docker镜像
一、镜像概念
前置操作拉取镜像：
# 拉取镜像
# 拉取最新版本的镜像
[root@hqs ~]# docker pull ubuntu
Using default tag: latest
latest: Pulling from library/ubuntu
7c3b88808835: Already exists
Digest: sha256:8ae9bafbb64f63a50caab98fd3a5e37b3eb837a3e0780b78e5218e63193961f9
Status: Downloaded newer image for ubuntu:latest
docker.io/library/ubuntu:latest
# 拉取指定版本镜像
[root@hecs-hqs-01 ~]# docker pull ubuntu:14.04
14.04: Pulling from library/ubuntu
2e6e20c8e2e6: Pull complete
0551a797c01d: Pull complete
512123a864da: Pull complete
Digest: sha256:60840958b25b5947b11d7a274274dc48ab32a2f5d18527f5dae2962b64269a3a
Status: Downloaded newer image for ubuntu:14.04
docker.io/library/ubuntu:14.04
二、镜像查看
1、镜像查看示例
# 语法
[root@bruce ~]# docker images -h
Flag shorthand -h has been deprecated, please use --help
Usage: docker images [OPTIONS] [REPOSITORY[:TAG]]
List images # 展示镜像列表
Aliases:
docker image ls, docker image list, docker images
Options:
-a, --all Show all images (default hides intermediate images) # 显示所有镜像（默认隐藏中间镜像）
--digests Show digests # 显示镜像的摘要值（由哈希函数sha256计算得出）
-f, --filter filter Filter output based on conditions provided # 根据条件过滤输出（dangling、label、since、before、reference）
--format string Format output using a custom template: # 指定返回值的模板文件
'table': Print output in table format with column headers (default)
'table TEMPLATE': Print output in table format using the given Go template
'json': Print in JSON format
'TEMPLATE': Print output using the given Go template.
Refer to https://docs.docker.com/go/formatting/ for more information about formatting output with templates
--no-trunc Don t truncate output # 完整输出
-q, --quiet Only show image IDs # 只显示ID值
# 查看本地主机上的镜像
[root@hqs ~]# docker images
镜像仓库 标签 镜像ID 创建时间 镜像大小
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest 54c9d81cbb44 4 weeks ago 72.8MB
ubuntu 14.04 13b66b487594 11 months ago 197MB
hello-world latest feb5d9fea6a5 5 months ago 13.3kB
# 查看本地某个镜像
# 加上--no-trunc显示完整镜像ID：UUID形式表示，64个的十六进制字符
# 实际上镜像ID是镜像的摘要值（Digest），是由哈希函数sha256对镜像配置文件计算而来的
[root@hecs-hqs-01 ~]# docker images ubuntu --no-trunc
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest sha256:54c9d...f704f 4 weeks ago 72.8MB
# 加上--digests选项可以显示镜像摘要值
[root@hqs ~]# docker images ubuntu --digests
镜像仓库 标签 镜像的摘要值 镜像ID 创建时间 镜像大小
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZE
ubuntu latest sha256:8ae9b...3961f9 2b4cba85892a 4 days ago 72.8MB
# 同时输出摘要值和完整镜像id
[root@hqs ~]# docker images ubuntu --digests --no-trunc
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZE
ubuntu latest sha256:8ae9bafbb64f63a50caab98fd3a5e37b3eb837a3e0780b78e5218e63193961f9 sha256:2b4cba85892afc2ad8ce258a8e3d9daa4a1626ba380677cee93ef2338da442ab 4 days ago 72.8MB
ubuntu 14.04 sha256:60840958b25b5947b11d7a274274dc48ab32a2f5d18527f5dae2962b64269a3a sha256:13b66b487594a1f2b75396013bc05d29d9f527852d96c5577cc4f187559875d0 11 months ago 197MB
# format指定返回值模板
# 输出json格式
[root@bruce ~]# docker images --format json
{"Containers":"N/A","CreatedAt":"2021-10-16 08:37:47 +0800 CST","CreatedSince":"16 months ago","Digest":"\u003cnone\u003e","ID":"ba6acccedd29","Repository":"ubuntu","SharedSize":"N/A","Size":"72.8MB","Tag":"latest","UniqueSize":"N/A","VirtualSize":"72.77MB"}
{"Containers":"N/A","CreatedAt":"2021-09-16 02:20:05 +0800 CST","CreatedSince":"17 months ago","Digest":"\u003cnone\u003e","ID":"5d0da3dc9764","Repository":"centos","SharedSize":"N/A","Size":"231MB","Tag":"latest","UniqueSize":"N/A","VirtualSize":"231.2MB"}
