前言

镜像(image)是 docker 中的三大核心要素之一,是我们必须要掌握的内容.

先来瞄一眼跟镜像相关的命令帮助:

docker image --help
# 通常会输出

Usage:  docker image COMMAND

Manage images

Options:
      --help   Print usage

Commands:
  build       Build an image from a Dockerfile
  history     Show the history of an image
  import      Import the contents from a tarball to create a filesystem image
  inspect     Display detailed information on one or more images
  load        Load an image from a tar archive or STDIN
  ls          List images
  prune       Remove unused images
  pull        Pull an image or a repository from a registry
  push        Push an image or a repository to a registry
  rm          Remove one or more images
  save        Save one or more images to a tar archive (streamed to STDOUT by default)
  tag         Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

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

Docker 镜像命令实践

搜索镜像

类比:我们想玩一个游戏,我们需要先去搜索下

# 搜索远程仓库中的 nginx 镜像
docker search nginx
# 通常会输出
NAME                          DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
nginx                         Official build of Nginx.                        6217      [OK]
jwilder/nginx-proxy           Automated Nginx reverse proxy for docker c...   1051                 [OK]
richarvey/nginx-php-fpm       Container running Nginx + PHP-FPM capable ...   388                  [OK]
webdevops/php-nginx           Nginx with PHP-FPM                              80                   [OK]
million12/nginx-php           Nginx + PHP-FPM 5.5, 5.6, 7.0 (NG), CentOS...   77                   [OK]
h3nrik/nginx-ldap             NGINX web server with LDAP/AD, SSL and pro...   38                   [OK]
bitnami/nginx                 Bitnami nginx Docker Image                      30                   [OK]
evild/alpine-nginx            Minimalistic Docker image with Nginx            16                   [OK]
funkygibbon/nginx-pagespeed   nginx + ngx_pagespeed + openssl on docker-...   11                   [OK]
webdevops/nginx               Nginx container                                 7                    [OK]
webdevops/php-nginx-dev       PHP with Nginx for Development (eg. with x...   6                    [OK]
# ...
# Tips:这里需要关注的是*OFFICIAL*,代表该镜像是官方的.

拉取镜像

类比:我们搜索到想要的游戏,然后需要把游戏的安装包下载过来

# 拉取名为 nginx 的镜像到本地
docker pull nginx
# 通常会输出

查看镜像

类比:游戏的安装包下载完成/要安装游戏时,我们可以看下本机已经有哪些游戏的安装包.

# 拉取完成/要使用镜像时,我们可以看下本机已经有哪些镜像
docker image list
# 通常会输出
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
nginx               latest              958a7ae9e569        2 weeks ago         109MB
# ...
# Tips:这里的镜像名称和镜像ID是我们通常要关注的,因为经常会需要使用它们.

如果需要查看镜像的更多信息,可以试试docker inspect命令:

docker inspect imageId/imageName
# 通常会输出

删除镜像

类比:我们不需要某个游戏安装包了,我们可以把它删除,以节省磁盘空间,看的也清爽点

# 移除一个镜像
docker image remove imageId/imageName 

# 移除多个镜像
# 这里删除2个镜像
docker image remove image1Id/image1Name image2Id/image2Name

待续...