="pln"> the container before attempting removal </span><span class="kwd">or</span><span class="pln"> force remove</span>