From 4ff31ec89ee86bbcda406a630a529bcbc9f0ceca Mon Sep 17 00:00:00 2001
From: "Nana@Nvidia" <78413612+nhe-NV@users.noreply.github.com>
Date: Sat, 17 Feb 2024 06:25:38 +0800
Subject: [PATCH] Update the static dns test case (#11652)

When do the dhclient, if not specify the management port, it will also do dhclient other port,and may cause some error msg. To avoid this, need to specify the management port when do the dhclient, and kill the deamon after the test finish.
---
 tests/dns/static_dns/test_static_dns.py | 31 +++++++++++++++++++------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/tests/dns/static_dns/test_static_dns.py b/tests/dns/static_dns/test_static_dns.py
index b68e2de084c..cd83fdad99b 100644
--- a/tests/dns/static_dns/test_static_dns.py
+++ b/tests/dns/static_dns/test_static_dns.py
@@ -2,6 +2,7 @@
 import logging
 import random
 import re
+import os
 
 from tests.common.reboot import reboot
 from tests.common.config_reload import config_reload
@@ -40,6 +41,22 @@
 EXCEED_MAX_ERR = r"Error: The maximum number \(3\) of nameservers exceeded"
 DUPLICATED_IP_ERR = r"Error: .* nameserver is already configured"
 
+MGMT_PORT = "eth0"
+DHCLIENT_PID_FILE = "/tmp/dhclient-dns-test.pid"
+
+
+def start_dhclient(duthost):
+    duthost.shell(f"sudo dhclient -pf {DHCLIENT_PID_FILE} {MGMT_PORT}")
+
+
+@pytest.fixture()
+def stop_dhclient(duthost):
+    yield
+
+    if os.path.exists(DHCLIENT_PID_FILE):
+        duthost.shell(f"sudo kill $(cat {DHCLIENT_PID_FILE})")
+        duthost.shell(f"rm -rf {DHCLIENT_PID_FILE}")
+
 
 @pytest.mark.disable_loganalyzer
 def test_static_dns_basic(request, duthost, localhost, mgmt_interfaces):
@@ -97,13 +114,13 @@ def test_static_dns_basic(request, duthost, localhost, mgmt_interfaces):
             if mgmt_interfaces:
                 verify_nameserver_in_conf_file(duthost, [])
             else:
-                origin_dynamic_nameservers = get_nameserver_from_resolvconf(duthost, file_name=RESOLV_CONF_FILE+".bk")
+                origin_dynamic_nameservers = get_nameserver_from_resolvconf(duthost, file_name=RESOLV_CONF_FILE + ".bk")
                 verify_nameserver_in_conf_file(duthost, origin_dynamic_nameservers)
 
 
 @pytest.mark.usefixtures('static_mgmt_ip_configured')
 class TestStaticMgmtPortIP():
-    def test_dynamic_dns_not_working_when_static_ip_configured(self, duthost):
+    def test_dynamic_dns_not_working_when_static_ip_configured(self, duthost, stop_dhclient):
         """
         Test to verify Dynamic DNS not work when static ip address is configured on the mgmt port
         :param duthost: DUT host object
@@ -120,13 +137,13 @@ def test_dynamic_dns_not_working_when_static_ip_configured(self, duthost):
             verify_nameserver_in_conf_file(duthost, [])
 
         with allure.step("Renew dhcp to restore the dns configuration."):
-            duthost.shell("sudo dhclient")
+            start_dhclient(duthost)
             verify_nameserver_in_conf_file(duthost, [])
 
 
 @pytest.mark.usefixtures('static_mgmt_ip_not_configured')
 class TestDynamicMgmtPortIP():
-    def test_static_dns_is_not_changing_when_do_dhcp_renew(self, duthost):
+    def test_static_dns_is_not_changing_when_do_dhcp_renew(self, duthost, stop_dhclient):
         """
         Test case to verify Static DNS will not change when do dhcp renew for the mgmt port
         :param duthost: DUT host object
@@ -143,7 +160,7 @@ def test_static_dns_is_not_changing_when_do_dhcp_renew(self, duthost):
                 verify_nameserver_in_conf_file(duthost, expected_nameservers)
 
         with allure.step("Renew dhcp to restore the dns configuration."):
-            duthost.shell("sudo dhclient")
+            start_dhclient(duthost)
 
         with allure.step(f"Verify that {RESOLV_CONF_FILE} is not modified"):
             verify_nameserver_in_conf_file(duthost, expected_nameservers)
@@ -153,7 +170,7 @@ def test_static_dns_is_not_changing_when_do_dhcp_renew(self, duthost):
                 del_dns_nameserver(duthost, nameserver)
 
     @pytest.mark.usefixtures('static_mgmt_ip_not_configured')
-    def test_dynamic_dns_working_when_no_static_ip_and_static_dns(self, duthost):
+    def test_dynamic_dns_working_when_no_static_ip_and_static_dns(self, duthost, stop_dhclient):
         """
         The test is to verify Dynamic DNS work as expected when no static ip configured on mgmt port and
         static DNS is configured.
@@ -182,7 +199,7 @@ def test_dynamic_dns_working_when_no_static_ip_and_static_dns(self, duthost):
             config_mgmt_ip(duthost, mgmt_interfaces, "remove")
 
         with allure.step("Renew dhcp to restore the dns configuration."):
-            duthost.shell("sudo dhclient")
+            start_dhclient(duthost)
             verify_nameserver_in_conf_file(duthost, origin_dynamic_nameservers)