Docke 1.12 基礎篇:48條命令(5)
阿新 • • 發佈：2018-12-26
本文針對Docker1.12的48條命令，列出了container相關的18條命令,上一篇文章我們學習了容器生狀態管理的幾條命令,這這一篇中我們來看一下剩下的9條命令都能做什麼。
container相關的命令
| 項番 | 命令 | 詳解 |
|---|---|---|
| No.1 | attach | Attach to a running container |
| No.9 | exec | Run a command in a running container |
| No.3 | commit | Create a new image from a container’s changes |
| No.4 | cp | Copy files/folders between a container and the local filesystem |
| No.7 | diff | Inspect changes on a container’s filesystem |
| No.10 | export | Export a container’s filesystem as a tar archive |
| No.13 | import | Import the contents from a tarball to create a filesystem image |
| No.29 | rename | Rename a container |
| No.31 | rm | Remove one or more containers |
事前準備
先啟動一個container準備用來霍霍。
[root@liumiaocn ~]# docker run --name=nginx -d -p80:80 nginx
46be04227f8ae236ec47acf0dcb20e65389cb88e6d724439d6305813ce6b7f4e
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND exec
通過exec可以連線到一個正在執行的container執行一條命令，比如
[root@liumiaocn ~]# docker exec nginx hostname
46be04227f8a
[root@liumiaocn ~]#在實際中下面的方法用的更多,類似於連線到一個container中，然後可以執行各種操作
[root@liumiaocn ~]# docker exec -it nginx /bin/bash
root@46be04227f8a:/# hostname
46be04227f8a
root@46be04227f8a:/# pwd
/
root@46be04227f8a:/# exit
exit
[root@liumiaocn ~]#退出後也不會有副作用
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
46be04227f8a nginx "nginx -g 'daemon off" 2 minutes ago Up About a minute 0.0.0.0:80->80/tcp, 443/tcp nginx
[root@liumiaocn ~]#attach
attach到一個正在執行的container上，可以看到現在container的狀況,按ctrl+C退出會伴隨著container的退出，
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
46be04227f8a nginx "nginx -g 'daemon off" 2 minutes ago Up 2 minutes 0.0.0.0:80->80/tcp, 443/tcp nginx
[root@liumiaocn ~]# docker attach nginx
^C[root@liumiaocn ~]#
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
46be04227f8a nginx "nginx -g 'daemon off" 3 minutes ago Exited (0) 7 seconds ago nginx
[root@liumiaocn ~]#cp
docker cp用於將本地檔案copy到某容器內
在host上建立一個helloworld.txt的檔案
[root@liumiaocn ~]# echo "Hello world" >/tmp/helloworld.txt啟動一個busybox的container，確認該container的/tmp下什麼也沒有
[root@liumiaocn ~]# docker run --name busybox -it busybox /bin/sh
/ # cd /tmp
/tmp # ls -l
total 0
/tmp #docker cp
[root@liumiaocn ~]# docker cp /tmp/helloworld.txt busybox:/tmp
[root@liumiaocn ~]#確認container中的結果
/tmp # ls -l /tmp
total 4
-rw-r--r-- 1 root root 12 Sep 24 06:41 helloworld.txt
/tmp # cat /tmp/helloworld.txt
Hello world
/tmp #[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
44f08d7f4732 busybox "/bin/sh" 6 minutes ago Up 6 minutes busybox
[root@liumiaocn ~]#diff
docker是分層的，由映象檔案建立成容器，比如我們在docker cp中建立的container（44f08d7f4732），它有什麼變化呢，至少我們把helloworld.txt給copy到該container
的/tmp下了，我們怎樣才能看到這個差別呢
[root@liumiaocn ~]# docker diff busybox
C /root
A /root/.ash_history
C /tmp
A /tmp/helloworld.txt
[root@liumiaocn ~]#commit
但是當我們在這個時候同時在一個新的終端啟動一個busybox的container的時候，這個新的container的/tmp下什麼也沒有.
[root@liumiaocn ~]# docker run -it busybox /bin/sh
/ # ls /tmp
/ # exit
[root@liumiaocn ~]#為了證明這不是幻覺，使用ps -a來看一下剛才這個container是的確存在過的，只是我們退出了而已
[root@liumiaocn ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
63d08b54575c busybox "/bin/sh" 20 seconds ago Exited (0) 14 seconds ago angry_northcutt
44f08d7f4732 busybox "/bin/sh" 10 minutes ago Up 10 minutes busybox
[root@liumiaocn ~]#使用commit就可以解決這個問題了，把當前的變更儲存到映象中，在/tmp下顯示一個檔案不是什麼好的例子，但是如果在一個Ubuntu的Base上
安裝完JDK做一次commit，在安裝完JDK之後的版本上再安裝Tomcat再做一次commit，是不是你就可以得到了三個版本的映象了，當然更多的做法是通過
dockerfile來實現的，但是commit倒也簡單有效。
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
44f08d7f4732 busybox "/bin/sh" 15 minutes ago Up 15 minutes busybox
[root@liumiaocn ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox latest 2b8fd9751c4c 3 months ago 1.093 MB
74th/redmine-all-in-one latest cbd38a5bb23d 7 months ago 1.515 GB
[root@liumiaocn ~]# docker commit 44f08d7f4732 busybox:v2
sha256:185ccb97f18acf478b9a3a63964fcab96d2f2cc753e6ec16341013bbc0daa342
[root@liumiaocn ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox v2 185ccb97f18a 20 seconds ago 1.093 MB
busybox latest 2b8fd9751c4c 3 months ago 1.093 MB
74th/redmine-all-in-one latest cbd38a5bb23d 7 months ago 1.515 GB
[root@liumiaocn ~]#使用這個新生成的映象busybox:v2啟動一下確認/tmp下確實存在剛才的變化內容。
[root@liumiaocn ~]# docker run -it busybox:v2 /bin/sh
/ # cd /tmp
/tmp # ls -l
total 4
-rw-r--r-- 1 root root 12 Sep 24 06:41 helloworld.txt
/tmp # cat helloworld.txt
Hello world
/tmp # exit
[root@liumiaocn ~]#使用commit生成的新的映象可以看出history的變化內容
[root@liumiaocn ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox v2 185ccb97f18a 13 minutes ago 1.093 MB
busybox latest 2b8fd9751c4c 3 months ago 1.093 MB
74th/redmine-all-in-one latest cbd38a5bb23d 7 months ago 1.515 GB
[root@liumiaocn ~]# docker history busybox:v2
IMAGE CREATED CREATED BY SIZE COMMENT
185ccb97f18a 13 minutes ago /bin/sh 73 B
2b8fd9751c4c 3 months ago /bin/sh -c #(nop) CMD ["sh"] 0 B
<missing> 3 months ago /bin/sh -c #(nop) ADD file:9ca60502d646bdd815 1.093 MB
[root@liumiaocn ~]#export
上面使用commit將正在執行的container做成了新的映象檔案，export則是可以用來將正在執行的container生成tar檔案
啟動一個container
[root@liumiaocn ~]# docker run -it busybox:v2 /bin/sh
/ #確認container然後將其export出來
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ea51341f60a5 busybox:v2 "/bin/sh" 19 seconds ago Up 18 seconds goofy_roentgen
[root@liumiaocn ~]# docker export ea51341f60a5 >busyboxv3.tar
[root@liumiaocn ~]# ll busyboxv3.tar
-rw-r--r--. 1 root root 1299968 Sep 24 15:18 busyboxv3.tar
[root@liumiaocn ~]#rename
用於將container的名稱進行修改
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ea51341f60a5 busybox:v2 "/bin/sh" About a minute ago Up About a minute goofy_roentgen
[root@liumiaocn ~]# docker rename goofy_roentgen busybox
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ea51341f60a5 busybox:v2 "/bin/sh" 2 minutes ago Up 2 minutes busybox
[root@liumiaocn ~]#rm
刪除container,如果刪除正在執行中的container，要麼stop之後再rm，要麼加上-f選項
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ea51341f60a5 busybox:v2 "/bin/sh" 3 minutes ago Up 3 minutes busybox
[root@liumiaocn ~]# docker rm -f busybox
busybox
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]#import
從tar檔案生成docker管理的映象檔案，與save/load的區別在於，這個會丟history的內容
[root@liumiaocn ~]# ll busyboxv3.tar
-rw-r--r--. 1 root root 1299968 Sep 24 15:18 busyboxv3.tar
[root@liumiaocn ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox v2 185ccb97f18a 25 minutes ago 1.093 MB
busybox latest 2b8fd9751c4c 3 months ago 1.093 MB
74th/redmine-all-in-one latest cbd38a5bb23d 7 months ago 1.515 GB
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]# docker import busyboxv3.tar busybox:v3
sha256:8227b6ef55ac3ffc6f4f2a0bf3ed31f96e32cd1275eeaa9f92cfd35eda9de0e1
[root@liumiaocn ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@liumiaocn ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
busybox v3 8227b6ef55ac 9 seconds ago 1.093 MB
busybox v2 185ccb97f18a 26 minutes ago 1.093 MB
busybox latest 2b8fd9751c4c 3 months ago 1.093 MB
74th/redmine-all-in-one latest cbd38a5bb23d 7 months ago 1.515 GB
[root@liumiaocn ~]# docker history busybox:v3
IMAGE CREATED CREATED BY SIZE COMMENT
8227b6ef55ac 19 seconds ago 1.093 MB Imported from -
[root@liumiaocn ~]#