A buildout extension that enables substitution of assignments for extends option.
Normally buildout doesn't seem to take command-line assignment options into account when working with the buildout:extends option. buildout.extendssubs provides an option extends-subs that works exactly the same as extends option and also can substitute assignment variables. extends-subs can work together with extends option, in this case config files in extends option will be loaded first.
Check out source code from github.
$ git clone https://github.com/vietdt/buildout.extendssubs.git
$ cd buildout.extendssubs/
Update buildout.cfg to list the package directory as a develop egg to be built.
[buildout]
develop = .
parts =
It's a bit tricky when running the buildout once with the develop egg defined but without the extension option. This is because extensions are loaded before the buildout creates develop eggs. We needed to use a separate buildout run to create the develop egg.
$ python bootstrap.py
$ ./bin/buildout -v
Now we can add the extensions and extends-subs options. Normally, when eggs are loaded from the network (TODO), we wouldn’t need the previous step.
[buildout]
develop = .
extensions = buildout.extendssubs
extends-subs = ${:LEVEL}.cfg
Then run the buildout again with assignment option set from command-line.
$ ./bin/buildout -v buildout:LEVEL=staging