Instance & channel_strategy validation (#1233)

* compare cloud instance with channel strategy

* fix unit tests

* error wording

---------

Co-authored-by: Jessie Yu <[email protected]>

Author: kt474

qiskit_ibm_runtime/api/clients/runtime.py

@@ -268,13 +268,13 @@ def list_backends(
         """
         return self._api.backends(hgp=hgp, channel_strategy=channel_strategy)["devices"]
 
-    def cloud_instance(self) -> bool:
+    def is_qctrl_enabled(self) -> bool:
         """Returns a boolean of whether or not the instance has q-ctrl enabled.
 
         Returns:
             Boolean value.
         """
-        return self._api.cloud_instance()
+        return self._api.is_qctrl_enabled()
 
     def backend_configuration(self, backend_name: str) -> Dict[str, Any]:
         """Return the configuration of the IBM backend.

qiskit_ibm_runtime/api/rest/runtime.py

@@ -230,7 +230,7 @@ def backends(
             params["channel_strategy"] = channel_strategy
         return self.session.get(url, params=params, timeout=timeout).json()
 
-    def cloud_instance(self) -> bool:
+    def is_qctrl_enabled(self) -> bool:
         """Return boolean of whether or not the instance has q-ctrl enabled.
 
         Returns:

qiskit_ibm_runtime/qiskit_runtime_service.py

@@ -317,11 +317,21 @@ def _validate_channel_strategy(self) -> None:
         instance do not match.
 
         """
+        qctrl_enabled = self._api_client.is_qctrl_enabled()
         if self._channel_strategy == "q-ctrl":
-            qctrl_enabled = self._api_client.cloud_instance()
             if not qctrl_enabled:
                 raise IBMNotAuthorizedError(
-                    "This account is not authorized to use ``q-ctrl`` as a channel strategy."
+                    "The instance passed in is not compatible with Q-CTRL channel strategy. "
+                    "Please switch to or create an instance with the Q-CTRL strategy enabled. "
+                    "See https://cloud.ibm.com/docs/quantum-computing?"
+                    "topic=quantum-computing-get-started for more information"
+                )
+        else:
+            if qctrl_enabled:
+                raise IBMNotAuthorizedError(
+                    "The instance passed in is only compatible with Q-CTRL performance "
+                    "management strategy. "
+                    "To use this instance, set channel_strategy='q-ctrl'."
                 )
 
     def _discover_cloud_backends(self) -> Dict[str, "ibm_backend.IBMBackend"]:

releasenotes/notes/q-ctrl-instance-check-46181d51f16d18bc.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    If a cloud instance that is `q-ctrl` enabled is used while `q-ctrl` is not 
+    passed in as the `channel_strategy`, an error will be raised.

test/unit/mock/fake_runtime_client.py

@@ -285,6 +285,10 @@ def set_job_classes(self, classes):
             classes = [classes]
         self._job_classes = classes
 
+    def is_qctrl_enabled(self):
+        """Return whether or not channel_strategy q-ctrl is enabled."""
+        return False
+
     def set_final_status(self, final_status):
         """Set job status to passed in final status instantly."""
         self._final_status = final_status