Support root path to enable requesting from a different route than root

Author: alukach

src/stac_auth_proxy/app.py

@@ -67,7 +67,10 @@ async def lifespan(app: FastAPI):
     app = FastAPI(
         openapi_url=None,  # Disable OpenAPI schema endpoint, we want to serve upstream's schema
         lifespan=lifespan,
+        root_path=settings.root_path,
     )
+    if app.root_path:
+        logger.debug("Mounted app at %s", app.root_path)
 
     #
     # Handlers (place catch-all proxy handler last)

src/stac_auth_proxy/config.py

@@ -38,6 +38,7 @@ class Settings(BaseSettings):
     oidc_discovery_url: HttpUrl
     oidc_discovery_internal_url: HttpUrl
 
+    root_path: str = ""
     wait_for_upstream: bool = True
     check_conformance: bool = True
     enable_compression: bool = True