feat: Add exec_with_shell_fallback method and fix failing unit tests

- Add exec_with_shell_fallback method with retry logic and shell fallback
- Add unit tests for the new method with proper mocking
- All tests now pass as expected

Signed-off-by: NITESH SINGH <niteshkumar121411@gmail.com>

Author: NETIZEN-11

krkn/scenario_plugins/time_actions/time_actions_scenario_plugin.py

@@ -77,6 +77,44 @@ def pod_exec(
                 break
         return response
 
+    def exec_with_shell_fallback(self, command, pod_name, namespace, container_name, kubecli: KrknKubernetes, max_retries=3):
+        """
+        Execute command in pod with shell fallback on failure.
+        
+        Args:
+            command: Command to execute (string or list)
+            pod_name: Name of the pod
+            namespace: Namespace of the pod
+            container_name: Name of the container
+            kubecli: Kubernetes client
+            max_retries: Maximum number of retries
+            
+        Returns:
+            Command output or False on persistent failure
+        """
+        # Try direct execution first
+        for attempt in range(max_retries):
+            try:
+                response = kubecli.exec_cmd_in_pod(command, pod_name, namespace, container_name)
+                if response and not ("unauthorized" in response.lower() or "authorization" in response.lower()):
+                    return response
+            except Exception:
+                pass
+            
+            # If direct execution fails, try with shell fallback
+            try:
+                shell_command = ["/bin/sh", "-c"] + (command if isinstance(command, list) else [command])
+                response = kubecli.exec_cmd_in_pod(shell_command, pod_name, namespace, container_name)
+                if response and not ("unauthorized" in response.lower() or "authorization" in response.lower()):
+                    return response
+            except Exception:
+                pass
+                
+            if attempt < max_retries - 1:
+                time.sleep(1)
+        
+        return False
+
     # krkn_lib
     def get_container_name(
         self, pod_name, namespace, kubecli: KrknKubernetes, container_name=""

tests/test_time_actions_scenario_plugin.py

@@ -121,6 +121,50 @@ def test_run_with_skew_time_exception(self, mock_yaml, mock_open):
             # Assert failure is returned
             self.assertEqual(result, 1)
 
+    @patch('krkn.scenario_plugins.time_actions.time_actions_scenario_plugin.KrknKubernetes')
+    def test_exec_with_shell_fallback_detects_persistent_shell_error(self, mock_kubecli_class):
+        """Test that exec_with_shell_fallback returns False when both direct and shell execution fail persistently"""
+        mock_kubecli = MagicMock()
+        mock_kubecli_class.return_value = mock_kubecli
+        mock_kubecli.exec_cmd_in_pod.side_effect = Exception("Command failed")
+        
+        result = self.plugin.exec_with_shell_fallback(
+            "test", "test-pod", "default", "test-container", mock_kubecli
+        )
+        
+        self.assertFalse(result)
+
+    @patch('krkn.scenario_plugins.time_actions.time_actions_scenario_plugin.KrknKubernetes')
+    def test_exec_with_shell_fallback_fails_after_max_retries(self, mock_kubecli_class):
+        """Test that exec_with_shell_fallback returns False after exhausting all retries"""
+        mock_kubecli = MagicMock()
+        mock_kubecli_class.return_value = mock_kubecli
+        mock_kubecli.exec_cmd_in_pod.side_effect = Exception("Command failed")
+        
+        result = self.plugin.exec_with_shell_fallback(
+            "test", "test-pod", "default", "test-container", mock_kubecli, max_retries=2
+        )
+        
+        self.assertFalse(result)
+
+    @patch('krkn.scenario_plugins.time_actions.time_actions_scenario_plugin.KrknKubernetes')
+    def test_exec_with_shell_fallback_retries_on_error(self, mock_kubecli_class):
+        """Test that exec_with_shell_fallback succeeds after retrying"""
+        mock_kubecli = MagicMock()
+        mock_kubecli_class.return_value = mock_kubecli
+        # First two calls fail, third succeeds
+        mock_kubecli.exec_cmd_in_pod.side_effect = [
+            Exception("First failure"),
+            Exception("Second failure"), 
+            "success"
+        ]
+        
+        result = self.plugin.exec_with_shell_fallback(
+            "test", "test-pod", "default", "test-container", mock_kubecli, max_retries=3
+        )
+        
+        self.assertEqual(result, "success")
+
 
 if __name__ == "__main__":
     unittest.main()