Docker export import containers, save load images, commit containers, docker images tree

本文讨论一下与docker镜像相关的几个接口.

制作镜像相关 : 

使用dockerfile制作一个sshd镜像

http://blog.163.com/digoal@126/blog/static/1638770402014102711413675/

从container制作镜像(使用docker commit)

http://blog.163.com/digoal@126/blog/static/1638770402014923112924656/

制作base镜像

http://blog.163.com/digoal@126/blog/static/163877040201410443845799/

另外Docker还可以导出container到一个文件(docker export)

将文件导入成为镜像(docker import).

同时还支持导出已有镜像到一个文件,(docker save)

将镜像导入(docker load).

使用举例 : 

save镜像, load to image : 

查看镜像
[root@db-172-16-3-221 ~]# docker images
REPOSITORY                   TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
registry                     0.8.1               3e7767ddd728        5 weeks ago         427.9 MB

导出到一个tar文件
[root@db-172-16-3-221 ~]# docker save -o ./registry.tar 3e7767ddd728
[root@db-172-16-3-221 ~]# ll -h registry.tar
-rw-r--r-- 1 root root 427M Dec  5 14:09 registry.tar

将tar文件拷贝到另一台主机
[root@db-172-16-3-221 ~]# scp registry.tar 172.16.3.150:/opt/soft_bak/

在另一台主机导入
[root@localhost soft_bak]# docker load -i /opt/soft_bak/registry.tar

导入后未命名
[root@localhost soft_bak]# docker images
<none>                                <none>              3e7767ddd728        5 weeks ago         427.9 MB

打上tag
[root@localhost soft_bak]# docker tag 3e7767ddd728 digoal/registry
[root@localhost soft_bak]# docker images
digoal/registry                       latest              3e7767ddd728        5 weeks ago         427.9 MB

参考以下方法使用刚才load进来的image创建一个私有registry.
http://blog.163.com/digoal@126/blog/static/163877040201410393931894/
[root@localhost registry_conf]# docker run -d --net="host" -p 5000:5000 -v /data01/registry_conf:/registory_conf -v /data01/registry_sto:/registry_sto -e DOCKER_REGISTRY_CONFIG=/registory_conf/config_sample.yml -e STORAGE_PATH=/registry_sto -e SETTINGS_FLAVOR=local --name=registry  digoal/registry
ea75c68e44b68d186b1551a6ddc8b70b1b0a39179ca28166eacd1be5751f7b27
[root@localhost registry_conf]#
[root@localhost registry_conf]# docker ps
CONTAINER ID        IMAGE                    COMMAND                CREATED             STATUS              PORTS               NAMES
ea75c68e44b6        digoal/registry:latest   "/bin/sh -c 'exec do   3 seconds ago       Up 2 seconds                            registry            

export container, import to image : 

查看当前正在运行或已经停止的container
[root@localhost registry_conf]# docker ps -a
CONTAINER ID        IMAGE                    COMMAND                CREATED             STATUS                    PORTS               NAMES
ea75c68e44b6        digoal/registry:latest   "/bin/sh -c 'exec do   4 minutes ago       Up 4 minutes                                  registry
4c098166cc5d        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       osd4
f6df72b9780f        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       osd3
02d922ce295b        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       osd2
59c41fc9560e        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       deploy
34a7ceefcfd3        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       osd1
9c9391eb3e1a        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       mon3
5de0fae0d8bd        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       mon2
fa24ec5115f6        digoal/sshd:latest       "/usr/sbin/sshd -D"    7 days ago          Exited (0) 28 hours ago                       mon1
使用docker export将container到处到tar文件
[root@localhost registry_conf]# docker export deploy > ./sshd.tar
[root@localhost registry_conf]# ll -h sshd.tar
-rw-r--r-- 1 root root 606M Dec  5 22:20 sshd.tar
使用docker import导入
[root@localhost registry_conf]# cat sshd.tar | docker import - digoal/sshd_deploy
9110f1eb1ce1e95285e9b0daa7451e7de5165e350df8289aa92a36cacf499bcc
查看导入的镜像
[root@localhost registry_conf]# docker images digoal/*
REPOSITORY           TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
digoal/sshd_deploy   latest              9110f1eb1ce1        19 seconds ago      620.4 MB
digoal/sshd          latest              3e5d8edfaeee        8 days ago          298.1 MB
digoal/registry      latest              3e7767ddd728        5 weeks ago         427.9 MB
使用导入的镜像, 创建一个容器
[root@localhost registry_conf]# docker run -t -i --rm digoal/sshd_deploy /bin/bash
容器中安装的软件仍在, 所以在容器中的改变都被打包到镜像了, 和docker commit制作的镜像类似.
[root@1a3adda5d7b9 /]# rpm -qa|grep deploy
ceph-deploy-1.5.20-0.noarch
ph-deploy
[root@1a3adda5d7b9 /]# cd /var/lib/ceph/
[root@1a3adda5d7b9 ceph]# ll
total 24
drwxr-xr-x 2 root root 4096 Oct 29 18:35 bootstrap-mds
drwxr-xr-x 2 root root 4096 Oct 29 18:35 bootstrap-osd
drwxr-xr-x 2 root root 4096 Oct 29 18:35 mds
drwxr-xr-x 2 root root 4096 Oct 29 18:35 mon
drwxr-xr-x 2 root root 4096 Oct 29 18:35 osd
drwxr-xr-x 2 root root 4096 Oct 29 18:35 tmp

最后docker镜像查看还支持tree输出. 可以列出镜像之间的关系.

例如digoal/postgresql:9.3.5是使用centos:centos6镜像制作的, 所以打印出了继承关系

还有很多未命名的, 是制作镜像时使用RUN产生的中间镜像.

[root@localhost registry_conf]# docker images -a --tree
Warning: '--tree' is deprecated, it will be removed soon. See usage.
  └─5b12ef8fd570 Virtual Size: 0 B
    ├─192178b11d36 Virtual Size: 466.9 MB Tags: centos:centos5
    ├─70441cac1ed5 Virtual Size: 215.8 MB Tags: centos:centos6
    │ └─d70b9ae9e9ff Virtual Size: 330.3 MB Tags: 172.16.3.221:5000/digoal/postgresql:9.3.5
    └─ae0c2d0bdc10 Virtual Size: 224 MB Tags: centos:centos7
      └─3c5e418bb4b1 Virtual Size: 224 MB
        └─c48a513d5431 Virtual Size: 298.1 MB
          └─e61b7a8bb4d9 Virtual Size: 298.1 MB
            └─8ed4d6eb45c1 Virtual Size: 298.1 MB
              └─ecb67638a0df Virtual Size: 298.1 MB
                └─2b73dfeaebf1 Virtual Size: 298.1 MB
                  └─6e0fcfed929b Virtual Size: 298.1 MB
                    └─3e5d8edfaeee Virtual Size: 298.1 MB Tags: digoal/sshd:latest

[参考]
1. http://tuhrig.de/difference-between-save-and-export-in-docker/

2. http://tuhrig.de/flatten-a-docker-container-or-image/

3. http://www.jamescoyle.net/how-to/1512-export-and-import-a-docker-image-between-nodes