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【docker】9. 镜像操作与实战

news 2025/7/9 18:02:30

镜像操作案例

查找镜像

docker search busybox

下载镜像

docker pull busybox:1.36.0

查看镜像及列表存储位置

root@LAPTOP-H2EI4I6A:~# docker images busybox
REPOSITORY   TAG       IMAGE ID       CREATED        SIZE
busybox      latest    517b897a6a83   2 months ago   4.27MB

在这里插入图片描述
查看 overlay2/repositories.json 文件，该文件记录已拉取镜像文件的信息

查看本地镜像，发现和 repositories.json 文件记录的信息相同

镜像过滤

￮根据仓库名列出镜像
列出特定的某个镜像，也就是说指定仓库名和标签

root@LAPTOP-H2EI4I6A:~# docker images nginx
REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
nginx        <none>    0f8498f13f3a   20 months ago   142MB
nginx        1.23.3    ac232364af84   20 months ago   142MB
root@LAPTOP-H2EI4I6A:~# docker images nginx:1.23.3
REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
nginx        1.23.3    ac232364af84   20 months ago   142MB

docker image ls 还支持强大的过滤器参数 --filter，或者简写 -f。
之前我们已经看到了使用过滤器来列出虚悬镜像的用法，它还有更多的用法。
查看某个位置之前的镜像 before,查看某个位置之后的镜像 since

root@LAPTOP-H2EI4I6A:~# docker images
REPOSITORY                                                               TAG       IMAGE ID       CREATED         SIZE
crpi-xp37q81m2et6ppvz.cn-hangzhou.personal.cr.aliyuncs.com/hacha/hacha   v0.1      517b897a6a83   2 months ago    4.27MB
busybox                                                                  latest    517b897a6a83   2 months ago    4.27MB
crpi-xp37q81m2et6ppvz.cn-hangzhou.personal.cr.aliyuncs.com/hacha/hacha   latest    d2c94e258dcb   19 months ago   13.3kB
nginx                                                                    <none>    0f8498f13f3a   20 months ago   142MB
nginx                                                                    1.23.3    ac232364af84   20 months ago   142MB
root@LAPTOP-H2EI4I6A:~# docker image ls -f since=crpi-xp37q81m2et6ppvz.cn-hangzhou.personal.cr.aliyuncs.com/hacha/hacha
REPOSITORY                                                               TAG       IMAGE ID       CREATED        SIZE
crpi-xp37q81m2et6ppvz.cn-hangzhou.personal.cr.aliyuncs.com/hacha/hacha   v0.1      517b897a6a83   2 months ago   4.27MB
busybox                                                                  latest    517b897a6a83   2 months ago   4.27MB
root@LAPTOP-H2EI4I6A:~# docker image ls -f before=crpi-xp37q81m2et6ppvz.cn-hangzhou.personal.cr.aliyuncs.com/hacha/hacha
REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
nginx        <none>    0f8498f13f3a   20 months ago   142MB
nginx        1.23.3    ac232364af84   20 months ago   142MB

查看镜像详情

root@LAPTOP-H2EI4I6A:~# docker inspect busybox:latest

在这里插入图片描述

查看镜像分层

Docker history 可以查看分层

root@LAPTOP-H2EI4I6A:~# docker history nginx:1.23.3
IMAGE          CREATED         CREATED BY                                      SIZE      COMMENT
ac232364af84   20 months ago   /bin/sh -c #(nop)  CMD ["nginx" "-g" "daemon…   0B        
<missing>      20 months ago   /bin/sh -c #(nop)  STOPSIGNAL SIGQUIT           0B        
<missing>      20 months ago   /bin/sh -c #(nop)  EXPOSE 80                    0B        
<missing>      20 months ago   /bin/sh -c #(nop)  ENTRYPOINT ["/docker-entr…   0B        
<missing>      20 months ago   /bin/sh -c #(nop) COPY file:e57eef017a414ca7…   4.62kB    
<missing>      20 months ago   /bin/sh -c #(nop) COPY file:abbcbf84dc17ee44…   1.27kB    
<missing>      20 months ago   /bin/sh -c #(nop) COPY file:5c18272734349488…   2.12kB    
<missing>      20 months ago   /bin/sh -c #(nop) COPY file:7b307b62e82255f0…   1.62kB    
<missing>      20 months ago   /bin/sh -c set -x     && addgroup --system -…   61.3MB    
<missing>      20 months ago   /bin/sh -c #(nop)  ENV PKG_RELEASE=1~bullseye   0B        
<missing>      20 months ago   /bin/sh -c #(nop)  ENV NJS_VERSION=0.7.9        0B        
<missing>      20 months ago   /bin/sh -c #(nop)  ENV NGINX_VERSION=1.23.3     0B        
<missing>      20 months ago   /bin/sh -c #(nop)  LABEL maintainer=NGINX Do…   0B        
<missing>      20 months ago   /bin/sh -c #(nop)  CMD ["bash"]                 0B        
<missing>      20 months ago   /bin/sh -c #(nop) ADD file:60911afdacfdc216e…   80.5MB

