Please open a ticket about this. cron was not designed to do this but there is no reason it cannot do it.
On Tuesday, 22 May 2012 22:33:57 UTC-5, Michael Toomim wrote: > > I'm finding multiple problems getting cron to start the scheduler. Here's > the cron line: > @reboot dummyuser python web2py.py -K utility > ...but it does not work without modifying web2py source. > > First, let's get an easy bug out of the way. The web2py book gives this > example for @reboot: > > @reboot * * * * root *mycontroller/myfunction > > But those asterisks shouldn't be there for @reboot tasks. Can we remove > them from the book? > > Now, when I put that line into my crontab and run web2py, it gives me this > error: > > web2py Web Framework > Created by Massimo Di Pierro, Copyright 2007-2011 > Version 1.99.7 (2012-03-04 22:12:08) stable > Database drivers available: SQLite3, pymysql, psycopg2, pg8000, CouchDB, > IMAP > Starting hardcron... > please visit: > http://192.168.56.101:8000 > use "kill -SIGTERM 10818" to shutdown the web2py server > Exception in thread Thread-2: > Traceback (most recent call last): > File "/usr/lib/python2.6/threading.py", line 532, in __bootstrap_inner > self.run() > File "/home/toomim/projects/utility/web2py/gluon/newcron.py", line 234, > in run > shell=self.shell) > File "/usr/lib/python2.6/subprocess.py", line 633, in __init__ > errread, errwrite) > File "/usr/lib/python2.6/subprocess.py", line 1139, in _execute_child > raise child_exception > OSError: [Errno 2] No such file or directory > > This is an error in subprocess.Popen. I inserted some print statements and > found that it's calling it like this: > subprocess.Popen('python web2py.py -K utility') > > This is incorrect, it should be: > subprocess.Popen(['python', 'web2py.py' '-K' 'utility']) > > I was able to make it work by adding a call to split(), as you can see > here (in newcron.py: cronlauncher.run()): > def run(self): > import subprocess > proc = subprocess.Popen(self.cmd.split(), > > But I do not understand how anybody could have made this work before, > without adding a split() call? And what confuses me further is that there > is an explicit join() call in the __init__() method that runs immediately > beforehand, as if we really did NOT want to have lists: > > elif isinstance(cmd,list): > cmd = ' '.join(cmd) > > So does cron @reboot work for anybody running a script? It seems > impossible for it to work right now. Is this a bug? > > Finally, it would be great if we did not have to pass in a dummy user to > each cron line that does nothing... >
