Fix/forwarding headers

[captaincoordinates]

Related Issue(s):

• Support Forwarded and X-Forwarded-* HTTP headers #414

Description:
Support Forwarded and X-Forwarded-* headers so that stac-fastapi responses contain links that accommodate load balancer or proxy configurations.

Note: there is duplication of both code and concepts across the pgstac and sqlalchemy applications. Each application has its own method of generating links (I don't know why this logic wasn't shared) and therefore each has a copy of the get_base_url_from_request function here. This explains why this PR has duplicate code and does not follow a more sensible DRY strategy - the repo really isn't set up for it and I am not looking to make large-scale refactoring changes here.

PR Checklist:

• Code is formatted and linted (run pre-commit run --all-files)
• Tests pass (run make test)
• Documentation has been updated to reflect changes, if applicable, and docs build successfully (run make docs)
• Changes are added to the CHANGELOG.

[gnosys-ccoupal]

Looks great. I will give this fix a try.. One thing I noted.. base_url is used in a few times in stac_fastapi/types/stac_fastapi/types/core.py as part of landing page. Should these be addressed as well?

[captaincoordinates]

base_url is used in a few times in stac_fastapi/types/stac_fastapi/types/core.py as part of landing page. Should these be addressed as well?

@gnosys-ccoupal yes, I didn't see that, and it complicates things. Currently I have an implementation in both the pgstac and sqlalchemy application, but stac_fastapi/types/stac_fastapi/types/core.py is not part of either application and therefore doesn't have access to the header logic.

Perhaps the better solution is to introduce a middleware in stac_fastapi/api/middleware.py that modifies request.base_url, so that no additional logic is required outside the middleware.

[captaincoordinates]

Converted to Draft PR while working on a suitable middleware approach.

[captaincoordinates]

No longer draft status - ready to review with new middleware approach that covers all response links

[geospatial-jeff]

This LGTM! Thanks for writing solid tests. Because this feature is talked about a lot I'm going to write some unittests covering the middleware itself and then get this merged.