feat: add motd to GA CLI

Author: Mikolaj Umanski

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

@@ -265,6 +265,9 @@
     type: string
     short-summary: A CIDR notation IP range from which to assign pod IPs when kubenet is used.
     long-summary: This range must not overlap with any Subnet IP ranges. For example, 172.244.0.0/16.
+  - name: --message-of-the-day
+    type: string
+    short-summary: Path to a file containing the desired message of the day. Only valid for linux nodes. Will be written to /etc/motd.
   - name: --service-cidr
     type: string
     short-summary: A CIDR notation IP range from which to assign service cluster IPs.
@@ -1608,6 +1611,9 @@
   - name: --linux-os-config
     type: string
     short-summary: Path to JSON file containing OS configurations for Linux agent nodes. https://aka.ms/aks/custom-node-config
+  - name: --message-of-the-day
+    type: string
+    short-summary: Path to a file containing the desired message of the day. Only valid for linux nodes. Will be written to /etc/motd.
   - name: --host-group-id
     type: string
     short-summary: The fully qualified dedicated host group id used to provision agent node pool.

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

@@ -99,7 +99,8 @@
     validate_node_public_ip_tags,
     validate_disable_windows_outbound_nat,
     validate_crg_id,
-    validate_azure_service_mesh_revision)
+    validate_azure_service_mesh_revision,
+    validate_message_of_the_day)
 from azure.cli.core.commands.parameters import (
     edge_zone_type, file_type, get_enum_type,
     get_resource_name_completion_list, get_three_state_flag, name_type,
@@ -424,6 +425,8 @@ def load_arguments(self, _):
         c.argument('gpu_instance_profile', arg_type=get_enum_type(gpu_instance_profiles))
         c.argument('nodepool_allowed_host_ports', nargs='+', validator=validate_allowed_host_ports, help="allowed host ports for agentpool")
         c.argument('nodepool_asg_ids', nargs='+', validator=validate_application_security_groups, help="application security groups for agentpool")
+        c.argument("message_of_the_day")
+
         # azure monitor profile
         c.argument('enable_azure_monitor_metrics', action='store_true')
         c.argument('azure_monitor_workspace_resource_id', validator=validate_azuremonitorworkspaceresourceid)
@@ -791,6 +794,7 @@ def load_arguments(self, _):
         c.argument('asg_ids', nargs='+', validator=validate_application_security_groups)
         c.argument('node_public_ip_tags', arg_type=tags_type, validator=validate_node_public_ip_tags,
                    help='space-separated tags: key[=value] [key[=value] ...].')
+        c.argument("message_of_the_day", validator=validate_message_of_the_day)
         c.argument('enable_vtpm', action='store_true')
         c.argument('enable_secure_boot', action='store_true')
         c.argument("if_match")

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

@@ -827,3 +827,10 @@ def validate_disable_windows_outbound_nat(namespace):
         if hasattr(namespace, 'os_type') and str(namespace.os_type).lower() != "windows":
             raise ArgumentUsageError(
                 '--disable-windows-outbound-nat can only be set for Windows nodepools')
+
+def validate_message_of_the_day(namespace):
+    """Validates message of the day can only be used on Linux."""
+    if namespace.message_of_the_day is not None and namespace.message_of_the_day != "":
+        if namespace.os_type is not None and namespace.os_type != "Linux":
+            raise ArgumentUsageError(
+                '--message-of-the-day can only be set for linux nodepools')

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

@@ -4,6 +4,7 @@
 # --------------------------------------------------------------------------------------------
 
 import os
+import base64
 from math import isnan
 from types import SimpleNamespace
 from typing import Dict, List, Tuple, TypeVar, Union
@@ -41,7 +42,7 @@
 from azure.cli.core.cloud import get_active_cloud
 from azure.cli.core.commands import AzCliCommand
 from azure.cli.core.profiles import ResourceType
-from azure.cli.core.util import get_file_json, sdk_no_wait
+from azure.cli.core.util import get_file_json, sdk_no_wait, read_file_content
 from knack.log import get_logger
 
 logger = get_logger(__name__)
@@ -390,6 +391,33 @@ def _get_crg_id(self) -> Union[str, None]:
             crg_id = raw_value
         return crg_id
 
+    def get_message_of_the_day(self) -> Union[str, None]:
+        """Obtain the value of message_of_the_day.
+
+        :return: string or None
+        """
+        # read the original value passed by the command
+        message_of_the_day = None
+        message_of_the_day_file_path = self.raw_param.get("message_of_the_day")
+
+        if message_of_the_day_file_path:
+            if not os.path.isfile(message_of_the_day_file_path):
+                raise InvalidArgumentValueError(
+                    f"{message_of_the_day_file_path} is not valid file, or not accessible."
+                )
+            message_of_the_day = read_file_content(
+                message_of_the_day_file_path)
+            message_of_the_day = base64.b64encode(
+                bytes(message_of_the_day, 'ascii')).decode('ascii')
+
+        # try to read the property value corresponding to the parameter from the `mc` object
+        if self.agentpool and self.agentpool.message_of_the_day is not None:
+            message_of_the_day = self.agentpool.message_of_the_day
+
+        # this parameter does not need dynamic completion
+        # this parameter does not need validation
+        return message_of_the_day
+
     def get_enable_vtpm(self) -> bool:
         return self._get_enable_vtpm(enable_validation=True)
 
