Specify schema of YAML files

[umairidris]

Today, it is not possible to know the schema of the rules yaml files unless one looks at examples or digs into the code.

It would be great if a schema such as https://github.com/GoogleCloudPlatform/healthcare/blob/master/deploy/templates/data_project.py.schema could be defined.

[umairidris]

Possible solution: convert to json dict and use https://github.com/Julian/jsonschema.

[forseti-security-waffle-bot]

Hi @umairidris, this would be great to have! However, we would want the schema to be proto-based.
For example, the proto syntax should describe the fields in the yaml file, their types, and in the case of an enum, their possible values. Submessages (sub dictionaries or sub lists) should be encoded as well.

Would you be able to help us define the sample schema file described in this issue?