why do we need to exclude those fields? There is a similar method serialize_input in ExternalResource, and to serialize json, can directly call resource.json( instead of resource.dict( then json.dumps

• These fields are not expected in the module input. Since the overrides parameter doesn't have a schema, all the overridden parameters are passed to the terraform object directly (the same way as terraform-resources). So all parameters not expected in the input shall be removed.

• I changed the call to resource.json() and removed the method in ExternalResource (this was used in an old implementation when the INPUT was passed as an env var)

Is there a way to ignore unexpected input or define a clear mapping? Otherwise we have to remember edit this part whenever we put new fields in data

I cannot think of anything to do that as we want the ability to add additional fields in the overrides.
There should not be a lot of changes here since only "logical" parameters need to be introduced.
I agree though, I'll try to overcome this or at least have a way to detect it with a test or something.