[AKS] Allow aks nodepool update --node-taints (#4363)

* allow edit taints and add test

* add missing parameter

* change var name

* .get_output_in_json()

* give value

* try fix'

* fix test

* address comments

src/aks-preview/azext_aks_preview/_help.py

@@ -977,7 +977,7 @@
           short-summary: "Describes how VMs are added to or removed from nodepools."
         - name: --node-taints
           type: string
-          short-summary: The node taints for the node pool. You can't change the node taints through CLI after the node pool is created.
+          short-summary: The node taints for the node pool.
         - name: --priority
           type: string
           short-summary: The priority of the node pool.
@@ -1100,6 +1100,9 @@
         - name: --labels
           type: string
           short-summary: The node labels for the node pool. See https://aka.ms/node-labels for syntax of labels.
+        - name: --node-taints
+          type: string
+          short-summary: The node taints for the node pool.
     examples:
       - name: Enable cluster-autoscaler within node count range [1,5]
         text: az aks nodepool update --enable-cluster-autoscaler --min-count 1 --max-count 5 -g MyResourceGroup -n nodepool1 --cluster-name MyManagedCluster

src/aks-preview/azext_aks_preview/_params.py

@@ -244,7 +244,7 @@ def load_arguments(self, _):
             c.argument('enable_fips_image', action='store_true')
             c.argument('enable_cluster_autoscaler', options_list=["--enable-cluster-autoscaler", "-e"], action='store_true')
             c.argument('scale_down_mode', arg_type=get_enum_type([CONST_SCALE_DOWN_MODE_DELETE, CONST_SCALE_DOWN_MODE_DEALLOCATE]))
-            c.argument('node_taints', type=str, validator=validate_taints)
+            c.argument('node_taints', validator=validate_taints)
             c.argument('priority', arg_type=get_enum_type([CONST_SCALE_SET_PRIORITY_REGULAR, CONST_SCALE_SET_PRIORITY_SPOT]), validator=validate_priority)
             c.argument('eviction_policy', arg_type=get_enum_type([CONST_SPOT_EVICTION_POLICY_DELETE, CONST_SPOT_EVICTION_POLICY_DEALLOCATE]), validator=validate_eviction_policy)
             c.argument('spot_max_price', type=float, validator=validate_spot_max_price)
@@ -282,6 +282,7 @@ def load_arguments(self, _):
         c.argument('mode', arg_type=get_enum_type([CONST_NODEPOOL_MODE_SYSTEM, CONST_NODEPOOL_MODE_USER]))
         c.argument('max_surge', type=str, validator=validate_max_surge)
         c.argument('labels', nargs='*', validator=validate_nodepool_labels)
+        c.argument('node_taints', validator=validate_taints)
 
     with self.argument_context('aks addon show') as c:
         c.argument('addon', options_list=['--addon', '-a'], validator=validate_addon)

src/aks-preview/azext_aks_preview/custom.py

@@ -1767,19 +1767,32 @@ def aks_agentpool_update(cmd,   # pylint: disable=unused-argument
                          max_surge=None,
                          mode=None,
                          labels=None,
+                         node_taints=None,
                          no_wait=False):
 
     update_autoscaler = enable_cluster_autoscaler + \
         disable_cluster_autoscaler + update_cluster_autoscaler
 
-    if (update_autoscaler != 1 and not tags and not scale_down_mode and not mode and not max_surge and labels is None):
+    if (update_autoscaler != 1 and not tags and not scale_down_mode and not mode and not max_surge and labels is None and node_taints is None):
         raise CLIError('Please specify one or more of "--enable-cluster-autoscaler" or '
                        '"--disable-cluster-autoscaler" or '
                        '"--update-cluster-autoscaler" or '
-                       '"--tags" or "--mode" or "--max-surge" or "--scale-down-mode" or "--labels"')
+                       '"--tags" or "--mode" or "--max-surge" or "--scale-down-mode" or "--labels" or "--node-taints')
 
     instance = client.get(resource_group_name, cluster_name, nodepool_name)
 
+    if node_taints is not None:
+        taints_array = []
+        if node_taints != '':
+            for taint in node_taints.split(','):
+                try:
+                    taint = taint.strip()
+                    taints_array.append(taint)
+                except ValueError:
+                    raise InvalidArgumentValueError(
+                        'Taint does not match allowed values. Expect value such as "special=true:NoSchedule".')
+        instance.node_taints = taints_array
+
     if min_count is None or max_count is None:
         if enable_cluster_autoscaler or update_cluster_autoscaler:
             raise CLIError('Please specify both min-count and max-count when --enable-cluster-autoscaler or '