feat: Enhance DHCP release process with dhclient check and logging

mfd_network_adapter/network_interface/feature/ip/linux.py

@@ -189,17 +189,21 @@ def release_ip(self, ip_version: IPVersion) -> None:
 
         :param ip_version: IP version to use
         """
-        # release current lease
-        cmd = f"dhclient -r {self._interface().name}"
-        output = self._connection.execute_command(cmd, expected_return_codes={})
-        if output.return_code and "dhcpcd not running" not in output.stdout:
-            raise IPFeatureException(
-                f"Unknown error msg returned, while releasing IP on {self._interface().name} - {output.stderr}"
-            )
+        dhclient_output = self._connection.execute_command("command -v dhclient", expected_return_codes={0, 1})
+        if dhclient_output.return_code == 0:
+            # release current lease
+            cmd = f"dhclient -r {self._interface().name}"
+            output = self._connection.execute_command(cmd, expected_return_codes={})
+            if output.return_code and "dhcpcd not running" not in output.stdout.casefold():
+                raise IPFeatureException(
+                    f"Unknown error msg returned, while releasing IP on {self._interface().name} - {output.stderr}"
+                )
+        else:
+            logger.log(level=log_levels.MODULE_DEBUG, msg="dhclient not found, skipping DHCP release step.")
 
         # RHEL7 still keeps IP after releasing it, so we need to remove it
         cmd = f"ip -{ip_version.value} addr flush dev {self._interface().name}"
-        self._connection.execute_command(cmd)
+        self._connection.execute_command(add_namespace_call_command(cmd, namespace=self._interface().namespace))
 
     def renew_ip(self) -> None:
         """Refresh Ip address."""

tests/unit/test_mfd_network_adapter/test_network_interface/test_feature/test_ip/test_ip_linux.py

@@ -183,6 +183,22 @@ def test_release_ip(self, interface):
             ]
         )
 
+    def test_release_ip_dhclient_not_found(self, interface):
+        interface._connection.execute_command.side_effect = [
+            ConnectionCompletedProcess(return_code=1, args="", stdout="", stderr=""),
+            ConnectionCompletedProcess(return_code=0, args="", stdout="", stderr=""),
+        ]
+        interface.ip.release_ip(IPVersion.V4)
+        interface._connection.execute_command.assert_called_with(f"ip -4 addr flush dev {interface.name}")
+
+    def test_release_ip_raises_on_dhclient_error(self, interface):
+        interface._connection.execute_command.side_effect = [
+            ConnectionCompletedProcess(return_code=0, args="", stdout="", stderr=""),
+            ConnectionCompletedProcess(return_code=1, args="", stdout="some error", stderr="some error"),
+        ]
+        with pytest.raises(IPFeatureException):
+            interface.ip.release_ip(IPVersion.V4)
+
     def test_renew_ip(self, interface):
         interface._connection.execute_command.return_value = ConnectionCompletedProcess(
             return_code=0, args="", stdout="", stderr=""