Some scenarios in rex involve need to disconnect from network and continue some work offline. While we have support for `async`, it still marks the job as failed when the managed hosts goes offline.

With this feature, we should be able to take control over the job status from the remote host, so that the job is marked as running even when the host goes down temporary as part of execution of the job.

Example of such a template:

<pre><code>$CONTROL_SCRIPT manual-mode
cat <<HELP | $CONTROL_SCRIPT update >/dev/null 
The script has switched to manual-mode. It will be acting
as running after this script finishes.

The control script is available in \$CONTROL_SCRIPT
env varaible.

To send output data to the job, on can do something like this:

    echo Hello world | $CONTROL_SCRIPT update

To mark the script as finished, one can do

   $CONTROL_SCRIPT finish 0

there the second argument should be the exit code the 
script ended with.
HELP
</code></pre>

After running this, one should be able to go to the remote host, reboot it and the job should still be running until @$CONTROL_SCRIPT finish 0@ is finished. Additional output can be sent to the job with @echo Hello world | $CONTROL_SCRIPT update@

Additional note:

the satellite needs to be installed with @--foreman-proxy-plugin-remote-execution-ssh-async-ssh=true@ in order for this to work.