On Mon, 2011-12-05 at 15:32 -0800, Andy Smith wrote: > Took a look over the wiki for this. The approach is very similar to one > I've used recently so I wanted to bring up something that looks like it may > have been overlooked. > > In testing it is frequent practice that you want to ensure global config > state and somehow overwrite global config state on the fly (for example > when you have dynamic ports being assigned to a service), passing config > dicts around everywhere makes this task a bit harder. My solution was to > force all instances being handed an options dict to assign it to the > .options attribute on itself, and to use a common name for chained > applications so that it is possible to traverse the tree: > > https://github.com/termie/keystonelight/blob/master/keystonelight/test.py#L107 Glance already was passing a config dict around so, for tests, I found it quite handy to have a little helper which actually wrote out a temporary config file with overrides: https://github.com/markmc/glance/blob/31bcda2f09d49a8214fc1a56ffc3543fcad590aa/glance/tests/utils.py#L32 With Nova, it'll be quite a challenge to get to a point where we're not using a global variable for accessing config. For Nova tests, I added set_default() and set_override() methods: https://github.com/markmc/nova/blob/101dfcb0fe4f2c5db20e9c8305e8ca87bb5b7e54/nova/common/cfg.py#L855 Cheers, Mark.