Add fetch setup documentation

[708yamaguchi]

Duplicate of knorth55#107
This is fetch setup documentation of udev(#1309), supervisor(#1323), cron(#1332) and tmuxinator(#1337).

@tkmtnt7000

If you find fetch system which you do not know, please tell me or update this README.md

[k-okada]

@708yamaguchi what is the philosophy behind mixing tmux/supervisor/upstart?
@sktometometo how about spot setting? do you use these three system? Or did you choose one of them?

[sktometometo]

@k-okada We don't use this system for spot currently. Auto-start and job management systems are not deployed for Spot. But if we want to do that, I will transplant fetch system to spot.

[sktometometo]

As far as I know, upstart scripts are not used now. All of them are reimplemented by supervisor because service management can be done by web browser if we use supervisor.

[sktometometo]

And tmuxinator is used as shortcut command of log browsing of multiple services at the same time. With that, developers can see service logs of multiple services without manually open multiple tmux sesstions and log files.

[708yamaguchi]

@sktometometo

thank you for your explanation.

I'm updating README.
I will update this PR soon.

[k-okada]

please consider building robot-agnostic auto-start roscore/roslaunch system when you copy scripts from fetch to spot. #1323 (comment)

As for browsing logs, I thinksupervisord have it's own way of doing that. Using supervisorctl????

k-okada@p51s:/etc/supervisor/conf.d$ sudo supervisorctl -i 
echo                             RUNNING   pid 9986, uptime 0:00:08
supervisor> pid all
9986
supervisor> status
echo                             RUNNING   pid 9986, uptime 0:00:35
supervisor> fg echo
JST 2021
Tue Sep 21 18:09:09 JST 2021
Tue Sep 21 18:09:10 JST 2021
Tue Sep 21 18:09:11 JST 2021
Tue Sep 21 18:09:12 JST 2021

[708yamaguchi]

please consider building robot-agnostic auto-start roscore/roslaunch system when you copy scripts from fetch to spot. #1323 (comment)

OK.
I think some of supervisor jobs can be moved to jsk_robot_startup.

As for browsing logs, I thinksupervisord have it's own way of doing that. Using supervisorctl????

I find documentation.

supervisord: server piece (e.g. launch job)
supervisorctl: client piece (e.g. view job log)

The server piece of supervisor is named supervisord.

The command-line client piece of the supervisor is named supervisorctl. It provides a shell-like interface to the features provided by supervisord. From supervisorctl, a user can connect to different supervisord processes (one at a time), get status on the subprocesses controlled by, stop and start subprocesses of, and get lists of running processes of a supervisord.

http://supervisord.org/introduction.html#supervisor-components

[k-okada]

As far as I know, upstart scripts are not used now.

@sktometometo so can we close #1208 ???

[sktometometo]

@k-okada that PR includes scripts not related with upstart.

[sktometometo]

@708yamaguchi there is a conflict. please resolve it.

[708yamaguchi]

@sktometometo

Thank you. I updated.