commit

• 用法

Usage: docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]
Create a new image from a container's changes
-a, --author=       Author (e.g., "John Hannibal Smith <hannibal@a-team.com>")
-c, --change=[]     Apply Dockerfile instruction to the created image
--help=false        Print usage
-m, --message=      Commit message
-p, --pause=true    Pause container during commit

• 例子

$ sudo docker ps
ID                  IMAGE               COMMAND             CREATED             STATUS              PORTS
c3f279d17e0a        ubuntu:12.04        /bin/bash           7 days ago          Up 25 hours
197387f1b436        ubuntu:12.04        /bin/bash           7 days ago          Up 25 hours
$ sudo docker commit c3f279d17e0a  SvenDowideit/testimage:version3
f5283438590d
$ sudo docker images | head
REPOSITORY                        TAG                 ID                  CREATED             VIRTUAL SIZE
SvenDowideit/testimage            version3            f5283438590d        16 seconds ago      335.7 M

提交一个重新配置过的容器到镜像

$ sudo docker ps
ID                  IMAGE               COMMAND             CREATED             STATUS              PORTS
c3f279d17e0a        ubuntu:12.04        /bin/bash           7 days ago          Up 25 hours
197387f1b436        ubuntu:12.04        /bin/bash           7 days ago          Up 25 hours
$ sudo docker inspect -f "{{ .Config.Env }}" c3f279d17e0a
[HOME=/ PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin]
$ sudo docker commit --change "ENV DEBUG true" c3f279d17e0a SvenDowideit/testimage:version3
f5283438590d
$ sudo docker inspect -f "{{ .Config.Env }}" f5283438590d
[HOME=/ PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin DEBUG=true]

• 总结

这个命令的用处在于把有修改的container提交成新的Image，然后导出此Imange分发给其他场景中调试使用。Docker官方的建议是，当你在调试完Image的问题后，应该写一个新的Dockerfile文件来维护此Image。commit命令仅是一个临时创建Imange的辅助命令。