[AKS] az aks nodepool delete-machines: Add support to delete specif…

…ic machines in an agent pool (#29921)

src/azure-cli/azure/cli/command_modules/acs/_help.py

@@ -1791,6 +1791,18 @@
           text: az aks operation-abort -g myResourceGroup -n myAKSCluster
 """
 
+helps['aks nodepool delete-machines'] = """
+    type: command
+    short-summary: Delete specific machines in an agentpool for a managed cluster.
+    parameters:
+        - name: --machine-names
+          type: string array
+          short-summary: Space-separated list of machine names from the agent pool to be deleted.
+    examples:
+        - name: Delete specific machines in an agent pool
+          text: az aks nodepool delete-machines -g myResourceGroup --nodepool-name nodepool1 --cluster-name myAKSCluster --machine-names machine1
+"""
+
 helps['aks remove-dev-spaces'] = """
 type: command
 short-summary: Remove Azure Dev Spaces from a managed Kubernetes cluster.

src/azure-cli/azure/cli/command_modules/acs/_params.py

@@ -913,6 +913,14 @@ def load_arguments(self, _):
         c.argument('dns_zone_resource_ids', options_list=['--ids'], required=True)
         c.argument('attach_zones')
 
+    with self.argument_context("aks nodepool delete-machines") as c:
+        c.argument(
+            "machine_names",
+            nargs="+",
+            required=True,
+            help="Space-separated machine names to delete.",
+        )
+
 
 def _get_default_install_location(exe_name):
     system = platform.system()

src/azure-cli/azure/cli/command_modules/acs/commands.py

@@ -134,6 +134,7 @@ def load_command_table(self, _):
         g.custom_command('start', 'aks_agentpool_start', supports_no_wait=True)
         g.wait_command('wait')
         g.custom_command('operation-abort', 'aks_agentpool_operation_abort', supports_no_wait=True)
+        g.custom_command('delete-machines', 'aks_agentpool_delete_machines', supports_no_wait=True)
 
     with self.command_group('aks command', managed_clusters_sdk, client_factory=cf_managed_clusters) as g:
         g.custom_command('invoke', 'aks_runcommand', supports_no_wait=True,

src/azure-cli/azure/cli/command_modules/acs/custom.py

@@ -90,6 +90,7 @@
     ResourceNotFoundError,
     UnknownError,
     ValidationError,
+    RequiredArgumentMissingError,
 )
 from azure.cli.core.commands import LongRunningOperation
 from azure.cli.core.commands.client_factory import get_subscription_id
@@ -2648,6 +2649,49 @@ def aks_operation_abort(cmd,   # pylint: disable=unused-argument
     return sdk_no_wait(no_wait, client.begin_abort_latest_operation, resource_group_name, name)
 
 
+def aks_agentpool_delete_machines(cmd,   # pylint: disable=unused-argument
+                                  client,
+                                  resource_group_name,
+                                  cluster_name,
+                                  nodepool_name,
+                                  machine_names,
+                                  no_wait=False):
+    agentpool_exists = False
+    instances = client.list(resource_group_name, cluster_name)
+    for agentpool_profile in instances:
+        if agentpool_profile.name.lower() == nodepool_name.lower():
+            agentpool_exists = True
+            break
+
+    if not agentpool_exists:
+        raise ResourceNotFoundError(
+            f"Node pool {nodepool_name} doesn't exist, "
+            "use 'az aks nodepool list' to get current node pool list"
+        )
+
+    if len(machine_names) == 0:
+        raise RequiredArgumentMissingError(
+            "--machine-names doesn't provide, "
+            "use 'az aks machine list' to get current machine list"
+        )
+
+    AgentPoolDeleteMachinesParameter = cmd.get_models(
+        "AgentPoolDeleteMachinesParameter",
+        resource_type=ResourceType.MGMT_CONTAINERSERVICE,
+        operation_group="agent_pools",
+    )
+
+    machines = AgentPoolDeleteMachinesParameter(machine_names=machine_names)
+    return sdk_no_wait(
+        no_wait,
+        client.begin_delete_machines,
+        resource_group_name,
+        cluster_name,
+        nodepool_name,
+        machines,
+    )
+
+
 def aks_agentpool_show(cmd, client, resource_group_name, cluster_name, nodepool_name):
     instance = client.get(resource_group_name, cluster_name, nodepool_name)
     return instance

src/azure-cli/azure/cli/command_modules/acs/tests/latest/test_aks_commands.py

@@ -7923,6 +7923,91 @@ def test_aks_nodepool_snapshot(self, resource_group, resource_group_location):
             self.is_empty()
         ])
 
+    # live only, otherwise the current recording mechanism will also record the binary files of
+    # kubectl and kubelogin resulting in the cassette file
+    @live_only()
+    @AllowLargeResponse()
+    @AKSCustomResourceGroupPreparer(random_name_length=17, name_prefix="clitest", location="westus2")
+    def test_aks_nodepool_delete_machines(self, resource_group, resource_group_location):
+        aks_name = self.create_random_name("cliakstest", 16)
+        nodepool_name = self.create_random_name("c", 6)
+        self.kwargs.update(
+            {
+                "resource_group": resource_group,
+                "location": resource_group_location,
+                "name": aks_name,
+                "nodepool_name": nodepool_name,
+                "ssh_key_value": self.generate_ssh_keys(),
+            }
+        )
+
+        # create aks cluster
+        create_cmd = "aks create --resource-group={resource_group} --name={name} --ssh-key-value={ssh_key_value}"
+        self.cmd(
+            create_cmd,
+            checks=[
+                self.check("provisioningState", "Succeeded"),
+            ],
+        )
+        # add nodepool
+        self.cmd(
+            "aks nodepool add --resource-group={resource_group} --cluster-name={name} --name={nodepool_name} --node-count=4",
+            checks=[self.check("provisioningState", "Succeeded")],
+        )
+
+        # install kubectl
+        try:
+            subprocess.call(["az", "aks", "install-cli"])
+        except subprocess.CalledProcessError as err:
+            raise CLIInternalError("Failed to install kubectl with error: '{}'!".format(err))
+
+        try:
+            # get credential
+            fd, browse_path = tempfile.mkstemp()
+            self.kwargs.update(
+                {
+                    "browse_path": browse_path,
+                }
+            )
+            try:
+                get_credential_cmd = "aks get-credentials -n {name} -g {resource_group} -f {browse_path}"
+                self.cmd(get_credential_cmd)
+            finally:
+                os.close(fd)
+
+            # get machine name
+            label = "kubernetes.azure.com/agentpool=" + nodepool_name
+            k_get_node_cmd = ["kubectl", "get", "node", "-l", label, "-o", "name", "--kubeconfig", browse_path]
+            k_get_node_output = subprocess.check_output(
+                k_get_node_cmd,
+                universal_newlines=True,
+                stderr=subprocess.STDOUT,
+            )
+            machine_names = k_get_node_output.split("\n")
+
+            machine_name = machine_names[0].strip().strip("node/").strip()
+            print(f"machine_name: {machine_name}")
+            self.kwargs.update(
+                {
+                    "machine_name": machine_name,
+                }
+            )
+
+            # delete machines
+            self.cmd(
+                "aks nodepool delete-machines --resource-group={resource_group} --cluster-name={name} --nodepool-name={nodepool_name} --machine-names={machine_name}"
+            )
+
+            # check count
+            self.cmd('aks show -g {resource_group} -n {name}', checks=[
+                self.check('agentPoolProfiles[1].count', 3)
+            ])
+
+        finally:
+            # delete cluster
+            self.cmd(
+                'aks delete -g {resource_group} -n {name} --yes --no-wait', checks=[self.is_empty()])
+
     @AllowLargeResponse()
     @AKSCustomResourceGroupPreparer(random_name_length=17, name_prefix='clitest', location='centraluseuap')
     def test_aks_create_with_windows_gmsa(self, resource_group, resource_group_location):