Docker 深入

什么是 Docker ?

Enterprise Container Platform for High-Velocity Innovation
高速创新的企业集装箱平台

Securely build, share and run any application, anywhere
在任何地方安全地构建，共享和运行任何应用程序

什么是容器 ?

容器是一个标准的软件单元，它将代码及其所有依赖关系打包，以便应用程序从一个计算环境快速可靠地运行到另一个计算环境。

Docker安装在原来的博客有讲到,这里就讲Docker的使用及实例

Docker使用

Docker Hello World

[root@caoxl ~]# docker run hello-world

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

Docker 容器使用

Docker 客户端

[root@caoxl ~]# docker

Usage:	docker [OPTIONS] COMMAND

A self-sufficient runtime for containers

Options:
      --config string      Location of client config files (default "/root/.docker")
  -D, --debug              Enable debug mode
  -H, --host list          Daemon socket(s) to connect to
  -l, --log-level string   Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default
                           "info")
      --tls                Use TLS; implied by --tlsverify
      --tlscacert string   Trust certs signed only by this CA (default "/root/.docker/ca.pem")
      --tlscert string     Path to TLS certificate file (default "/root/.docker/cert.pem")
      --tlskey string      Path to TLS key file (default "/root/.docker/key.pem")
      --tlsverify          Use TLS and verify the remote
  -v, --version            Print version information and quit

Management Commands:
  builder     Manage builds
  config      Manage Docker configs
  container   Manage containers
  engine      Manage the docker engine
  image       Manage images
  network     Manage networks
  node        Manage Swarm nodes
  plugin      Manage plugins
  secret      Manage Docker secrets
  service     Manage services
  stack       Manage Docker stacks
  swarm       Manage Swarm
  system      Manage Docker
  trust       Manage trust on Docker images
  volume      Manage volumes

Commands:
  attach      Attach local standard input, output, and error streams to a running container
  build       Build an image from a Dockerfile
  commit      Create a new image from a container's changes
  cp          Copy files/folders between a container and the local filesystem
  create      Create a new container
  diff        Inspect changes to files or directories on a container's filesystem
  events      Get real time events from the server
  exec        Run a command in a running container
  export      Export a container's filesystem as a tar archive
  history     Show the history of an image
  images      List images
  import      Import the contents from a tarball to create a filesystem image
  info        Display system-wide information
  inspect     Return low-level information on Docker objects
  kill        Kill one or more running containers
  load        Load an image from a tar archive or STDIN
  login       Log in to a Docker registry
  logout      Log out from a Docker registry
  logs        Fetch the logs of a container
  pause       Pause all processes within one or more containers
  port        List port mappings or a specific mapping for the container
  ps          List containers
  pull        Pull an image or a repository from a registry
  push        Push an image or a repository to a registry
  rename      Rename a container
  restart     Restart one or more containers
  rm          Remove one or more containers
  rmi         Remove one or more images
  run         Run a command in a new container
  save        Save one or more images to a tar archive (streamed to STDOUT by default)
  search      Search the Docker Hub for images
  start       Start one or more stopped containers
  stats       Display a live stream of container(s) resource usage statistics
  stop        Stop one or more running containers
  tag         Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
  top         Display the running processes of a container
  unpause     Unpause all processes within one or more containers
  update      Update configuration of one or more containers
  version     Show the Docker version information
  wait        Block until one or more containers stop, then print their exit codes

Run 'docker COMMAND --help' for more information on a command.

可以通过命令 docker command --help 更深入的了解指定的 Docker 命令使用方法。

[root@caoxl ~]# docker ps --help

Usage:	docker ps [OPTIONS]

List containers

Options:
  -a, --all             Show all containers (default shows just running)
  -f, --filter filter   Filter output based on conditions provided
      --format string   Pretty-print containers using a Go template
  -n, --last int        Show n last created containers (includes all states) (default -1)
  -l, --latest          Show the latest created container (includes all states)
      --no-trunc        Don't truncate output
  -q, --quiet           Only display numeric IDs
  -s, --size            Display total file sizes