# 输出自定义模板格式
[root@bruce ~]# docker images --format "{{.Repository}}:{{.Tag}}"
ubuntu:latest
centos:latest
ubuntu:14.04
centos/httpd:latest
# 只显示ID,方便批量操作
[root@bruce ~]# docker images -q
ba6acccedd29
5d0da3dc9764
13b66b487594
2cc07fbb5000
# 根据条件过滤输出
# dangling：显示标记为空的镜像，值只有true和false
[root@bruce ~]# docker images --filter dangling=true
REPOSITORY TAG IMAGE ID CREATED SIZE
[root@bruce ~]# docker images --filter dangling=false
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest ba6acccedd29 16 months ago 72.8MB
# before:根据时间来进行过滤，某个镜像构建时间之前的镜像列表
[root@bruce ~]# docker images --filter before=5d0da3dc9764
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu 14.04 13b66b487594 23 months ago 196MB
centos/httpd latest 2cc07fbb5000 4 years ago 258MB
# since：跟before正好相反，某个镜像构建之后的镜像列表
[root@bruce ~]# docker images --filter since=5d0da3dc9764
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest ba6acccedd29 16 months ago 72.8MB
# reference：这个是添加正则进行匹配
[root@bruce ~]# docker images --filter reference=*:*
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest ba6acccedd29 16 months ago 72.8MB
centos latest 5d0da3dc9764 17 months ago 231MB
ubuntu 14.04 13b66b487594 23 months ago 196MB
[root@bruce ~]# docker images --filter reference=ubuntu
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest ba6acccedd29 16 months ago 72.8MB
ubuntu 14.04 13b66b487594 23 months ago 196MB
# label：根据标签进行过滤，其中lable的值，是docker在编译的时候配置的或者在Dockerfile中配置的 (需要案例！！！)
[root@bruce ~]# docker images --filter label=hqs
REPOSITORY TAG IMAGE ID CREATED SIZE
2、镜像标识
镜像可以通过镜像ID、镜像名称（含标签）、镜像摘要值来标识或引用。
# 可以用镜像仓库名称:标签来标识镜像
[root@hqs ~]# docker images ubuntu:14.04 --digests
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZE
ubuntu 14.04 <none> 13b66b487594 11 months ago 197MB
[root@localhost ~]# docker rmi ubuntu:14.04
# 可以用镜像id来标识镜像
[root@hqs docker-hello]# docker rmi 2b4cba85892a
Untagged: ubuntu:latest
Untagged: ubuntu@sha256:8ae9bafbb64f63a50caab98fd3a5e37b3eb837a3e0780b78e5218e63193961f9
Deleted: sha256:2b4cba85892afc2ad8ce258a8e3d9daa4a1626ba380677cee93ef2338da442ab
Deleted: sha256:68a85fa9d77ecac87de23805c4be8766bda08a86787e324036cbcf84b62640fa
# 镜像可以通过摘要值作为内容寻址标识符，格式为：仓库名称@摘要
[root@hqs ~]# docker images ubuntu@sha256:8ae9bafbb64f63a50caab98fd3a5e37b3eb837a3e0780b78e5218e63193961f9
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu <none> 2b4cba85892a 4 days ago 72.8MB
# 尝试删除这种方式标识的镜像，只能删除摘要值
[root@localhost ~]# docker rmi ubuntu@sha256:9a0bdde4188b896a372804be2384015e90e3f84906b750c1a53539b585fbbe7f
Untagged: ubuntu@sha256:9a0bdde4188b896a372804be2384015e90e3f84906b750c1a53539b585fbbe7f
[root@localhost ~]# docker images --digests
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZE
ubuntu latest <none> 58db3edaf2be 3 weeks ago 77.8MB
三、镜像描述文件Dockerfile
Docker所用的Dockerfile文件用来描述镜像，定义了如何构建Docker镜像。
Dockerfile是一个文本文件，包含了要构建镜像的所有命令。
Docker通过读取Dockerfile中的指令自动构建镜像。
1、创建hello-world镜像案例
# 1、找一个目录创建目录
[root@hqs hqs]# mkdir docker-hello
# 2、进入这个目录后创建Dockerfile文件：
vi Dockerfile
FROM scratch
COPY hello /
CMD ["/hello"] # 注意：CMD后要空格
# 3、再创建hello.c文件
[root@hqs hqs]# vi hello.c
#include<stdio.h>
void main (){
printf("hello docker\n");
}
# 4、编译hello文件
# 首先安装gcc、glibc-static
yum install -y gcc
yum install -y glibc-static
# 进行编译
[root@hqs docker-hello]# gcc --static hello.c -o hello
[root@hqs docker-hello]# ls
Dockerfile hello hello.c
# 4、基于dockerfile创建镜像
# Dockerfile文件执行build命令来构建镜像
[root@hqs docker-hello]# docker build -t my-hello .
