Describe the bug
az aks nodepool upgrade --max-unavailable accepts the flag, validates it, and documents it in help text, but never applies it to the agent pool before sending the PUT request. The value is silently dropped.
Related command
(from https://learn.microsoft.com/en-us/azure/aks/stateful-workload-upgrades#step-3-upgrade-node1-former-primary)
az aks nodepool upgrade \
--resource-group myRG \
--cluster-name myCluster \
--name myPool \
--kubernetes-version 1.29.0 \
--max-surge 0 \
--max-unavailable 1Errors
This bug would not produce any error message.
Issue script & Debug output
This issue was discovered through code review of dev.
Expected behavior
az aks nodepool upgrade should pass --max-unavailable through to the PUT request.
Environment Summary
This issue was discovered through code review of dev.
Additional context
Line numbers below are as of adb78953b2b0c0debe5be51aa02262baacba0626.
Root cause
--max-unavailable was added in #31510 (commit cb14a97). That PR correctly wired up max_unavailable in:
- The function signature (
custom.py, line 3087)
- The
--node-image-only mutual-exclusivity check (custom.py, line 3110)
- Help text (
_help.py, line 2195)
- Parameter registration (
_params.py, line 1134)
- The
nodepool add and nodepool update decorators (agentpool_decorator.py, lines 2036–2038 and 2518–2520)
But aks_agentpool_upgrade() in custom.py does not use the decorator pattern — it directly assigns upgrade settings to the instance (lines 3159–3169). The assignment for max_unavailable was never added:
# custom.py lines 3159-3169
if not instance.upgrade_settings:
instance.upgrade_settings = AgentPoolUpgradeSettings()
if max_surge:
instance.upgrade_settings.max_surge = max_surge
if drain_timeout:
instance.upgrade_settings.drain_timeout_in_minutes = drain_timeout
if isinstance(node_soak_duration, int) and node_soak_duration >= 0:
instance.upgrade_settings.node_soak_duration_in_minutes = node_soak_duration
if undrainable_node_behavior:
instance.upgrade_settings.undrainable_node_behavior = undrainable_node_behavior
# max_unavailable: missingThe test added in #31510 covers nodepool add and nodepool update but explicitly skips nodepool upgrade (# actually running an upgrade is too expensive for these tests.).
Fix
Add the missing assignment after line 3169:
if max_unavailable:
instance.upgrade_settings.max_unavailable = max_unavailable
Describe the bug
az aks nodepool upgrade --max-unavailableaccepts the flag, validates it, and documents it in help text, but never applies it to the agent pool before sending the PUT request. The value is silently dropped.Related command
(from https://learn.microsoft.com/en-us/azure/aks/stateful-workload-upgrades#step-3-upgrade-node1-former-primary)
az aks nodepool upgrade \ --resource-group myRG \ --cluster-name myCluster \ --name myPool \ --kubernetes-version 1.29.0 \ --max-surge 0 \ --max-unavailable 1Errors
This bug would not produce any error message.
Issue script & Debug output
This issue was discovered through code review of
dev.Expected behavior
az aks nodepool upgradeshould pass--max-unavailablethrough to the PUT request.Environment Summary
This issue was discovered through code review of
dev.Additional context
Line numbers below are as of adb78953b2b0c0debe5be51aa02262baacba0626.
Root cause
--max-unavailablewas added in #31510 (commit cb14a97). That PR correctly wired upmax_unavailablein:custom.py, line 3087)--node-image-onlymutual-exclusivity check (custom.py, line 3110)_help.py, line 2195)_params.py, line 1134)nodepool addandnodepool updatedecorators (agentpool_decorator.py, lines 2036–2038 and 2518–2520)But
aks_agentpool_upgrade()incustom.pydoes not use the decorator pattern — it directly assigns upgrade settings to the instance (lines 3159–3169). The assignment formax_unavailablewas never added:The test added in #31510 covers
nodepool addandnodepool updatebut explicitly skipsnodepool upgrade(# actually running an upgrade is too expensive for these tests.).Fix
Add the missing assignment after line 3169: