How to debug an upstart script that breaks with an error?

Question

I have a process that I want to start as soon as my system rebooted any way, so I used an upstart script for this, but sometimes what I notice is that my process does not start during a hard reboot (shutdown and starting the machine), so I think that my upstart script will not load after a hard reboot. I believe that for Hard Reboot there is no runlevel.

I am confused that sometimes during reboot it works, but sometimes it does not work. And how can I debug this?

Below is my upstart script:

 # sudo start helper # sudo stop helper # sudo status helper start on runlevel [2345] stop on runlevel [!2345] chdir /data respawn pre-start script echo "[`date`] Agent Starting" >> /data/agent.log sleep 30 end script post-stop script echo "[`date`] Agent Stopping" >> /data/agent.log sleep 30 end script limit core unlimited unlimited limit nofile 100000 100000 setuid goldy exec python helper.py 

Is there any way to debug this from what is happening? I can easily reproduce this, I believe. Any pointers to what I can do here?

Note:

During the reboot, sometimes I see the log that I have in the pre-start script, but sometimes I do not see logging at all after the reboot, which means that my script upstart did not start. Is there something I need to change at runlevel to make it work?

I have a virtual machine that runs in Hypervisor and I work with Ubuntu.

Answer 1

Your process works well, BUT during system startup many things go in parallel.

IF mount (which makes the /data folder available) works later than your pre-start script , you won’t see the “results” of the pre-start script .

I suggest moving sleep 30 earlier (BTW 30 seconds seems too slow):

 pre-start script sleep 30 # sleep 10 should be enough echo "[`date`] Agent Starting" >> /data/agent.log end script