feat(anta): Added the test case to verify the Graceful Restart (GR) and GR-Helper

anta/input_models/routing/isis.py

@@ -0,0 +1,32 @@
+# Copyright (c) 2023-2025 Arista Networks, Inc.
+# Use of this source code is governed by the Apache License 2.0
+# that can be found in the LICENSE file.
+"""Module containing input models for ISIS tests."""
+
+from __future__ import annotations
+
+from pydantic import BaseModel, ConfigDict
+
+
+class ISISInstances(BaseModel):
+    """Model for a list of ISIS instance entries."""
+
+    model_config = ConfigDict(extra="forbid")
+    name: str
+    """The instance name to validated the instance specific isis details."""
+    vrf: str = "default"
+    """VRF context. Defaults to `default` VRF."""
+    graceful_restart: bool = True
+    """Specifies the Graceful Restart,
+    Options:
+    - True: Default mode, refer as graceful restart is enabled.
+    - False: Refer as graceful restart is disabled."""
+    graceful_helper: bool = True
+    """Specifies the Graceful Restart Helper,
+    Options:
+    - True: Default mode, refer as graceful restart helper is enabled.
+    - False: Refer as graceful restart helper is disabled."""
+
+    def __str__(self) -> str:
+        """Return a human-readable string representation of the ISISInstances for reporting."""
+        return f"Instance: {self.name} VRF: {self.vrf}"

anta/tests/routing/isis.py

@@ -13,6 +13,7 @@
 from pydantic import BaseModel
 
 from anta.custom_types import Interface
+from anta.input_models.routing.isis import ISISInstances
 from anta.models import AntaCommand, AntaTemplate, AntaTest
 from anta.tools import get_value
 
@@ -728,3 +729,89 @@ def _check_tunnel_id(self, via_input: VerifyISISSegmentRoutingTunnels.Input.Entr
                 for eos_via in eos_entry["vias"]
             )
         return True
+
+
+class VerifyISISGracefulRestart(AntaTest):
+    """Verifies the graceful restart and helper mechanism.
+
+    This test performs the following checks:
+
+     1. Verifies that the ISIS is configured.
+     2. Verifies that the specified ISIS instance is found on the device.
+     4. Verifies that the expected and actual IS-IS graceful restart and graceful helper values are matched.
+
+    Expected Results
+    ----------------
+    * Success: The test will pass if all of the following conditions are met:
+        - The ISIS is configured on the device.
+        - The specified ISIS instance is exist on the device.
+        - Expected and actual IS-IS graceful restart and graceful helper values are matched.
+    * Failure: The test will fail if any of the following conditions is met:
+        - The ISIS is not configured on the device.
+        - The Specified ISIS instance do not exist on the device.
+        - Expected and actual IS-IS graceful restart and graceful helper values are not matched.
+
+    Examples
+    --------
+    ```yaml
+    anta.tests.routing:
+      isis:
+        - VerifyISISGracefulRestart:
+            instances:
+              - name: '1'
+                vrf: default
+                graceful_restart: True
+                graceful_helper: True
+              - name: '2'
+                vrf: default
+                graceful_restart: True
+                graceful_helper: True
+              - name: '1'
+                vrf: test
+                graceful_restart: True
+                graceful_helper: True
+              - name: '2'
+                vrf: test
+                graceful_restart: True
+                graceful_helper: True
+    ```
+    """
+
+    categories: ClassVar[list[str]] = ["isis"]
+    commands: ClassVar[list[AntaCommand | AntaTemplate]] = [AntaCommand(command="show isis summary vrf all", revision=2)]
+
+    class Input(AntaTest.Input):
+        """Input model for the VerifyISISGracefulRestart test."""
+
+        instances: list[ISISInstances]
+        """List of IS-IS instance entries."""
+
+    @AntaTest.anta_test
+    def test(self) -> None:
+        """Main test function for VerifyISISGracefulRestart."""
+        self.result.is_success()
+        command_output = self.instance_commands[0].json_output
+        isis_details = command_output.get("vrfs")
+
+        # If IS-IS is not configured, test fails.
+        if not isis_details:
+            self.result.is_failure("ISIS is not configured")
+            return
+
+        # If IS-IS instance is not found or GR and GR helpers are not matching with the expected values, test fails.
+        for instance in self.inputs.instances:
+            vrf = instance.vrf
+            instance_name = str(instance.name)
+            graceful_restart = instance.graceful_restart
+            graceful_helper = instance.graceful_helper
+
+            if (instance_details := get_value(isis_details, f"{vrf}.isisInstances.{instance_name}")) is None:
+                self.result.is_failure(f"{instance} - Not found")
+                continue
+
+            if instance_details.get("gracefulRestart") != graceful_restart:
+                self.result.is_failure(f"{instance} - Graceful Restart disabled")
+
+            actual_gr_helper = instance_details.get("gracefulRestartHelper")
+            if actual_gr_helper != graceful_helper:
+                self.result.is_failure(f"{instance} - Graceful Restart Helper disabled")

docs/api/tests.routing.isis.md

@@ -7,6 +7,8 @@ anta_title: ANTA catalog for IS-IS tests
   ~ that can be found in the LICENSE file.
   -->
 