运行一个Web应用

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。

[root@caoxl ~]# docker pull training/webapp
Using default tag: latest
latest: Pulling from training/webapp
e190868d63f8: Pull complete 
909cd34c6fd7: Pull complete 
0b9bfabab7c1: Pull complete 
a3ed95caeb02: Pull complete 
10bbbc0fc0ff: Pull complete 
fca59b508e9f: Pull complete 
e7ae2541b15b: Pull complete 
9dd97ef58ce9: Pull complete 
a4c1b0cb7af7: Pull complete 
Digest: sha256:06e9c1983bd6d5db5fba376ccd63bfa529e8d02f23d5079b8f74a616308fb11d
Status: Downloaded newer image for training/webapp:latest

[root@caoxl ~]# docker run -d -P training/webapp python app.py
fc14b64cda1d2445bcea207ece36b9b274f3a422be26c92bd95cbe1af96d0d6e

• 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映射到我们使用的手机上

查看WEB应用容器

[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE                        COMMAND                  CREATED              STATUS              PORTS                                                                        NAMES
fc14b64cda1d        training/webapp              "python app.py"          About a minute ago   Up About a minute   0.0.0.0:32768->5000/tcp                                                      hopeful_mendel
c4d4afebb0d1        pinguo/php-msf-demo:newdev   "/run.sh /usr/sbin/s…"   27 minutes ago       Up 27 minutes       0.0.0.0:443->443/tcp, 80/tcp, 0.0.0.0:8000->8000/tcp, 0.0.0.0:2202->22/tcp   pinguo_php-msf-demo_newdev

停止Web应用容器,使用NAMES

[root@caoxl ~]# docker stop hopeful_mendel
hopeful_mendel

重启WEB应用容器

[root@caoxl ~]# docker start hopeful_mendel
hopeful_mendel

移除WEB应用容器

[root@caoxl ~]# docker rm hopeful_mendel
hopeful_mendel

删除容器时，容器必须是停止状态，否则会报错误

Docker 镜像使用

列出镜像列表

[root@caoxl ~]# docker images
REPOSITORY                                                    TAG                 IMAGE ID            CREATED             SIZE
hello-world                                                   latest              fce289e99eb9        4 months ago        1.84kB
pinguo/php-msf-demo                                           newdev              39995bac5087        18 months ago       1.54GB
registry.cn-hangzhou.aliyuncs.com/pinguo-ops/php-msf-docker   latest              39995bac5087        18 months ago       1.54GB
training/webapp                                               latest              6fae60ef3446        4 years ago         349MB

• 各个选项说明
  • REPOSITORY: 表示镜像的仓库源
  • TAG: 镜像的标签
  • IMAGE ID: 镜像ID
  • CREATED: 镜像创建时间
  • SIZE: 镜像大小

查找镜像

[root@caoxl ~]# docker pull skiychan/nginx-php7
Using default tag: latest
latest: Pulling from skiychan/nginx-php7
8ba884070f61: Pull complete 
3c273468b2f5: Pull complete 
d2c95013bbb4: Pull complete 
4c3d9a8120f6: Pull complete 
f84b131a51d1: Pull complete 
509155c099f5: Pull complete 
c24ed08ea428: Pull complete 
Digest: sha256:040a3047d85daa7b0f083479dffbc54a034e60e8da0edcc9570047da402c411b
Status: Downloaded newer image for skiychan/nginx-php7:latest

获取一个新的镜像

[root@caoxl ~]# docker pull skiychan/nginx-php7
Using default tag: latest

Docker 容器连接

Docker实例

Docker 安装Nginx

[root@caoxl ~]# docker search nginx
NAME                                                   DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
nginx                                                  Official build of Nginx.                        11403               [OK]                
jwilder/nginx-proxy                                    Automated Nginx reverse proxy for docker con…   1600                                    [OK]
richarvey/nginx-php-fpm                                Container running Nginx + PHP-FPM capable of…   712                                     [OK]
...

