Docker - 手动迁移镜像

在没有Docker Registry时,可以通过docker save和docker load命令完成镜像迁移的过程，先将镜像保存为压缩包，然后在其他位置再加载压缩包。

将镜像保存为压缩包文件

[root@CentOS-7 ~]# docker images nginx
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
docker.io/nginx     latest              5766334bdaa0        2 weeks ago         182.5 MB
[root@CentOS-7 ~]# 
[root@CentOS-7 ~]# docker save  nginx | gzip > nginx-latest.tar.gz
[root@CentOS-7 ~]# 
[root@CentOS-7 ~]# ls -lh nginx-latest.tar.gz 
-rw-r--r-- 1 root root 69M Apr 24 17:28 nginx-latest.tar.gz
[root@CentOS-7 ~]#

加载镜像

# docker images nginx
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
# 
# docker load -i nginx-latest.tar.gz 
5d6cbe0dbcf9: Loading layer [==================================================>] 129.2 MB/129.2 MB
aca7b1f22e02: Loading layer [==================================================>] 9.216 kB/9.216 kB
31fc28b38091: Loading layer [==================================================>] 61.24 MB/61.24 MB
97b903fe0f6f: Loading layer [==================================================>] 3.584 kB/3.584 kB
Loaded image: docker.io/nginx:latest>                                           ]    512 B/3.584 kB
# 
# docker images nginx
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
docker.io/nginx     latest              5766334bdaa0        2 weeks ago         182.5 MB
# 

快捷命令

将镜像从一个主机迁移到另一个主机：
docker save | bzip2 | ssh @ "cat | docker load"

[root@CentOS-7 ~]# docker images
REPOSITORY              TAG                 IMAGE ID            CREATED             SIZE
docker.io/hello-world   latest              48b5124b2768        3 months ago        1.84 kB
[root@CentOS-7 ~]# 
[root@CentOS-7 ~]# docker save hello-world | bzip2 | ssh root@10.140.1.120 "cat | docker load"
root@10.140.1.120's password: 
Loaded image: docker.io/hello-world:latest
[root@CentOS-7 ~]# 

[root@TestNode ~]# ip addr show enp0s3
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:3c:d9:72 brd ff:ff:ff:ff:ff:ff
    inet 10.140.1.120/24 brd 10.140.1.255 scope global dynamic enp0s3
       valid_lft 84898sec preferred_lft 84898sec
    inet6 fe80::a00:27ff:fe3c:d972/64 scope link 
       valid_lft forever preferred_lft forever
[root@TestNode ~]# 
[root@TestNode ~]# docker images hello-world
REPOSITORY              TAG                 IMAGE ID            CREATED             SIZE
docker.io/hello-world   latest              48b5124b2768        3 months ago        1.84 kB
[root@TestNode ~]#