stop accepting empty body in /attach API

[problame]

PR #4255 adds the attach-time tenant config capability, but continues to accept the default tenant config for backwards-comaptibility reasons.

Once the corresponding cloud.git work to use attach-time tenant config is done, we should error out if the request body is empty and instead require a correct TenantAttachRequest object in the body.

Required work (in correct order)

• Adjust test cases that currently use plain detach + attach (if they don't care, they can continue to use an empty config={}
  • Consider requiring the config as an argument to make callers aware that they need to think about this.
• Make the change
  • ... in tenant_attach_handler
  • ... adjust openapi yaml
  • ... and adjust the test_empty_body added in attach-time tenant config #4255 to expect failure (=> use NegativeEnv)
  • remove now-unused json_request_or_empty_body

[problame]

This will be obsoleted by the move to the upsert location endpoint.

[hlinnaka]

If I understand correctly, https://github.com/neondatabase/cloud/pull/10927 removed the last calls of the /attach endpoint from the control plane. Can we remove it from the pageserver now?

I think the python tests are still using it though (tenant_attach in test_runner/fixtures/pageserver/http.py). Should they be changed to use the new API? What exactly is the corresponding new API?

[problame]

If I understand correctly, https://github.com/neondatabase/cloud/pull/10927 removed the last calls of the /attach endpoint from the control plane. Can we remove it from the pageserver now?

Yeah, my understanding also is that there shouldn't be any more production users of /attach.

I think the python tests are still using it though (tenant_attach in test_runner/fixtures/pageserver/http.py). Should they be changed to use the new API? What exactly is the corresponding new API?

.../location_config is the new API.

Let's take this conversation into the team channel.