• 拉取官方的镜像

[root@caoxl ~]# docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
743f2d6c1f65: Pull complete 
6bfc4ec4420a: Pull complete 
688a776db95f: Pull complete 
Digest: sha256:23b4dcdf0d34d4a129755fc6f52e1c6e23bb34ea011b315d87e193033bcd1b68
Status: Downloaded newer image for nginx:latest

• 以下命令使用 NGINX 默认的配置来启动一个 Nginx 容器实例：

[root@caoxl ~]# docker run --name caoxl -p 8081:80 -d nginx
1e13c99fa213152f2b5220a32254e658f72fd7fc8ce8e6d0a056fe87f74993a2

执行以上命令会生成一串字符串，类似 6dd4380ba70820bd2acc55ed2b326dd8c0ac7c93f68f0067daecad82aef5f938，这个表示容器的 ID，一般可作为日志的文件名。

• --name 容器名称
• -d 设置容器在后台一直运行
• -p 端口进行映射,将本地8081端口映射到容器内部的80端口

[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
1e13c99fa213        nginx               "nginx -g 'daemon of…"   17 seconds ago      Up 16 seconds       0.0.0.0:8081->80/tcp   caoxl

相关命令

• 如果要重新载入 NGINX 可以使用以下命令发送 HUP 信号到容器：

docker kill -s HUP nginx # container-name 容器名称,即docker ps 中的NAMES列

• 重启 Nginx 容器命令

docker restart nginx

• 移除容器

# 移除容器前,需要停止容器
[root@caoxl ~]# docker stop 1e13c99fa213
1e13c99fa213
[root@caoxl ~]# docker rm 1e13c99fa213
1e13c99fa213

# ps 列出运行的容器列表
[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
# ps -a 列出所有容器列表
[root@caoxl ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

Docker 安装PHP

# 先查找php镜像
[root@caoxl ~]# docker search php

# 这里我们拉取官方的镜像,标签为7.2-fpm
[root@caoxl ~]# docker pull php:7.2-fpm
7.2-fpm: Pulling from library/php
743f2d6c1f65: Already exists 
6307e89982cc: Already exists 
807218e72ce2: Already exists 
5108df1d03f8: Already exists 
82ffe3f78be2: Pull complete 
17c66bee581c: Pull complete 
03011f3bcf78: Pull complete 
28b6a4179c3e: Pull complete 
b77fa38a9e9c: Pull complete 
79928611774d: Pull complete 
Digest: sha256:c50c0cffd2af10291d8b8fe3dd410aed3eca302b8163e2ab34cd1bfc6feae495
Status: Downloaded newer image for php:7.2-fpm

Docker 安装MySQL

[root@caoxl ~]# docker search mysql
NAME                                                   DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
mysql                                                  MySQL is a widely used, open-source relation…   8142                [OK]                
mariadb                                                MariaDB is a community-developed fork of MyS…   2771                [OK]  

这里我们拉取官方的镜像,标签为5.7

[root@caoxl ~]# docker pull mysql:5.7
5.7: Pulling from library/mysql
743f2d6c1f65: Already exists 
3f0c413ee255: Pull complete 
aef1ef8f1aac: Pull complete 
f9ee573e34cb: Pull complete 
3f237e01f153: Pull complete 
f9da32e8682a: Pull complete 
4b8da52fb357: Pull complete 
6f38e9cfd49b: Pull complete 
9f4834b3f44f: Pull complete 
af631d92fdba: Pull complete 
0e771ddab25c: Pull complete 
Digest: sha256:196fe3e00d68b2417a8cf13482bdab1fcc2b32cf7c7575d0906c700688b352b4
Status: Downloaded newer image for mysql:5.7

等待下载完成后，我们就可以在本地镜像列表里查到REPOSITORY为mysql,标签为5.6的镜像

[root@caoxl ~]# docker images | grep mysql
mysql                                                         5.7                 7faa3c53e6d6        7 days ago          373MB

Docker 安装Redis

[root@caoxl ~]# docker search redis
NAME                             DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
redis                            Redis is an open source key-value store that…   6900                [OK]                
bitnami/redis                    Bitnami Redis Docker Image                      112                                     [OK]

这里我们拉取官方的镜像,标签为5.0

[root@caoxl ~]# docker pull redis:5.0
5.0: Pulling from library/redis
743f2d6c1f65: Already exists 
171658c5966d: Pull complete 
fbef10bd7a65: Pull complete 
98afd60e45e4: Pull complete 
495c87fda859: Pull complete 
ed6767858416: Pull complete 
Digest: sha256:2dfa6432744659268d001d16c39f7be52ee73ef7e1001ff80643f0f7bdee117e
Status: Downloaded newer image for redis:5.0