Sending build context to Docker daemon 865.3kB
Step 1/3 : FROM scratch
--->
Step 2/3 : COPY hello /
---> 32b0ccadf376
Step 3/3 : CMD ["/hello"]
---> Running in fc65eb581596
Removing intermediate container fc65eb581596
---> 27f012ef630b
Successfully built 27f012ef630b
Successfully tagged my-hello:latest
# 5、查看镜像
[root@hqs docker-hello]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
my-hello latest 27f012ef630b 44 seconds ago 861kB
# 6、运行镜像
[root@hqs docker-hello]# docker run my-hello
hello docker
2、dockerfile语法初解
父镜像（Parent Image）：该镜像的Dockerfile文件中由FROM指定的镜像。后续指令都应用到这个父镜像中。
基础镜像（Base Image）：不依赖其他镜像，从零开始构建的镜像。如：未提供FROM指令或提供FROM scratch指令所构建的镜像。
FROM scratch # FROM命令定义基础镜像，scratch是空白镜像，表示从零开始构建
COPY hello / # 将文件复制到镜像根目录
CMD ["/hello"] # 镜像启动容器时执行/hello这个可执行文件
四、基于联合文件系统的镜像分层
五、Docker镜像操作命令
docker新版本提供了一个统一的镜像操作命令：docker image.
操作和传统的镜像操作docker子命令相对应，个别语法不一样。
1、拉取镜像
从镜像仓库中下载镜像到本地，一般是保存在/var/lib/docker目录
[root@hqs /]# docker image pull centos
Using default tag: latest
latest: Pulling from library/centos
a1d0c7532777: Pull complete
Digest: sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
Status: Downloaded newer image for centos:latest
docker.io/library/centos:latest
# 传统写法
[root@hecs-hqs-01 ~]# docker pull ubuntu:14.04
[root@hecs-hqs-01 ~]# docker pull ubuntu
2、显示本地镜像列表
# 查看语法
[root@hqs ~]# docker images --help
Usage: docker images [OPTIONS选项] [REPOSITORY仓库[:TAG标签]] # 查看语法只能用镜像仓库或者镜像仓库+标签
List images
Options:
-a, --all Show all images (default hides intermediate images) # 列出本地所有的镜像（含中间镜像）
--digests Show digests # 显示镜像摘要值
-f, --filter filter Filter output based on conditions provided # 显示过滤的镜像
--format string Pretty-print images using a Go template
--no-trunc Dont truncate output # 不截断输出（显示完整的镜像id）
-q, --quiet Only show numeric IDs # 只显示镜像ID
# 查看本地镜像案例
[root@hqs docker-hello]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker-hello latest 7131e3b64d77 42 minutes ago 861kB
ubuntu latest 2b4cba85892a 5 days ago 72.8MB
[root@hqs docker-hello]# docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
docker-hello latest 7131e3b64d77 42 minutes ago 861kB
ubuntu latest 2b4cba85892a 5 days ago 72.8MB
# -f选项可以通过dangling的布尔值列出无标签的镜像（?没有输出）
# -f 选项还可以匹配镜像名、镜像ID、镜像DIGEST标识符
[root@hqs /]# docker images -f dangling=true
REPOSITORY TAG IMAGE ID CREATED SIZE
# -f before=(<镜像名>[:标签]|<镜像ID>|<镜像digest>) 过滤出指定镜像之前创建的
# -f since=(<镜像名>[:标签]|<镜像ID>|<镜像digest>) 过滤出指定镜像之后创建的
# 使用镜像名加标签标识
[root@hqs docker-hello]# docker images -f before=ubuntu:latest
REPOSITORY TAG IMAGE ID CREATED SIZE
centos/httpd latest 2cc07fbb5000 3 years ago 258MB
centos/httpd version1.0 2cc07fbb5000 3 years ago 258MB
# 使用镜像ID标识
[root@hqs docker-hello]# docker images -f before=2b4cba85892a
REPOSITORY TAG IMAGE ID CREATED SIZE
centos/httpd latest 2cc07fbb5000 3 years ago 258MB
centos/httpd version1.0 2cc07fbb5000 3 years ago 258MB
# 使用digest值标识
[root@hqs docker-hello]# docker images -f since=golang@sha256:c72fa9afc50b3303e8044cf28fb358b48032a548e1825819420fd40155a131cb
REPOSITORY TAG IMAGE ID CREATED SIZE
docker-hello latest 709f66f2ceec 35 minutes ago 861kB
ubuntu latest 2b4cba85892a 6 days ago 72.8MB
# 通过shell命令替换docker images命令实现镜像的批量操作（重点）
[root@hqs /]# docker images -q
27f012ef630b
2b4cba85892a
5d0da3dc9764
13b66b487594
[root@hqs /]# docker rmi $(docker images centos -q)
Untagged: centos:latest
Untagged: centos@sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
Deleted: sha256:5d0da3dc976460b72c77d94c8a1ad043720b0416bfc16c52c45d4847e53fadb6
Deleted: sha256:74ddd0ec08fa43d09f32636ba91a0a3053b02cb4627c35051aff89f853606b59
3、设置镜像标签
标签：描述镜像的版本信息，可以使用docker tag为镜像添加标签，即为镜像命名。
镜像仓库可以有多个标签。一个镜像也可以有多个标签。
如果一个镜像有多个标签，只有当最后一个标签被删除时，才真正删除镜像。
# 基本语法
# 创建标签让目标镜像关联到源镜像
docker tag SOURCE_IMAGE[:TAG] TARGET_IMAGE[:TAG]
docker tag 源镜像[:标签] 目标镜像[:标签]
# 下载centos/httpd镜像
[root@hqs ~]# docker pull centos/httpd
Using default tag: latest
latest: Pulling from centos/httpd
a02a4930cb5d: Pull complete
628eaef4a9e0: Pull complete
20c0ca1c0cd5: Pull complete
30cf2fb1a57e: Pull complete
Digest: sha256:26c6674463ff3b8529874b17f8bb55d21a0dcf86e025eafb3c9eeee15ee4f369
Status: Downloaded newer image for centos/httpd:latest
docker.io/centos/httpd:latest
# 为由镜像ID标识的镜像加标签
[root@hqs ~]# docker tag 2cc07fbb5000 centos/httpd:version1.0
[root@hqs ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos/httpd latest 2cc07fbb5000 3 years ago 258MB
centos/httpd version1.0 2cc07fbb5000 3 years ago 258MB
# 为由仓库名称标识的镜像加上标签
[root@hqs docker-hello]# docker tag centos/httpd centos/httpd:version2.0
[root@hqs docker-hello]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos/httpd latest 2cc07fbb5000 3 years ago 258MB
centos/httpd version1.0 2cc07fbb5000 3 years ago 258MB
centos/httpd version2.0 2cc07fbb5000 3 years ago 258MB
# 为由仓库名称和镜像ID组合标识的镜像加上标签 存疑
[root@hqs ~]# docker tag centos/httpd:latest centos/httpd:version3.0.test
[root@hqs ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos/httpd latest 2cc07fbb5000 3 years ago 258MB
centos/httpd version1.0 2cc07fbb5000 3 years ago 258MB
centos/httpd version2.0 2cc07fbb5000 3 years ago 258MB
centos/httpd version3.0.test 2cc07fbb5000 3 years ago
[root@bruce my-hello]# docker tag hello-world:latest hqs/hello-world:version4.0.test
[root@bruce my-hello]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hqs/hello-world version4.0.test f21f18b39c4d 27 minutes ago 865kB
# 指定一个注册服务器的主机名（可能包含端口） 存疑
[root@hqs ~]# docker tag 2cc07fbb5000 aliyun:5000/centos/httpd:version4.0
[root@hqs ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
aliyun:5000/centos/httpd version4.0 2cc07fbb5000 3 years ago 258MB
[root@bruce my-hello]# docker tag f21f18b39c4d myhost:5000/hqs/hello-world:version5.0
[root@bruce my-hello]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
myhost:5000/hqs/hello-world version5.0 f21f18b39c4d 27 minutes ago 865kB
4、查看镜像详细信息
docker inspect 命令查看Docker对象（镜像、容器、任务）的详细信息。
- 默认以JSON数组格式输出结果。
- 可以使用
-f(--format)选项指定特定内容输出
# 语法
Usage: docker inspect [OPTIONS] NAME|ID [NAME|ID...]
