python - Organizing pyramid / paster config files in a modular way -

i have pyramid application using paster ini file, hosted via uwsgi. want host different instances (i.e. development, staging, production), ideally without having touch config file @ all. different instances need different settings. approach like:

[app:base] sqlalchemy.url = some/connection/string/%(instance)s  [app:development] instance = development  [app:production] instance = production 

that not work, because instance not yet defined, when sqlalchemy.url defined. tried inject instance somehow outside, without success. i'm not able access environment variables. tried pass values via uwsgi_param nginx, not work.

how organize paster ini files in modular way, not have duplicate settings?

you can use "config:" url include settings file.

in "shared.ini"

[app:myapp] use = egg:myapp 

in "development.ini"

[app:main] use = config:shared.ini#myapp = 2 

in "production.ini"

[app:main] use = config:shared.ini#myapp = 3 

here's real world code uses pattern:

https://github.com/pylons/sdidev/blob/master/etc/development.ini