Docker 命令大全

容器生命周期管理

• run - 创建一个新的容器并运行一个命令

[root@caoxl ~]# docker run --name nginx -d nginx:latest
2b077bf72f07ffa1e4e821f02bced02f9265900cc8c0b4dd663a3f90ebb2e8dc

• start/stop/restart - 启动/停止/重启一个或多个容器

# 启动一个或多个容器
[root@caoxl ~]# docker start caoxl-php
caoxl-php

# 停止一个运行中的容器
[root@caoxl ~]# docker stop nginx
nginx

# 重启一个已经停止的容器
[root@caoxl ~]# docker restart nginx
nginx

• kill - 杀掉一个运行中的容器

# 杀掉一个运行中的容器
[root@caoxl ~]# docker kill -s KILL nginx
nginx

• rm - 删除一个或多个容器(需先停止容器)

# 删除一个或多个容器(需先停止容器)
[root@caoxl ~]# docker rm ade302349866
Error response from daemon: You cannot remove a running container ade30234986633c113e9b1e5828d6e6e1f8f74c47cdb878674cec1a2e4a7db3d. Stop the container before attempting removal or force remove

# 强制删除
[root@caoxl ~]# docker rm -f ade302349866
ade302349866

参数说明:

• -f: 通过SIGKILL信号强制删除一个运行中的容器
• -l: 移除容器间的网络连接,而非容器本身
• -v: 删除与容器关联的卷

• pasue/unpause - 暂停/恢复容器中的进程

[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
9bf46c51c287        nginx               "nginx -g 'daemon of…"   34 minutes ago      Up 34 minutes       0.0.0.0:8081->80/tcp   caoxl-nginx

# 暂停容器中的进程
[root@caoxl ~]# docker pause caoxl-nginx
caoxl-nginx

[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                   PORTS                  NAMES
9bf46c51c287        nginx               "nginx -g 'daemon of…"   36 minutes ago      Up 36 minutes (Paused)   0.0.0.0:8081->80/tcp   caoxl-nginx

# 恢复容器中的进程
[root@caoxl ~]# docker unpause caoxl-nginx
caoxl-nginx

• create - 创建一个新的容器但不启动

[root@caoxl ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
redis               5.0                 a4fe14ff1981        7 days ago          95MB
php                 7.2-fpm             0be748e55df6        7 days ago          366MB
nginx               latest              53f3fd8007f7        7 days ago          109MB
mysql               5.7                 7faa3c53e6d6        7 days ago          373MB

# 创建一个新的容器但不启动
[root@caoxl ~]# docker create --name caoxl-mysql mysql:5.7
2af5be371c1586be55e6d80cbd1991c029fa44e2306fe2a22956c876fde5ee38

[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
9bf46c51c287        nginx               "nginx -g 'daemon of…"   39 minutes ago      Up 39 minutes       0.0.0.0:8081->80/tcp   caoxl-nginx

[root@caoxl ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                       PORTS                  NAMES
2af5be371c15        mysql:5.7           "docker-entrypoint.s…"   10 seconds ago      Created                                             caoxl-mysql
2b077bf72f07        nginx:latest        "nginx -g 'daemon of…"   13 minutes ago      Exited (137) 7 minutes ago                          nginx
9bf46c51c287        nginx               "nginx -g 'daemon of…"   39 minutes ago      Up 39 minutes                0.0.0.0:8081->80/tcp   caoxl-nginx

• exec - 在运行中的容器中执行命令

# 在运行中的容器中执行命令
[root@caoxl ~]# docker exec -i -t nginx /bin/bash
root@2b077bf72f07:/# ls
bin  boot  dev	etc  home  lib	lib64  media  mnt  opt	proc  root  run  sbin  srv  sys  tmp  usr  var

容器操作

• ps - 列出容器

[root@caoxl ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
2b077bf72f07        nginx:latest        "nginx -g 'daemon of…"   18 minutes ago      Up 2 minutes        80/tcp                 nginx
9bf46c51c287        nginx               "nginx -g 'daemon of…"   44 minutes ago      Up 43 minutes       0.0.0.0:8081->80/tcp   caoxl-nginx

参数说明:

• -a: 显示所有容器,包括未运行的
• -f: 根据条件过滤显示的内容
• -l: 显示最近创建的容器
• -n: 显示最近创建的n个容器
• -q: 静默模式,只显示容器编号
• -s: 显示总的文件大小

• inspect - 获取容器/镜像的元数据

[root@caoxl ~]# docker inspect nginx
[
    {
        "Id": "2b077bf72f07ffa1e4e821f02bced02f9265900cc8c0b4dd663a3f90ebb2e8dc",
        "Created": "2019-05-15T07:20:48.265101617Z",
...

