Question

My python application consists of main program and several modules. Each module contains

import logging
log = logging.getLogger('myapp.mymodule')

on global level. Handlers and other stuff initialized in main program, and typically all messages forwarded to syslog.

Now I want to launch multiple instances of application (configuration file with instance name can be specified as command line parameter). The question is: how to pass instance name to each imported module? I want logger name to look like ‘myappinstance.mymodule’ or ‘myapp.instance.module’. And I do not want to mess with configuration file parsing in each module, because this will require hardcoded config path.

Answer 1

Well, describing the problem really helps in solving it 🙂 Just had an idea of using environment variables to pass parameters across all modules:

main.py:

import os
os.environ['instance'] = 'blah'
import a

a.py:

import os
import b
print 'a:', os.environ['instance']

b.py:

import os
print 'b:', os.environ['instance']

$ python main.py

b: blah
a: blah

Any other ideas or critics for this one?