next, prev and self links returned from /search endpoint ignore root_path settings

[Kirill888]

This is on main branch.

When App is configured with a prefix, in our case /stac

app = FastAPI(root_path="/stac", lifespan=lifespan)

and we use search in POST mode with something like this:

DATA='{"datetime":"2021-01-01T00:00:00Z/2021-02-28T23:59:59Z","collections":["agera5"]}'
curl -v -s \
  -H 'Origin: https://somesite.org' \
  -H 'Content-Type: application/json' \
  -X POST -d "$DATA" \
  "https://XXXX.lambda-url.eu-central-1.on.aws/stac/search" | tee response.json | jq '.links'

Links for next and self returned from that endpoint are missing configured root_path prefix.

"links:" [
  {
    "rel": "next",
    "type": "application/geo+json",
    "method": "POST",
    "href": "https://XXXX.lambda-url.eu-central-1.on.aws/search",
    "body": {
      "datetime": "2021-01-01T00:00:00Z/2021-02-28T23:59:59Z",
      "collections": [
        "agera5"
      ],
      "token": "next:agera5:agera5-20210219"
    }
  },
  {
    "rel": "root",
    "type": "application/json",
    "href": "https://XXXX.lambda-url.eu-central-1.on.aws/stac/"
  },
  {
    "rel": "self",
    "type": "application/json",
    "href": "https://XXXX.lambda-url.eu-central-1.on.aws/search"
  }
]

Note that root link is correct in the response above, so configuration is being picked up.

My guess that error is here:

stac-fastapi-pgstac/stac_fastapi/pgstac/models/links.py

Lines 141 to 148 in df4c12a

	if method == "POST":
	return {
	"rel": Relations.next,
	"type": MimeTypes.geojson,
	"method": method,
	"href": f"{self.request.url}",
	"body": {**self.request.postbody, "token": f"next:{self.next}"},
	}

Raw request.url is used without calling self.resolve(..) to patch it for external view of the API endpoint.