Docker container dies immediately after start? Then take a peek at this blog.

Here at Bobcares, we often receive requests to fix Docker related issues as part of our Server Management Services for cPanel users, web hosts, and online service providers.

Today we’ll take a look at the top causes for this issue and how to fix them.

Why Docker container dies immediately after the start

Normally, a docker container will automatically exit once its main process finishes.

In order to run the processes, you need to either leave something running in the foreground. Or else using any process manager such as runit or supervisord will also make the processes run.

In general, docker requires command(s) to keep running in the foreground. Otherwise, it will think that the application is stopped and it should shut down the container.

Solution for Docker container that dies immediately after the start

Recently, one of our customers approached us with this issue. And here is the start.sh file that he provided.

Now let’s see how our Support Engineers fix this issue for our customers.

We initially, start up the processes and services running in the background and use the below command at the end of the script.

wait [n ...]

In bash, this wait command will force the current process to wait for each specified process and then return its termination status. In case, if n is not given, all currently active child processes will be waited for, and the return status will be zero.

Now finally, the start.sh file would look as below.

Another simple solution can be by adding the below code at the end of the script.

while true; do sleep 1000; done

Or else you can also add this below code at the end of the script.

exec “$@”

[Need any assistance to fix Docker errors? – We’ll help you]

Conclusion

In short, the docker container will always exit after the main process completion. In order to keep it running, we need to leave something in the foreground or else we can also use any process manager. Today, we saw how our Engineers resolved this problem.