Return low-level information on Docker objects 返回详细docker对象信息
Options:
-f, --format string Format the output using the given Go template # 格式化输出
-s, --size Display total file sizes if the type is container # 容器类型显示全部文件大小
--type string Return JSON for specified type # 返回json格式信息
[root@hqs ~]# docker inspect centos/httpd
[
{
"Id": "sha256:2cc07fbb5000234e85b7ef63b6253f397491959af2a24251b6ae20c207beb814",
...
"Metadata": {
"LastTagTime": "2022-03-10T02:35:56.032309948+08:00"
}
}
]
# 获取镜像的体系结构
[root@hqs ~]# docker inspect --format='{{.Architecture}}' centos/httpd
amd64
# 获取镜像的根文件系统信息
[root@hqs ~]# docker inspect --format='{{.RootFS}}' centos/httpd
{layers [sha256:071d8bd765171080d01682844524be57ac9883e53079b6ac66707e192ea25956 sha256:d15c61d3ecdaa582e75e2966792238c0325578ec9e0d2a1ed3183995345323d6 sha256:7c937d8a9f4f7a9761c292a6c7bcff1cc10384985282fa4fa5a04bfdb155bc90 sha256:920640105caf8a18f7db0df2638b863cbc73c2e0668d0559c5f9c93c474e8879] }
# 用json格式输出
[root@hqs ~]# docker inspect --format='{{json .RootFS}}' centos/httpd # 注意json后空格
{"Type":"layers","Layers":["sha256:071d8bd765171080d01682844524be57ac9883e53079b6ac66707e192ea25956","sha256:d15c61d3ecdaa582e75e2966792238c0325578ec9e0d2a1ed3183995345323d6","sha256:7c937d8a9f4f7a9761c292a6c7bcff1cc10384985282fa4fa5a04bfdb155bc90","sha256:920640105caf8a18f7db0df2638b863cbc73c2e0668d0559c5f9c93c474e8879"]}
# grep过滤没有-f好用
[root@hqs ~]# docker inspect golang | grep Architecture
"Architecture": "amd64",
[root@hqs ~]# docker inspect golang | grep RootFS
"RootFS": {
5、查看镜像的构建历史
可以使用 docker history 来查看镜像的构建历史，即 DockerFile的执行过程。
每一层镜像都相当于一个子镜像。
# 语法
Usage: docker history [OPTIONS] IMAGE
Show the history of an image
Options:
--format string Pretty-print images using a Go template
-H, --human Print sizes and dates in human readable format (default true)
--no-trunc Dont truncate output
-q, --quiet Only show numeric IDs
[root@hqs docker-hello]# docker history docker-hello
IMAGE CREATED CREATED BY (构建操作命令) SIZE COMMENT
709f66f2ceec 3 minutes ago /bin/sh -c #(nop) CMD ["/hello"] 0B
e5dd9d7e1e8f 3 minutes ago /bin/sh -c #(nop) COPY file:437c07ddb3f63bb1… 861kB
[root@hqs docker-hello]# docker history ubuntu
IMAGE CREATED CREATED BY SIZE COMMENT
2b4cba85892a 5 days ago /bin/sh -c #(nop) CMD ["bash"] 0B
<missing> 5 days ago /bin/sh -c #(nop) ADD file:8a50ad78a668527e9… 72.8MB
[root@hqs docker-hello]# docker history ubuntu:14.04
IMAGE CREATED CREATED BY SIZE COMMENT
13b66b487594 11 months ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B
<missing> 11 months ago /bin/sh -c mkdir -p /run/systemd && echo do… 7B
<missing> 11 months ago /bin/sh -c [ -z "$(apt-get indextargets)" ] 0B
<missing> 11 months ago /bin/sh -c set -xe && echo '#!/bin/sh' > /… 195kB
<missing> 11 months ago /bin/sh -c #(nop) ADD file:276b5d943a4d284f8… 196MB
# format格式化输出案例
[root@localhost ~]# docker image history --format {{.CreatedBy}} ubuntu:14.04
/bin/sh -c #(nop) CMD ["/bin/bash"]
/bin/sh -c mkdir -p /run/systemd && echo 'do…
/bin/sh -c [ -z "$(apt-get indextargets)" ]