docker image inspect 可以查看详细的分层

一些镜像下载的时候也可以看到是一层一层下载的
在这里插入图片描述

打标签

docker tag busybox:1.36.0 ccr.ccs.tencentyun.com/maxhou6/busyboxbymaxhou:v3.0

推送镜像

docker pull ccr.ccs.tencentyun.com/maxhou6/busyboxbymaxhou:v3.0

运行容器

root@139-159-150-152:~# docker run -it --rm ccr.ccs.tencentyun.com/maxhou6/busyboxbymaxhou:v3.0 sh
/ # ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:11:00:08 inet addr:172.17.0.8 Bcast:172.17.255.255 
Mask:255.255.0.0UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX packets:7 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0 RX bytes:737 (737.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0UP LOOPBACK RUNNING MTU:65536 Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
/ # hostname
619291da55ec
/ # exit

镜像删除

镜像的删除：可以根据 id 和名字删除，对于使用的镜像需要先清理容器再删除镜像

root@139-159-150-152:~# docker rmi busybox:1.36.0
Untagged: busybox:1.36.0

镜像综合实战

实战一、离线迁移镜像

服务器 1 上镜像保存为 tar 文件，如操作系统为 ubuntu

root@139-159-150-152:/data/myworkdir# docker save -o busybox.tar busybox
root@139-159-150-152:/data/myworkdir# ll
total 147740
drwxr-xr-x 2 root root 4096 Mar 13 16:28 ./
drwx--x--x 5 root root 4096 Mar 13 15:03 ../
-rw------- 1 root root 5101568 Mar 13 16:28 busybox.tar
-rw------- 1 root root 146172416 Mar 13 15:05 mynginx_1.22.1.tar

scp 或者只用使用可视化工具拷贝镜像到第二台服务器上

root@139-159-150-152:/data/maxhou# scp busybox.tar root@43.138.218.166:/data/maxhou
The authenticity of host '43.138.218.166 (43.138.218.166)' can't 
be established.
ECDSA key fingerprint is 
SHA256:ai8KwGyM5W/iocUP8O00OMX7hriCD3ajd3wHVvdazTs.
Are you sure you want to continue connecting 
(yes/no/[fingerprint])? yes
Warning: Permanently added '43.138.218.166' (ECDSA) to the list of 
known hosts.
root@43.138.218.166's password: 
busybox.tar

第二台机器从 tar 中恢复镜像

[root@VM-8-12-centos maxhou]# docker load -i busybox.tar baacf561cfff: Loading layer 
[==================================================>] 
5.092MB/5.092MB
Loaded image: busybox:1.36.0

可以看到busybox镜像恢复出来了

[root@VM-8-12-centos maxhou]# docker images
REPOSITORY TAG IMAGE ID CREATED 
SIZE
busybox 1.36.0 7cfbbec8963d 3 weeks ago 
4.86MB
rabbitmq 3.9-management ef80153df89f 2 months ago 
269MB
ubuntu 1.0 955bd67a1123 3 months ago 
344MB
myubuntu 1.0 1de21ccbd1a1 3 months ago 
344MB
busybox latest 827365c7baf1 3 months ago 
4.86MB
redis 7.0 0256c63af7db 3 months ago

