STAC self links get garbled when eoAPI STAC API is behind an API gateway

[j08lue]

When accessing https://eoapi.apx.develop.eoepca.org/stac/ I still get a self link with port number 9443: https://eoapi.apx.develop.eoepca.org:9443/stac/

When accessing the "old" URL https://eoapi.develop.eoepca.org/stac/ however, I get a correct self link.

Acceptance criteria

• Self links are correct also when the STAC API is behind the IAM-deployed API gateway

[pantierra]

I've looked into this, and it seems we have to fix this on the gateway (APISIX) level.

The appended port issue is most likely related to an APISIX problem, which @w-scho appears to be actively addressing already. Additionally, at the stac-fastapi level, it is deliberately discouraged (1, 2) to set the base-url hard-coded.

[w-scho]

APISIX seems to always add an X-Forwarded-Port header with the value set to its container port (here: 9443). This is correct from APISIX's local perspective, but wrong from the global one.
We had tried to apply a simple gobal workaround for this, but apparently it did not cover all relevant cases.
Now after the demo event is over, I dared to experiment again and temporarily added an ApisixGlobalRule that applies the workaround from the Keycloak route globally. This actually seems to fix the problem. I hope that it does not cause any undesired side effects. If no complaints arise during the next few days, I will make the new rule permanent.