@@ -1797,6 +1825,16 @@ def set_up_custom_node_config(self, agentpool: AgentPool) -> AgentPool:
         agentpool.linux_os_config = self.context.get_linux_os_config()
         return agentpool
 
+    def set_up_motd(self, agentpool: AgentPool) -> AgentPool:
+        """Set up message of the day for the AgentPool object.
+
+        :return: the AgentPool object
+        """
+        self._ensure_agentpool(agentpool)
+
+        agentpool.message_of_the_day = self.context.get_message_of_the_day()
+        return agentpool
+
     def set_up_gpu_properties(self, agentpool: AgentPool) -> AgentPool:
         """Set up gpu related properties for the AgentPool object.
 

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

@@ -629,6 +629,7 @@ def aks_create(
     host_group_id=None,
     crg_id=None,
     gpu_instance_profile=None,
+    message_of_the_day=None,
     # azure service mesh
     enable_azure_service_mesh=None,
     revision=None,
@@ -2385,6 +2386,7 @@ def aks_agentpool_add(
     labels=None,
     tags=None,
     node_taints=None,
+    message_of_the_day=None,
     node_osdisk_type=None,
     node_osdisk_size=None,
     max_surge=None,

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

@@ -1314,6 +1314,39 @@ def common_get_scale_down_mode(self):
         ctx_2.attach_agentpool(agentpool_2)
         self.assertEqual(ctx_2.get_scale_down_mode(), "test_scale_down_mode")
 
+    def common_get_message_of_the_day(self):
+        # default
+        ctx_1 = AKSAgentPoolContext(
+            self.cmd,
+            AKSAgentPoolParamDict({"message_of_the_day": None}),
+            self.models,
+            DecoratorMode.CREATE,
+            self.agentpool_decorator_mode,
+        )
+        self.assertEqual(ctx_1.get_message_of_the_day(), None)
+        agent_pool_profile = self.models.ManagedClusterAgentPoolProfile(
+            name="test_nodepool_name",
+            message_of_the_day="test_mc_message_of_the_day",
+        )
+        # mc = self.models.ManagedCluster(
+        #     location="test_location", agent_pool_profiles=[agent_pool_profile]
+        # )
+        ctx_1.attach_agentpool(agent_pool_profile)
+        self.assertEqual(
+            ctx_1.get_message_of_the_day(), "test_mc_message_of_the_day"
+        )
+
+        ctx_2 = AKSAgentPoolContext(
+            self.cmd,
+            AKSAgentPoolParamDict({"message_of_the_day": "fake-path"}),
+            self.models,
+            DecoratorMode.CREATE,
+            self.agentpool_decorator_mode,
+        )
+        # fail on invalid file path
+        with self.assertRaises(InvalidArgumentValueError):
+            ctx_2.get_message_of_the_day()
+
     def common_get_kubelet_config(self):
         # default
         ctx_1 = AKSAgentPoolContext(
@@ -1718,6 +1751,9 @@ def test_get_mode(self):
     def test_get_scale_down_mode(self):
         self.common_get_scale_down_mode()
 
+    def test_get_message_of_the_day(self):
+        self.common_get_message_of_the_day()
+
     def test_get_kubelet_config(self):
         self.common_get_kubelet_config()
 
@@ -1893,6 +1929,9 @@ def test_get_mode(self):
     def test_get_scale_down_mode(self):
         self.common_get_scale_down_mode()
 
+    def test_get_message_of_the_day(self):
+        self.common_get_message_of_the_day()
+
     def test_get_kubelet_config(self):
         self.common_get_kubelet_config()
 

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

@@ -164,6 +164,40 @@ def test_throws_on_negative(self):
         self.assertTrue('positive' in str(cm.exception), msg=str(cm.exception))
 
 
+class MessageOfTheDayNamespace:
+    def __init__(self, message_of_the_day, os_type):
+        self.os_type = os_type
+        self.message_of_the_day = message_of_the_day
+        
+class TestMessageOfTheday(unittest.TestCase):
+    def test_valid_cases(self):
+        valid = ["foo", ""]
+        for v in valid:
+            validators.validate_message_of_the_day(MessageOfTheDayNamespace(v, "Linux"))
+
+    def test_fail_if_os_type_windows(self):
+        with self.assertRaises(CLIError) as cm:
+            validators.validate_message_of_the_day(
+                MessageOfTheDayNamespace("foo", "Windows")
+            )
+        self.assertTrue(
+            "--message-of-the-day can only be set for linux nodepools"
+            in str(cm.exception),
+            msg=str(cm.exception),
+        )
+
+    def test_fail_if_os_type_invalid(self):
+        with self.assertRaises(CLIError) as cm:
+            validators.validate_message_of_the_day(
+                MessageOfTheDayNamespace("foo", "invalid")
+            )
+        self.assertTrue(
+            "--message-of-the-day can only be set for linux nodepools"
+            in str(cm.exception),
+            msg=str(cm.exception),
+        )
+
+
 class TestLabels(unittest.TestCase):
     def test_invalid_labels_prefix(self):
         invalid_labels = "k8s##.io/label1=value"