/bin/sh -c set -xe && echo '#!/bin/sh' > /…
/bin/sh -c #(nop) ADD file:276b5d943a4d284f8…
# -q只显示id
[root@localhost ~]# docker image history -q ubuntu:14.04
13b66b487594
<missing>
<missing>
<missing>
<missing>
输出结果中 CREATED BY 列显示的是每一层的构建操作命令。如果显示不全，可以使用 --no-trunc 选项来显示完整的操作命令。
[root@hqs docker-hello]# docker history ubuntu:14.04 --no-trunc
另外，执行该命令时，有时会输出 <missing> 行，这表明响应的层在其他系统已经构建了，并且已经不可用吗，可以忽略。
6、查找镜像
在命令行中可以使用 docker search 命令搜索docker hub中的镜像。
# 语法
Usage: docker search [OPTIONS] TERM
Search the Docker Hub for images
Options:
-f, --filter filter Filter output based on conditions provided
--format string Pretty-print search using a Go template
--limit int Max number of search results (default 25)
--no-trunc Dont truncate output
# 示例
[root@hqs docker-hello]# docker search mysql
镜像仓库（源）名称 描述 星数（点赞收藏） 是否官方发布 自动化
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
mysql MySQL is a widely used, open-source relation… 12227 [OK]
mariadb MariaDB Server is a high performing open sou… 4693 [OK]
mysql/mysql-server Optimized MySQL Server Docker images. Create… 907 [OK]
# limit限制数量
[root@bruce ~]# docker search --limit 5 ubuntu
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
ubuntu Ubuntu is a Debian-based Linux operating sys… 15650 [OK]
websphere-liberty WebSphere Liberty multi-architecture images … 292 [OK]
open-liberty Open Liberty multi-architecture images based… 58 [OK]
neurodebian NeuroDebian provides neuroscience research s… 98 [OK]
ubuntu-debootstrap DEPRECATED; use "ubuntu" instead 50 [OK]
# no-trunc不截断显示
[root@bruce ~]# docker search --limit 2 --no-trunc ubuntu
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
ubuntu Ubuntu is a Debian-based Linux operating system based on free software. 15650 [OK]
websphere-liberty WebSphere Liberty multi-architecture images based on Ubuntu 18.04 292 [OK]
# filter筛选输出
# 只搜索官方镜像
[root@bruce ~]# docker search --filter "is-official=true" ubuntu
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
ubuntu Ubuntu is a Debian-based Linux operating sys… 15650 [OK]
websphere-liberty WebSphere Liberty multi-architecture images … 292 [OK]
# 搜索指定大于多少星的镜像
[root@bruce ~]# docker search --filter stars=10000 ubuntu
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
ubuntu Ubuntu is a Debian-based Linux operating sys… 15650 [OK]
# format格式化输出
# 镜像名：.Name
# 镜像描述：.Description
# star数量：.StarCount
# 官方镜像：.IsOfficial
# 自动构建：.IsAutomated
[root@bruce ~]# docker search --format '{{.Name}}' ubuntu
ubuntu
websphere-liberty
open-liberty
neurodebian
[root@bruce ~]# docker search --format '{{.Name}}-{{.StarCount}}' ubuntu
ubuntu-15650
websphere-liberty-292
open-liberty-58
[root@bruce ~]# docker search --format 'table {{.Name}}\t{{.StarCount}}\t{{.IsAutomated}}\t{{.IsOfficial}}' ubuntu
NAME STARS AUTOMATED OFFICIAL
ubuntu 15650 [OK]
websphere-liberty 292 [OK]
open-liberty 58 [OK]
neurodebian 98 [OK]
ubuntu-debootstrap 50 [OK]
ubuntu-upstart 112 [OK]
7、删除本地镜像
使用镜像的ID、标签、镜像摘要标识符来指定删除本地镜像。
如果一个镜像有多个标签，则当最后一个标签被删除时，镜像才真正删除。
# docker子命令语法
Usage: docker rmi [OPTIONS] IMAGE [IMAGE...]
Remove one or more images
Options:
-f, --force Force removal of the image # 强制删除
--no-prune Do not delete untagged parents # 不删除没有标签的父镜像
# docker image 子命令语法
Usage: docker image rm [OPTIONS] IMAGE [IMAGE...]
Remove one or more images
Aliases: rm, rmi, remove
Options:
-f, --force Force removal of the image
--no-prune Do not delete untagged parents
# 镜像ID标识
[root@hqs docker-hello]# docker rmi 2cc07fbb5000
# 镜像标签标识
[root@hqs docker-hello]# docker rmi ubuntu:14.04
# 镜像摘要标识
[root@hqs docker-hello]# docker image rm ubuntu@sha256:8ae9bafbb64f63a50caab98fd3a5e37b3eb837a3e0780b78e5218e63193961f9
# 特别案例：镜像摘要标识，先删了摘要再删了镜像
[root@hqs ~]# docker images --digests
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZE
golang latest sha256:c72fa9afc50b3303e8044cf28fb358b48032a548e1825819420fd40155a131cb 276895edf967 2 months ago 941MB
centos latest sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177 5d0da3dc9764 5 months ago 231MB
[root@hqs ~]# docker image rm golang@sha256:c72fa9afc50b3303e8044cf28fb358b48032a548e1825819420fd40155a131cb
Untagged: golang@sha256:c72fa9afc50b3303e8044cf28fb358b48032a548e1825819420fd40155a131cb
[root@hqs ~]# docker images --digests -a
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZE
golang latest <none> 276895edf967 2 months ago 941MB
centos latest sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177 5d0da3dc9764 5 months ago 231MB
[root@hqs ~]# docker image rm golang:latest
Untagged: golang:latest
Deleted: sha256:276895edf9673267f47528e8a99401f2d2947f6c9c00490f773d5ed8f559bef2
Deleted: sha256:f9925574d34663c6f0f2135512cd1e7b94490279982657a6a40fb0693ce9df41
Deleted: sha256:5ba934ce54ed16893dd8cae2c36bdcc25f9cb1a4d51dba9cbedda4b4f1bbf53f
Deleted: sha256:3a9da346a75c7c4cdacacd945f87d73b964a07007c4e5e8f9435c367176ceeb9
Deleted: sha256:cbce712ed17923285239f9d9c0528984aef065b7413d68a0290e2c8eecc98f4a
Deleted: sha256:aa56d037ee5925ebf11127c3e1f617874c4ce8bae6b6af7d132b7f7a4a606e6f
Deleted: sha256:97e5f44efb543d466c5847602654a8cb22c9466b61d04988d47ec44b197ea874
Deleted: sha256:11936051f93baf5a4fb090a8fa0999309b8173556f7826598e235e8a82127bce
# 强制删除————容器还在，强制删除镜像
[root@bruce ~]# docker image rm --force ubuntu:latest
Untagged: ubuntu:latest
Untagged: ubuntu@sha256:626ffe58f6e7566e00254b638eb7e0f3b11d4da9675088f4781a50ae288f3322
Deleted: sha256:ba6acccedd2923aee4c2acc6a23780b14ed4b8a5fa4e14e252a23b846df9b6c1
[root@bruce ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu 14.04 13b66b487594 23 months ago 196MB
centos/httpd latest 2cc07fbb5000 4 years ago 258MB
[root@bruce ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
4357949b994d ba6acccedd29 "bash" About a minute ago Exited (0) About a minute ago xenodochial_wright
# no-prune不删除没有标签的父镜像————仅删除latest标签的镜像
[root@bruce ~]# docker pull hello-world
[root@bruce ~]# docker tag feb5d9fea6a5 hello-world:version1.0