执行 docker run 检查镜像是否可以正常运行

[root@VM-8-12-centos maxhou]# docker run -it --rm busybox:1.36.0 sh 
/ # ls /
bin dev etc home lib lib64 proc root sys tmp 
usr var
/ # exit

实战二、镜像存储的压缩与共享

拉取 nginx 镜像，如果本地没有，镜像是从仓库拉取，如果有会提示镜像已经存在，并且是最新的。

root@139-159-150-152:~# docker pull nginx:1.21.1
1.21.1: Pulling from library/nginx
Digest: 
sha256:a05b0cdd4fc1be3b224ba9662ebdf98fe44c09c0c9215b45f84344c1286
7002e
Status: Image is up to date for nginx:1.21.1
docker.io/library/nginx:1.21.1

Docker images 查看本地镜像，可以看到该镜像为 142Mb
从上面看到 nginx 为 1.21.1 的大小是 140 多 MB,但是我们从 docker hub 上查看可
以看到镜像是 50 多 MB，说明发生了压缩，因为仓库到本地需要走网络，所以文件越
小越好
把一个镜像打多个 tag，然后同时推送仓库，可以看到是说层已经存在，不会重复存储

root@139-159-150-152:/data/maxhou# docker tag nginx:1.22.1 
maxhou/mybitnginx:1.22.1
root@139-159-150-152:/data/maxhou# docker tag nginx:1.22.1 
maxhou/mybitnginx:1.22.2
root@139-159-150-152:/data/maxhou# docker tag nginx:1.22.1 
maxhou/mybitnginx:1.22.3
root@139-159-150-152:/data/maxhou# docker tag nginx:1.22.1 
maxhou/mybitnginx:1.22.4
root@139-159-150-152:/data/maxhou# docker push maxhou/mybitnginx -a
The push refers to repository [docker.io/maxhou/mybitnginx]
9543dec06aa8: Layer already exists 
ccf4f419ba49: Layer already exists 
21f8452ebfb1: Layer already exists 
25bbf4633bb3: Layer already exists 
a4f34e6fb432: Layer already exists 
3af14c9a24c9: Layer already exists 
1.22.1: digest: 
sha256:9081064712674ffcff7b7bdf874c75bcb8e5fb933b65527026090dacda3
6ea8b size: 1570
9543dec06aa8: Layer already exists 
ccf4f419ba49: Layer already exists 
21f8452ebfb1: Layer already exists 
25bbf4633bb3: Layer already exists 
a4f34e6fb432: Layer already exists 
3af14c9a24c9: Layer already exists 
1.22.2: digest: 
sha256:9081064712674ffcff7b7bdf874c75bcb8e5fb933b65527026090dacda3
6ea8b size: 1570
9543dec06aa8: Layer already exists 
ccf4f419ba49: Layer already exists 
21f8452ebfb1: Layer already exists 
25bbf4633bb3: Layer already exists 
a4f34e6fb432: Layer already exists 
3af14c9a24c9: Layer already exists

添加一个新的镜像到我们的仓库的时候，如果 docker hub 发现已经有了是 mount的，不是从本地推上去的就会直接挂载

root@139-159-150-152:/data/maxhou# docker tag nginx:1.16.1 
maxhou/mybitnginx:1.16.1
root@139-159-150-152:/data/maxhou# docker push 
maxhou/mybitnginx:1.16.1
The push refers to repository [docker.io/maxhou/mybitnginx]
c23548ea0b99: Mounted from library/nginx 
82068c842707: Mounted from library/nginx 
c2adabaecedb: Mounted from library/nginx 
1.16.1: digest: 
sha256:2963fc49cc50883ba9af25f977a9997ff9af06b45c12d968b7985dc1e92
54e4b size: 948

你尝试将标记后的镜像推送到私有仓库（在这个例子中是docker.io/maxhou/mybitnginx）时，Docker Hub 会检查这个镜像的各个层。
如果发现这些层和公共仓库（library/nginx）中的镜像层是相同的，就会直接挂载（引用）这些已经存在于公共仓库的层，而不是再次传输相同的数据来重新构建这些层。这样可以显著提高效率，避免重复的网络传输和存储开销。