From c0e0a4e4d15b2487817834d6dfb1494273308735 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 8 May 2026 04:44:47 +0000
Subject: [PATCH 1/3] Initial plan


From 84840997329c059ec5143ed71b1327ad715fd916 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 8 May 2026 04:49:34 +0000
Subject: [PATCH 2/3] fix(aks): improve outbound type update error for managed
 vnet clusters

Agent-Logs-Url: https://github.com/Azure/azure-cli/sessions/89434938-59be-4bd2-8316-b23911d26c91

Co-authored-by: a0x1ab <59631311+a0x1ab@users.noreply.github.com>
---
 .../acs/managed_cluster_decorator.py           | 14 ++++++++++++--
 .../latest/test_managed_cluster_decorator.py   | 18 ++++++++++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py b/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py
index 6efebb3201c..c347c9ecc28 100644
--- a/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py
+++ b/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py
@@ -2366,13 +2366,23 @@ def get_sku_name(self) -> str:
                 skuName = CONST_MANAGED_CLUSTER_SKU_NAME_BASE
         return skuName
 
-    @staticmethod
-    def _raise_missing_vnet_subnet_for_outbound_type(outbound_type: str, sku_name: str) -> None:
+    def _raise_missing_vnet_subnet_for_outbound_type(self, outbound_type: str, sku_name: str) -> None:
         if outbound_type == CONST_OUTBOUND_TYPE_USER_DEFINED_ROUTING:
             subnet_requirement = "a route table with egress rules"
         else:
             subnet_requirement = "a NAT gateway with outbound ips"
 
+        if self.decorator_mode == DecoratorMode.UPDATE:
+            raise InvalidArgumentValueError(
+                "Updating outbound type to {outbound_type} is only supported for clusters created with "
+                "--vnet-subnet-id. Clusters using an AKS-managed VNet can't be updated to this outbound type. "
+                "Please refer to "
+                "https://learn.microsoft.com/en-us/azure/aks/egress-outboundtype#updating-outboundtype-after-cluster-creation "  # pylint:disable=line-too-long
+                "for more details.".format(
+                    outbound_type=outbound_type,
+                )
+            )
+
         if sku_name == CONST_MANAGED_CLUSTER_SKU_NAME_AUTOMATIC:
             raise RequiredArgumentMissingError(
                 "--vnet-subnet-id must be specified for {outbound_type}. For an Automatic cluster "
diff --git a/src/azure-cli/azure/cli/command_modules/acs/tests/latest/test_managed_cluster_decorator.py b/src/azure-cli/azure/cli/command_modules/acs/tests/latest/test_managed_cluster_decorator.py
index be04d278208..ab6a217e15a 100644
--- a/src/azure-cli/azure/cli/command_modules/acs/tests/latest/test_managed_cluster_decorator.py
+++ b/src/azure-cli/azure/cli/command_modules/acs/tests/latest/test_managed_cluster_decorator.py
@@ -2020,6 +2020,24 @@ def test_get_outbound_type(self):
         ctx_1.attach_mc(mc)
         self.assertEqual(ctx_1.get_outbound_type(), "test_outbound_type")
 
+        ctx_1_1 = AKSManagedClusterContext(
+            self.cmd,
+            AKSManagedClusterParamDict(
+                {
+                    "outbound_type": CONST_OUTBOUND_TYPE_USER_DEFINED_ROUTING,
+                }
+            ),
+            self.models,
+            DecoratorMode.UPDATE,
+        )
+        ctx_1_1.agentpool_context = mock.MagicMock()
+        ctx_1_1.agentpool_context.get_vnet_subnet_id.return_value = None
+        with self.assertRaisesRegex(
+            InvalidArgumentValueError,
+            "only supported for clusters created with --vnet-subnet-id",
+        ):
+            ctx_1_1.get_outbound_type()
+
         # invalid parameter
         ctx_2 = AKSManagedClusterContext(
             self.cmd,

From 3638afdec2e0524138682b7225ea36b598e308ac Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 8 May 2026 04:50:25 +0000
Subject: [PATCH 3/3] chore(aks): refine outbound type update error string
 formatting

Agent-Logs-Url: https://github.com/Azure/azure-cli/sessions/89434938-59be-4bd2-8316-b23911d26c91

Co-authored-by: a0x1ab <59631311+a0x1ab@users.noreply.github.com>
---
 .../cli/command_modules/acs/managed_cluster_decorator.py    | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py b/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py
index c347c9ecc28..e46511f1097 100644
--- a/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py
+++ b/src/azure-cli/azure/cli/command_modules/acs/managed_cluster_decorator.py
@@ -2374,13 +2374,11 @@ def _raise_missing_vnet_subnet_for_outbound_type(self, outbound_type: str, sku_n
 
         if self.decorator_mode == DecoratorMode.UPDATE:
             raise InvalidArgumentValueError(
-                "Updating outbound type to {outbound_type} is only supported for clusters created with "
+                f"Updating outbound type to {outbound_type} is only supported for clusters created with "
                 "--vnet-subnet-id. Clusters using an AKS-managed VNet can't be updated to this outbound type. "
                 "Please refer to "
                 "https://learn.microsoft.com/en-us/azure/aks/egress-outboundtype#updating-outboundtype-after-cluster-creation "  # pylint:disable=line-too-long
-                "for more details.".format(
-                    outbound_type=outbound_type,
-                )
+                "for more details."
             )
 
         if sku_name == CONST_MANAGED_CLUSTER_SKU_NAME_AUTOMATIC: