support the cookie as token source (token_from) for JWT authenticator

[ngrigoriev]

Is your feature request related to a problem? Please describe.

According to the Oathkeeper documentation the "jwt" authenticator can fetch the token from either a named HTTP header or from the query parameter. At the same time, "oauth2_introspection" authenticator supports the named cookie as source. It would be great to support the cookie source for "jwt" authenticator as well.

Describe the solution you'd like

I may be wrong but it looks like it may be already supported, authenticator_jwt.go calls helper.BearerTokenFromRequest() to get the token and this function does support all 3 sources. Is it possible that this is just a missed point in the documentation?

Thanks!

[aeneasr]

Yes, I believe this is just a docs issue!

[ngrigoriev]

I am trying to add the unit tests for this + update the schema. Turns out, both authenticator_oauth2_introspection_test.go and authenticator_jwt_test.go are missing the tests for the cookie case and the schema for the "jwt" authenticator is missing this oneof element too. Will provider a PR soon.