• top - 查看容器中运行的进程信息

[root@caoxl ~]# docker top nginx
UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
root                27933               27916               0                   15:36               ?                   00:00:00            nginx: master process nginx -g daemon off;
101                 27965               27933               0                   15:36               ?                   00:00:00            nginx: worker process

# 查看所有运行容器的进程信息
for i in  `docker ps |grep Up|awk '{print $1}'`;do echo \ &&docker top $i; done

• attach - 连接到正在运行的容器

[root@caoxl ~]# docker attach --sig-proxy=false nginx

• logs - 获取容器的日志

[root@caoxl ~]# docker logs -f nginx

# 查看容器nginx从2019年5月15后的最新10条日志
[root@caoxl ~]# docker logs --since="2019-05-15" --tail=10 nginx

• port - 列出指定的容器的端口映射，或者查找将PRIVATE_PORT NAT到面向公众的端口。

[root@caoxl ~]# docker port caoxl-nginx
80/tcp -> 0.0.0.0:8081

容器rootfs命令

• commit - 从容器创建一个新的镜像

# 从容器创建一个新的镜像
[root@caoxl ~]# docker commit -a "caoxl" -m "docker commit" f1069837f3eb redis:commit
sha256:2d77296f02fa8a37890e686a5bc07f4173229044bc53f811b4821244f5db3563

[root@caoxl ~]# docker images | grep redis
redis               commit              2d77296f02fa        19 seconds ago      95MB
redis               5.0                 a4fe14ff1981        7 days ago          95MB
redis               latest              a4fe14ff1981        7 days ago          95MB

• cp - 用于容器和主机直接的数据拷贝

# 将主机/var/www目录拷贝到容器f1069837f3eb的/www目录下。
[root@caoxl ~]# docker cp /var/www f1069837f3eb:/www/

镜像仓库

• login/logout - 登陆/退出一个Docker镜像仓库,默认为官方仓库 Docker Hub

前往Docker Hub,注册账号.

# 登陆
[root@caoxl ~]# docker login -u username -p password
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store

Login Succeeded

# 登出
[root@caoxl ~]# docker logout
Removing login credentials for https://index.docker.io/v1/

• pull - 从镜像仓库中拉取或者更新指定镜像

[root@caoxl ~]# docker pull swoft/swoft

• push - 将本地的镜像上传到镜像仓库,要先登陆到镜像仓库

[root@caoxl ~]# docker push php:7.2-fpm
The push refers to repository [docker.io/library/php]

• search - 从Docker Hub查找镜像

root@caoxl ~]# docker search swoole
NAME                          DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
xlight/docker-php7-swoole     php7-cli with swoole                            28                                      [OK]
twosee/swoole-coroutine       Perfect Swoole Dockerfile for senior develop…   27                                      [OK]
kong36088/nginx-php7-swoole   nginx+php7+swoole拓展，另外自带redis和memcac…           14                                      
...

本地镜像管理

• images - 列出本地镜像

[root@caoxl ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
redis               5.0                 a4fe14ff1981        7 days ago          95MB
php                 7.2-fpm             0be748e55df6        7 days ago          366MB
nginx               latest              53f3fd8007f7        7 days ago          109MB
mysql               5.7                 7faa3c53e6d6        7 days ago          373MB
swoft/swoft         latest              493b8cc21299        3 months ago        447MB

• rmi - 删除本地一个或多个镜像

[root@caoxl ~]# docker rmi 2d77296f02fa
Untagged: redis:commit
Deleted: sha256:2d77296f02fa8a37890e686a5bc07f4173229044bc53f811b4821244f5db3563

参数说明:

