Create OpenAPI specs for rest API

[ioggstream]

I wish

• to have an openapi spec for geoportal-server
• the openapi.yaml represents in a usable way the informations in https://github.com/Esri/geoportal-server/wiki/REST-API-Syntax

[mhogeweg]

out of curiosity: do you have client applications that would use this openapi spec to auto-discover geoportal search capabilities? what is the goal of doing this?

[gcampanile]

I have a client that explicitly asked for an OpenAPI spec; it's a public authority and the reason is to provide a common API to query all their services.

[ioggstream]

having a standardized interface:

• clarifies usage pattern with multiple examples
• can be validated via a linter
• allows api to be viewable from a catalog (eg. https://api.gouv.fr/api/le-taxi.html)