# pause: how to debug your Kubernetes setup

- Link: https://www.agilicus.com/pause-how-to-debug-your-kubernetes-setup/
- Published: 2019-03-28T19:45:14+00:00
- Author: Don Bowman

Sometimes you need a _debug_ container hanging around to check something from within
your cluster. You cobble something together, make the ‘command’ be ‘sleep 3600’ 
or ‘tail -f /dev/null’ and call it a day. But they don’t terminate gracefully.

    ```wp-block-code
    kubectl run debug --restart=Never --image=agilicus/pause
    ```

The magic is this ‘pause.c’. It simply waits for a couple of signals, calls pause(
2) and thus waits. It exits immediately if anything happens. This means that it 
uses near zero resources while sleeping and exits gracefully.

    ```wp-block-code
    #include <unistd.h>
    #include <signal.h>

    static void 
    _endme(int sig)
    {
      _exit(0);
    }
    int
    main(int argc, char **argv)
    {
      signal(SIGINT, _endme);
      signal(SIGTERM, _endme);
      pause();
      _exit(0);
    }
    ```

Now, this seems esoteric, but give it a try. Now, once you have run that `run` command
above, you can simply  `kubectl exec -it debug bash` and from in there `apk add 
tool`.

So you might `apk add curl` and then `curl http://myservice`. Simple, right?

Now, I know a lot of you are committing the cardinal sin of having a shell and debug
environment in every container `just in case`. Well, let me tell you, that security
attacker is going to love your `just in case` toolset. Why not let the container
run as root with a writeable filesystem and a compiler while we are at it.

You can check out the copious code @ [https://github.com/Agilicus/pause](https://github.com/Agilicus/pause).