[ENH] allow passing default attr to dask worker profiles

src/_nebari/stages/kubernetes_services/__init__.py

@@ -178,6 +178,7 @@ class DaskWorkerProfile(schema.Base):
     worker_memory: str
     worker_threads: int = 1
     model_config = ConfigDict(extra="allow")
+    default: bool = False
 
 
 class Profiles(schema.Base):
@@ -232,6 +233,17 @@ def check_default(cls, value):
             )
         return value
 
+    @field_validator("dask_worker")
+    @classmethod
+    def assert_single_default_dask(cls, value):
+        """
+        Check if only one default value is present in the dask profiles
+        """
+        default = [attrs["default"] for attrs in value if "default" in attrs]
+        if default.count(True) > 1:
+            raise TypeError("Multiple default Dask worker profiles are not supported.")
+        return value
+
 
 class CondaEnvironment(schema.Base):
     name: str

src/_nebari/stages/kubernetes_services/template/modules/kubernetes/services/dask-gateway/files/gateway_config.py

@@ -261,6 +261,14 @@ def user_options(user):
             continue
         conda_environments.append(f"{namespace}/{namespace}-{name}")
 
+    def parse_default_profile(profiles: dict):
+        profiles_keys = profiles.keys()
+        for profile in profiles_keys:
+            if profiles[profile].get("default", False):
+                return profile
+            continue
+        return list(profiles_keys)[0]
+
     args = []
     if conda_environments:
         args += [
@@ -276,7 +284,7 @@ def user_options(user):
             Select(
                 "profile",
                 list(config["profiles"].keys()),
-                default=list(config["profiles"].keys())[0],
+                default=parse_default_profile(config["profiles"]),
                 label="Cluster Profile",
             )
         ]