Validate instance types for GCP

src/_nebari/provider/cloud/google_cloud.py

@@ -51,6 +51,22 @@ def regions() -> Set[str]:
     return {region.name for region in response}
 
 
+@functools.lru_cache()
+def instances(region: str) -> Set[str]:
+    """Return a set of available compute instances in a region."""
+    credentials, project_id = load_credentials()
+    zones_client = compute_v1.services.region_zones.RegionZonesClient(
+        credentials=credentials
+    )
+    instances_client = compute_v1.InstancesClient(credentials=credentials)
+
+    return {
+        instance.machine_type.split("/")[-1]
+        for zone in zones_client.list(project=project_id, region=region)
+        for instance in instances_client.list(project=project_id, zone=zone.name)
+    }
+
+
 @functools.lru_cache()
 def kubernetes_versions(region: str) -> List[str]:
     """Return list of available kubernetes supported by cloud provider. Sorted from oldest to latest."""

src/_nebari/stages/infrastructure/__init__.py

@@ -399,6 +399,21 @@ def _check_input(cls, data: Any) -> Any:
             raise ValueError(
                 f"\nInvalid `kubernetes-version` provided: {data['kubernetes_version']}.\nPlease select from one of the following supported Kubernetes versions: {available_kubernetes_versions} or omit flag to use latest Kubernetes version available."
             )
+
+        # check if instances are valid
+        available_instances = google_cloud.instances(data["region"])
+        if "node_groups" in data:
+            for _, node_group in data["node_groups"].items():
+                instance = (
+                    node_group["instance"]
+                    if hasattr(node_group, "__getitem__")
+                    else node_group.instance
+                )
+                if instance not in available_instances:
+                    raise ValueError(
+                        f"Google Cloud Platform instance {instance} not one of available instance types={available_instances}"
+                    )
+
         return data