How to kill process inside container? Docker top command

Question

I have simple example from official guide at docker website.

I run the following:

sudo docker run -d ubuntu:latest /bin/sh -c "while true; do echo hello world; sleep 1; done"
a66asdasdhqie123...

Then take some output from created container:

sudo docker logs a66
hello
hello
hello
...

Then I lookup the running processes of a container:

sudo docker top a66
UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
root                25055               15152               0                   20:07               ?                   00:00:00            /bin/sh -c while true; do echo hello world; sleep 1; done
root                25295               25055               0                   20:10               ?                   00:00:00            sleep 1

Next I try to kill the first process of container:

sudo docker exec a66 kill -9 25055

However after I make it nothing changes. Process still works and output "hello" every second. What do I wrong?

score 37 · Accepted Answer · answered Jan 03 '15 at 20:16

37

When I reproduce your situation I see different PIDs between docker top <container> and docker exec -it <container> ps -aux. When you do docker exec the command is executed inside the container => should use container's pid. Otherwise you could do the kill without docker straight from the host, in your case: sudo kill -9 25055.

answered Jan 03 '15 at 20:16

Mykola Gurov

8,517
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1

and normally you would kill the process with `docker kill ` of course. – Mykola Gurov Jan 03 '15 at 20:19
Why do the PIDS differ between top and ids inside containers? That is 'top' command shows PIDS at the host machine? (Sorry can't check the answer I'm on mobile phone for now) – Timur Fayzrakhmanov Jan 03 '15 at 23:00
2

yes, `docker top` shows PIDs of the host, apparently. – Mykola Gurov Jan 03 '15 at 23:14
You can get PID from container as: `docker inspect --format {{.State.Pid}} ` – Demiurg Nov 21 '17 at 05:35

Ganesh Kamath - 'Code Frenzy' · Answer 2 · 2015-01-03T17:35:33.303

2

check this:

ps | grep -i a66 | tr -s ' '|cut -f2 -d' '|
{
    while read line;
    do kill -9 $line;
    done
}

to understand this start from executing commands from left till end of each pipe (|)

Simpler option:

kill $(pidof a66)

edited Jan 03 '15 at 17:35

answered Jan 03 '15 at 17:20

Ganesh Kamath - 'Code Frenzy'

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what is the return status ? – Ganesh Kamath - 'Code Frenzy' Jan 03 '15 at 17:25
The question is why my way doesn't work and not how to do it differently. – Timur Fayzrakhmanov Jan 03 '15 at 17:25
Sorry, but I don't like the way you suggest - it's very long and overwhelmed. May be there is more simple option? – Timur Fayzrakhmanov Jan 03 '15 at 17:27
i have edited the answer (add sudo if required). Hope this helps. – Ganesh Kamath - 'Code Frenzy' Jan 03 '15 at 17:36
`kill $(pidof a66)`. Where need I run it? Inside container or outside? Because there no effect wherever I run it.. – Timur Fayzrakhmanov Jan 03 '15 at 17:55
2

this answer is plain wrong. Docker container ids are not printed by `ps`. – Mykola Gurov Jan 03 '15 at 20:20

score 0 · Answer 3 · answered Feb 22 '16 at 04:27

0

Took me a while to find the right answer, but you will have to manage this process from within the container. When you run docker top a66 from the host, the PIDs are from your host, although that's not quite the case if using Cygwin. Regardless, you will need to bash or what-have-you back into your container and use commands like ps aux and kill while in the container to find and manage the different PIDs for the same processes there.

answered Feb 22 '16 at 04:27

Spencer Williams

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10
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1

Because the way Docker works the PID is always the HOST ( it is not a full VM like VirtualBox ). The container just "think" it owns the process. If you want to kill just use the PID from the host. – Magno C Feb 24 '23 at 11:53

score 0 · Answer 4 · answered Mar 31 '17 at 20:43

i was looking for something like this, but i couldn't find and then i did this:

[root@notebook ~]# docker exec -it tadeu_debian ps aux | grep ping | awk '{ print $2 }' | xargs -I{} docker exec -i tadeu_debian kill -9

It was two "execs" from Docker e one xargs.

Well, i hope this helps someone!

score -1 · Answer 5 · answered Apr 26 '21 at 08:48

-1

when you build Docker, use this command :

RUN apt-get install lsof

then in py file you can use:

os.system("lsof /dev/nvidia* | awk '{print $2}' | xargs -I {} kill {}")

REMEMBER: this command kill all process on GPU

answered Apr 26 '21 at 08:48

Ali Ganjbakhsh

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7
13

How to kill process inside container? Docker top command

5 Answers5

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