From c0e82c87e9d93c8bfb597776aa25725ff4f88832 Mon Sep 17 00:00:00 2001
From: deveshdama <87668846+deveshdama@users.noreply.github.com>
Date: Wed, 6 Mar 2024 23:53:04 -0800
Subject: [PATCH] [AKS] `az aks mesh get-upgrades`: Fix command failure with a
 traceback if ASM addon is disabled (#28507)

---
 .../azure/cli/command_modules/acs/custom.py   | 29 ++++++++++++-------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/azure-cli/azure/cli/command_modules/acs/custom.py b/src/azure-cli/azure/cli/command_modules/acs/custom.py
index 0bc0c8c183f..80ae7f79b18 100644
--- a/src/azure-cli/azure/cli/command_modules/acs/custom.py
+++ b/src/azure-cli/azure/cli/command_modules/acs/custom.py
@@ -2833,6 +2833,17 @@ def aks_mesh_get_revisions(
     return None
 
 
+def check_iterator(iterator):
+    import itertools
+    try:
+        first = next(iterator)
+    except StopIteration:   # iterator is empty
+        return True, iterator
+    except TypeError:       # iterator is not iterable, e.g. None
+        return True, iterator
+    return False, itertools.chain([first], iterator)
+
+
 def aks_mesh_get_upgrades(
         cmd,
         client,
@@ -2840,16 +2851,14 @@ def aks_mesh_get_upgrades(
         name
 ):
     upgradeProfiles = client.list_mesh_upgrade_profiles(resource_group_name, name)
-    # 'upgradeProfiles' is an ItemPaged object
-    upgrades = []
-    # Iterate over items within pages
-    for page in upgradeProfiles.by_page():
-        for item in page:
-            upgrades.append(item)
-
-    if upgrades:
-        return upgrades[0].properties
-
+    is_empty, upgradeProfiles = check_iterator(upgradeProfiles)
+    if is_empty:
+        logger.warning("No mesh upgrade profiles found for the cluster '%s' " +
+                       "in the resource group '%s'.", name, resource_group_name)
+        return None
+    upgrade = next(upgradeProfiles, None)
+    if upgrade:
+        return upgrade.properties
     return None