[root@bruce ~]# docker image rm --no-prune hello-world
Untagged: hello-world:latest
[root@bruce ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world version1.0 feb5d9fea6a5 17 months ago 13.3kB
ubuntu 14.04 13b66b487594 23 months ago 196MB
centos/httpd latest 2cc07fbb5000 4 years ago 258MB
[root@bruce ~]# docker image rm --no-prune ubuntu
Error response from daemon: No such image: ubuntu:latest
8、验证镜像分层结构（构建镜像）
验证基于 Dockerfile 文件的镜像分层。
# 1、构建项目目录，存放Dockerfile和相关文件
[root@hqs ~]# mkdir /home/hqs/imglayers && cd /home/hqs/imglayers
# 2、建立app子目录和py文件
[root@hqs imglayers]# mkdir app && cd app
[root@hqs app]# vi app.py
#!/usr/bin/python
print("Hello, World!@!!!!!!")
# 3、编辑Dockerfile文件
[root@hqs app]# cd ..
[root@hqs imglayers]# vi Dockerfile
FROM ubuntu:16.04
COPY ./app /app
RUN apt-get -y update && apt-get install -y python
CMD python /app/app.py
# 4、构建镜像
[root@hqs imglayers]# docker build -t="imglayers-test" .
# 5、查看镜像的分层信息
[root@hqs imglayers]# docker history imglayers-test
IMAGE CREATED CREATED BY SIZE COMMENT
9ef4ec73ba1e 8 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "pyth… 0B
aaec11036262 8 minutes ago /bin/sh -c apt-get -y update && apt-get inst… 64.1MB
c53a6ee7c2be 11 minutes ago /bin/sh -c #(nop) COPY dir:c47add2988178f681… 48B
b6f507652425 6 months ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B
<missing> 6 months ago /bin/sh -c mkdir -p /run/systemd && echo 'do… 7B
<missing> 6 months ago /bin/sh -c rm -rf /var/lib/apt/lists/* 0B
<missing> 6 months ago /bin/sh -c set -xe && echo '#!/bin/sh' > /… 745B
<missing> 6 months ago /bin/sh -c #(nop) ADD file:11b425d4c08e81a3e… 135MB
# 6、运行镜像
[root@hqs imglayers]# docker run imglayers-test
Hello, World!@!!!!!!
9、导出镜像
使用docker save 将指定镜像保存成 tar 归档文件。
将一个或多个镜像保存到归档文件中。
# 语法
[root@localhost ~]# docker save --help
Usage: docker save [OPTIONS] IMAGE [IMAGE...]
Save one or more images to a tar archive (streamed to STDOUT by default)
Options:
-o, --output string Write to a file, instead of STDOUT # 输出到指定文件
# 案例
[root@localhost ~]# docker save -o ubuntu-test.tar ubuntu:latest
[root@localhost ~]# du -sh ubuntu-test.tar
72M ubuntu-test.tar
10、装载镜像
使用docker load 从归档文件或标准输入装载镜像。
# 语法
[root@localhost ~]# docker load --help
Usage: docker load [OPTIONS]
Load an image from a tar archive or STDIN
Options:
-i, --input string Read from tar archive file, instead of STDIN # 读取指定归档文件
-q, --quiet Suppress the load output # 禁止读入输出
# 案例
[root@localhost ~]# docker load -i registry_latest.tar
d9ff549177a9: Loading layer 4.671MB/4.671MB
f641ef7a37ad: Loading layer 1.587MB/1.587MB
d5974ddb5a45: Loading layer 20.08MB/20.08MB
5bbc5831d696: Loading layer 3.584kB/3.584kB
73d61bf022fd: Loading layer 2.048kB/2.048kB
Loaded image: registry:latest
[root@localhost ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
registry latest f32a97de94e1 3 years ago 25.8MB
