Ubuntu – Run Python Server at Startup

bashpythonstartupUbuntu

I've got a few Python based servers that I need to run, and would like them to start automatically when I start my Ubuntu Server box. What is the best way to execute them like this?

I was hoping I could write a Bash script and use Screen to get them running in the background, where I can check on them every now and then, but where as

echo screen -d -m python

works just fine,

echo screen -d -m `sudo python /home/matt/tornadoServer/tornadoDeploy.py`

doesn't, with no error messages. Is that something to do with the spaces? Even though I did surround it with backquotes? I also tried:

WEB="screen -d -m `sudo python /home/matt/tornadoServer/tornadoDeploy.py`"
echo $WEB

As a way of escaping the spaces, but no luck. What's Bash scripting way to do this?

And, once the Bash script works, where can I put it to make it execute on startup?

Best Answer

Its failing because sudo is prompting for a password. Since there's no TTY open, its just waiting for you to enter one--or may, in fact, be instantly failing. If you're running this as root, you don't need to launch it as sudo.

However, what you likely want to do is alter tornadoDeploy.py to daemonize itself--that is, to detach itself, so that its not running with an open session. The python-daemonize library provides easy tools to allow you to do this. This eliminates having to deal with screen, while still allowing you to daemonize the process.

Related Solutions

Ubuntu execute python script at logon as root after user logon

rc.local is run at system boot, so well before a user logs on.

You have two options for running the script. One is to use visudo(8) to set up the command to allow to be run, with a NOPASSWD: tag in the command entry, and then just use sudo to start the command, perhaps from /etc/profile and whatever other files are needed for whichever shells people might use. It might be as simple as dropping something in /etc/profile.d/ if that exists. Eg, if everyone who logs in will be in group video then when you run visudo you'd want a rule like:

%video  ALL=NOPASSWD: /path/to/Linux_Asus_AI_remote.py

and then you'd invoke with:

sudo /path/to/Linux_Asus_AI_remote.py

The other option is to use pam_exec to run a command after login while still root; it's cleaner but more dangerous because if you make mistakes you can hose your system and be unable to login. If you want to examine this, read up on the PAM modules and how authentication and authorisation work and look in /etc/pam.d/; also, think carefully about how you'll restrict this to only happen for appropriate users.

Whichever method you choose, you'll probably want to make sure that this does not happen if logging in as root, to reduce the gunk that's involved in letting the admin user get into the system.

Ubuntu 9.10: how to troubleshoot a startup script that doesn’t appear to run

At the beginning of your script, add this line:

exec > /tmp/debug-my-script.txt 2>&1

Reboot. Now look at that file in /tmp - it should tell you what's going on.

By the way, in init.d scripts I tend to use commands with full path (/sbin/modprobe). I've been burned so many times by the restricted PATH used by those scripts, I make no assumptions now. :)

By the way, good Bash programming links:

http://mywiki.wooledge.org/BashFAQ

http://mywiki.wooledge.org/BashPitfalls

http://mywiki.wooledge.org/BashGuide

Best Answer

Related Solutions

Ubuntu execute python script at logon as root after user logon

Ubuntu 9.10: how to troubleshoot a startup script that doesn’t appear to run

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