[DM-41830] Add some sanity checking on siav2 labels

src/lsst/rsp/service.py

@@ -1,12 +1,47 @@
+import os
+
 import pyvo
 from pyvo.dal import SIA2Service
 
 from .utils import get_pyvo_auth, get_service_url
 
-def get_siav2_service(*args: str) -> pyvo.dal.SIA2Service:
+
+LSST_CLOUD = [
+    "https://data.lsst.cloud",
+    "https://data-int.lsst.cloud", 
+    "https://data-dev.lsst.cloud"
+]
+
+USDF = [
+    "https://usdf-rsp.slac.stanford.edu/",
+    "https://usdf-rsp-dev.slac.stanford.edu/"
+]
+
+
+def get_siav2_service(*args: str) -> SIA2Service:
+    """Return a configured SIA2Service object that is ready to use."""
+    fqdn = os.environ["EXTERNAL_INSTANCE_URL"]
+
     if len(args) == 0:
-        ds = "dp0.2"
-    elif args == "latiss":
-        ds = "latiss"
+        # Use the default for each environment
+        if fqdn in LSST_CLOUD:
+            label = "dp0.2"
+        elif fqdn in USDF:
+            label = "latiss"
+        else:
+            raise Exception("Unknown environment" + fqdn)
+    else:
+        label = args[0]
+
+    # If a label is passed, check that.
+    if label not in ["dp0.2", "latiss"]:
+        raise Exception(label + " is not a valid siav2 label")
+
+    if label == "latiss" and fqdn not in USDF:
+        raise Exception(label + " data not available at your location")
+    if label == "dp0.2" and fqdn not in LSST_CLOUD:
+        raise Exception(label + " data not available at your location")
 
+    # No matter what, we've only got one sia server per environment
+    # so for now just do some checking.
     return SIA2Service(get_service_url("siav2"), get_pyvo_auth())