docker 容器生命周期

参考博客:https://medium.com/devopsion/life-and-death-of-a-container-146dfc62f808

下面看一个比较有迷惑性的例子：

一、image test封装的python脚本如下：

1 import time
2 
3 i = 0
4 while True:
5     print(i)
6     i = i + 1
7     time.sleep(1)

二、build image 并且 run container，ctrl+c打断container

[yongqiang@yongqiang-pc test]$ sudo docker run --name test test
^C0
1
2
Traceback (most recent call last):
  File "./app.py", line 7, in <module>
    time.sleep(1)
KeyboardInterrupt

三、start重启container。注意，这次是start -a，在log中将可以看到两次的输出

[yongqiang@yongqiang-pc test]$ sudo docker start -a test
^C0
1
2
3
Traceback (most recent call last):
  File "./app.py", line 7, in <module>
    time.sleep(1)
KeyboardInterrupt
[yongqiang@yongqiang-pc test]$ sudo docker logs test
0
1
2
Traceback (most recent call last):
  File "./app.py", line 7, in <module>
    time.sleep(1)
KeyboardInterrupt
0
1
2
3
Traceback (most recent call last):
  File "./app.py", line 7, in <module>
    time.sleep(1)
KeyboardInterrupt

四、这次只是单纯的重启container，没有-a。log中将看不到这次的输出，但容器确实重启了。

[yongqiang@yongqiang-pc test]$ sudo docker start test
test
[yongqiang@yongqiang-pc test]$ sudo docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
b7a7235e2b80        test                "python ./app.py"   20 minutes ago      Up 8 seconds        8000/tcp            test
[yongqiang@yongqiang-pc test]$ sudo docker stop test
test
[yongqiang@yongqiang-pc test]$ sudo docker ps -a
CONTAINER ID        IMAGE                 COMMAND                  CREATED             STATUS                       PORTS               NAMES
b7a7235e2b80        test                  "python ./app.py"        20 minutes ago      Exited (137) 5 seconds ago                       test
[yongqiang@yongqiang-pc test]$ sudo docker logs test
0
1
2
Traceback (most recent call last):
  File "./app.py", line 7, in <module>
    time.sleep(1)
KeyboardInterrupt
0
1
2
3
Traceback (most recent call last):
  File "./app.py", line 7, in <module>
    time.sleep(1)
KeyboardInterrupt