Comment 18 for bug 1625402

I guess what I was trying to get at was, you have to e.g. set usernames/passwords in your configuration files before services relying on Keystone become useful. But I don't think anyone would call defining such variables "non-default" behavior.

My uncertainty is this: is "work_dir" usually set by reasonable operators to make Glance work as expected? I imagine that Glance avoids setting a default because 1) it can trigger significant disk usage for whatever folder is selected, and 2) Glance can't always predict what device will be the right one to choose to accommodate that disk usage, so rather than accidentally filling e.g. your /usr/ drive, it forces you to define it yourself. This is similar to services not necessarily specifying defaults for Keystone creds, since it would be unreasonable to assume that "admin/admin" would work by default anyway.