+# Test
+
 ::: anta.tests.routing.isis
 
     options:
@@ -20,3 +22,16 @@ anta_title: ANTA catalog for IS-IS tests
         - "!test"
         - "!render"
         - "!^_[^_]"
+
+# Input models
+
+::: anta.input_models.routing.isis
+
+    options:
+      show_root_heading: false
+      show_root_toc_entry: false
+      show_bases: false
+      merge_init_into_class: false
+      anta_hide_test_module_description: true
+      show_labels: true
+      filters: ["!^__str__"]

examples/tests.yaml

@@ -541,6 +541,25 @@ anta.tests.routing.generic:
       minimum: 2
       maximum: 20
 anta.tests.routing.isis:
+  - VerifyISISGracefulRestart:
+      # Verifies the graceful restart and helper mechanism.
+      instances:
+        - name: '1'
+          vrf: default
+          graceful_restart: True
+          graceful_helper: True
+        - name: '2'
+          vrf: default
+          graceful_restart: True
+          graceful_helper: True
+        - name: '1'
+          vrf: test
+          graceful_restart: True
+          graceful_helper: True
+        - name: '2'
+          vrf: test
+          graceful_restart: True
+          graceful_helper: True
   - VerifyISISInterfaceMode:
       # Verifies interface mode for IS-IS
       interfaces:

tests/units/anta_tests/routing/test_isis.py

@@ -12,6 +12,7 @@
 import pytest
 
 from anta.tests.routing.isis import (
+    VerifyISISGracefulRestart,
     VerifyISISInterfaceMode,
     VerifyISISNeighborCount,
     VerifyISISNeighborState,
@@ -1840,6 +1841,107 @@
             "messages": ["Tunnel to 1.0.0.111/32 is incorrect: incorrect tunnel ID"],
         },
     },
+    {
+        "name": "success",
+        "test": VerifyISISGracefulRestart,
+        "eos_data": [
+            {
+                "vrfs": {
+                    "default": {
+                        "isisInstances": {
+                            "1": {"gracefulRestart": True, "gracefulRestartHelper": True},
+                            "2": {"gracefulRestart": True, "gracefulRestartHelper": True},
+                        }
+                    },
+                    "test": {
+                        "isisInstances": {
+                            "1": {"gracefulRestart": True, "gracefulRestartHelper": True},
+                            "2": {"gracefulRestart": True, "gracefulRestartHelper": True},
+                        }
+                    },
+                }
+            }
+        ],
+        "inputs": {
+            "instances": [
+                {"vrf": "default", "name": "1", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "default", "name": "2", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "test", "name": "1", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "test", "name": "2", "graceful_restart": True, "graceful_helper": True},
+            ]
+        },
+        "expected": {"result": "success"},
+    },
+    {
+        "name": "failure-isis-not-configured",
+        "test": VerifyISISGracefulRestart,
+        "eos_data": [{"vrfs": {}}],
+        "inputs": {"instances": [{"vrf": "default", "name": "1", "graceful_restart": True, "graceful_helper": True}]},
+        "expected": {"result": "failure", "messages": ["ISIS is not configured"]},
+    },
+    {
+        "name": "failure-isis-instance-not-found",
+        "test": VerifyISISGracefulRestart,
+        "eos_data": [{"vrfs": {"default": {"isisInstances": {"2": {"gracefulRestart": True, "gracefulRestartHelper": True}}}}}],
+        "inputs": {"instances": [{"vrf": "default", "name": "1", "graceful_restart": True, "graceful_helper": True}]},
+        "expected": {"result": "failure", "messages": ["Instance: 1 VRF: default - Not found"]},
+    },
+    {
+        "name": "failure-graceful-restart-disabled",
+        "test": VerifyISISGracefulRestart,
+        "eos_data": [
+            {
+                "vrfs": {
+                    "default": {
+                        "isisInstances": {
+                            "1": {"gracefulRestart": False, "gracefulRestartHelper": True},
+                            "2": {"gracefulRestart": True, "gracefulRestartHelper": True},
+                        }
+                    },
+                    "test": {
+                        "isisInstances": {
+                            "1": {"gracefulRestart": False, "gracefulRestartHelper": True},
+                            "2": {"gracefulRestart": True, "gracefulRestartHelper": True},
+                        }
+                    },
+                }
+            }
+        ],
+        "inputs": {
+            "instances": [
+                {"vrf": "default", "name": "1", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "default", "name": "2", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "test", "name": "1", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "test", "name": "2", "graceful_restart": True, "graceful_helper": True},
+            ]
+        },
+        "expected": {
+            "result": "failure",
+            "messages": ["Instance: 1 VRF: default - Graceful Restart disabled", "Instance: 1 VRF: test - Graceful Restart disabled"],
+        },
+    },
+    {
+        "name": "failure-graceful-restart-helper-disabled",
+        "test": VerifyISISGracefulRestart,
+        "eos_data": [
+            {
+                "vrfs": {
+                    "default": {"isisInstances": {"1": {"gracefulRestart": True, "gracefulRestartHelper": False}}},
+                    "test": {"isisInstances": {"1": {"gracefulRestart": True, "gracefulRestartHelper": False}}},
+                }
+            }
+        ],
+        "inputs": {
+            "instances": [
+                {"vrf": "default", "name": "1", "graceful_restart": True, "graceful_helper": True},
+                {"vrf": "test", "name": "1", "graceful_restart": True, "graceful_helper": True},
+            ]
+        },
+        "expected": {
+            "result": "failure",
+            "messages": ["Instance: 1 VRF: default - Graceful Restart Helper disabled", "Instance: 1 VRF: test - Graceful Restart Helper disabled"],
+        },
+    },
 ]