I mean that configuring an API Gateway in file based mode means it will behave differently because it gets all its configs from the file system instead of the dashboard.
Gathering analytics would also not work properly, you could set up the pump to send data to mongo and use the dashboard to read that, but all the management features wouldn't work. If the gateways are nowhere near the dashboard or mongo DB then it won't work at all, Yuko need our multi-DC system or our hybrid for that.
Which docker image are you referring to? The standard gateway docker image? If you are using it in conjunction with the dashboard gen the gateway REST API is superceded by the dashboard one.
If using on its own and configured to use file-based configuration then the REST API of the gateway will become fully active again.
If you are using our hybrid container, then all interactions and api calls should be via our cloud.