On 07/01/2013 05:52 PM, Clint Byrum wrote: > Last week I went to use oslo.config in a utility I am writing called > os-collect-config[1]... > > While running unit tests on the main() method that is used for the CLI, > I was surprised to find that my unit tests were picking up values from > a config file I had created just as a test. The tests can be fixed to > disable config file lookups, but what was more troublesome was that the > config file was overriding values I was passing in as sys.argv. > > I have read the thread[2] which suggest that CLI should defer to config > file because config files are somehow less permanent than the CLI. > > I am writing today to challenge that notion, and also to suggest that even > if that is the case, it is inappropriate to have oslo.config operate in > such a profoundly different manner than basically any other config library > or system software in general use. CLI options are _for config files_ > and if packagers are shipping configurations in systemd unit files, > upstart jobs, or sysvinits, they are doing so to control the concerns > of that particular invocation of whatever command they are running, > and not to configure the software entirely. > > CLI args are by definition ephemeral, even if somebody might make them > "permanent" in their system, I doubt any packager would then expect that > these CLI args would be overridden by any config files. This default is > just wrong, and needs to be fixed.
+1 When I read "Option values in config files override those on the command line." in the cfg.py docstring I thought surely that must be a typo because it's it's the opposite of years of established practice. I think the following captures the expected behavior > I was also confused by the ordering in this list, though when I read more > carefully it seems to agree with me: > >> - Default value in source code >> - Overridden by value in config file >> - Overridden by value in environment variable >> - Overridden by value given as command line option > > I'd like to rewrite that list as > > - Value given as a command line option > - Failing that, value in environment variable > - Failing that, value in config file > - Failing that, default value in source code > John _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