• -f: 强制删除
• --no-prune: 不移除该镜像的过程镜像,默认移除

• tag - 标记本地镜像,将其归入某一个仓库

[root@caoxl ~]# docker tag swoft/swoft:latest swoft/swoft:swoft
[root@caoxl ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
swoft/swoft         latest              493b8cc21299        3 months ago        447MB
swoft/swoft         swoft               493b8cc21299        3 months ago        447MB

• history - 查看指定镜像的创建历史

# 查看本地镜像nginx的创建历史
[root@caoxl ~]# docker history nginx
IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
53f3fd8007f7        7 days ago          /bin/sh -c #(nop)  CMD ["nginx" "-g" "daemon…   0B                  
<missing>           7 days ago          /bin/sh -c #(nop)  STOPSIGNAL SIGTERM           0B                  
<missing>           7 days ago          /bin/sh -c #(nop)  EXPOSE 80                    0B                  
<missing>           7 days ago          /bin/sh -c ln -sf /dev/stdout /var/log/nginx…   22B                 
<missing>           7 days ago          /bin/sh -c set -x  && apt-get update  && apt…   54.1MB              
<missing>           7 days ago          /bin/sh -c #(nop)  ENV NJS_VERSION=1.15.12.0…   0B                  
<missing>           7 days ago          /bin/sh -c #(nop)  ENV NGINX_VERSION=1.15.12…   0B                  
<missing>           7 days ago          /bin/sh -c #(nop)  LABEL maintainer=NGINX Do…   0B                  
<missing>           7 days ago          /bin/sh -c #(nop)  CMD ["bash"]                 0B                  
<missing>           7 days ago          /bin/sh -c #(nop) ADD file:fcb9328ea4c115670…   55.3MB 

info|version

• info - 显示Docker系统信息,包括镜像和容器数

# 查看Docker系统信息
[root@caoxl ~]# docker info
Containers: 5
 Running: 4
 Paused: 0
 Stopped: 1
Images: 5
...

• version - 显示Docker版本信息

[root@caoxl ~]# docker version
Client:
 Version:           18.09.6
 API version:       1.39
 Go version:        go1.10.8
 Git commit:        481bc77156
 Built:             Sat May  4 02:34:58 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.6
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.8
  Git commit:       481bc77
  Built:            Sat May  4 02:02:43 2019
  OS/Arch:          linux/amd64
  Experimental:     false

常见问题

image is referenced in multiple repositories

• 查看镜像

[root@caoxl ~]# docker images
REPOSITORY                                                    TAG                 IMAGE ID            CREATED             SIZE
php                                                           7.2-fpm             0be748e55df6        7 days ago          366MB
nginx                                                         latest              53f3fd8007f7        7 days ago          109MB
mysql                                                         5.7                 7faa3c53e6d6        7 days ago          373MB
pinguo/php-msf-demo                                           newdev              39995bac5087        18 months ago       1.54GB
registry.cn-hangzhou.aliyuncs.com/pinguo-ops/php-msf-docker   latest              39995bac5087        18 months ago       1.54GB

• 删除镜像

[root@caoxl ~]# docker rmi 39995bac5087
Error response from daemon: conflict: unable to delete 39995bac5087 (must be forced) - image is referenced in multiple repositories

仔细观察，发现39995bac5087这个镜像id指向了两个repository，因此无法删除

• 删除时可以用repository和tag的方式来删除

[root@caoxl ~]# docker rmi pinguo/php-msf-demo:newdev
Untagged: pinguo/php-msf-demo:newdev
Deleted: sha256:39995bac5087fa922c2eed5f75ae55fce3b08a0d691cd200d5c1c2879660398f
....

• 再次查看镜像

[root@caoxl ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
php                 7.2-fpm             0be748e55df6        7 days ago          366MB
nginx               latest              53f3fd8007f7        7 days ago          109MB
mysql               5.7                 7faa3c53e6d6        7 days ago          373MB

Docker 资源汇总

Docker官方英文资源

• Docker官网
• Docker Windows 入门
• Docker CE(社区版) CentOs
• Docker mac 入门
• Docker 用户指引
• Docker 官方博客
• Docker Hub
• Docker开源

Docker国内镜像

• 阿里云官方镜像加速: https://help.aliyun.com/document_detail/60750.html
• 网易加速器: http://hub-mirror.c.163.com

参考

• Docker
• Docker 教程