Update script test_syslog_source_ip (sonic-net#11253)

Add a vrf create status check function
To make the script more stable

Change-Id: I4925ad1c136419170751f1ec967c38205aa47142

Author: echuawu

tests/syslog/syslog_utils.py

@@ -58,6 +58,18 @@ def create_vrf(dut, vrf):
     dut.command('sudo config vrf add {} '.format(vrf), module_async=True)
 
 
+def check_vrf(dut, vrf):
+    """
+    Check if Vrf was created
+
+    Args:
+        dut (SonicHost): The target device
+        vrf (str): vrf
+    """
+    res = dut.command('sudo show vrf')["stdout"]
+    return vrf in res
+
+
 def remove_vrf(dut, vrf):
     """
     Remove Vrf

tests/syslog/test_syslog_source_ip.py

@@ -7,7 +7,7 @@
 
 from scapy.all import rdpcap
 from .syslog_utils import create_vrf, remove_vrf, add_syslog_server, del_syslog_server, capture_syslog_packets,\
-    replace_ip_neigh, is_mgmt_vrf_enabled, bind_interface_to_vrf, TCPDUMP_CAPTURE_TIME, DUT_PCAP_FILEPATH
+    replace_ip_neigh, is_mgmt_vrf_enabled, bind_interface_to_vrf, check_vrf, TCPDUMP_CAPTURE_TIME, DUT_PCAP_FILEPATH
 from tests.common.utilities import wait_until
 from tests.common.helpers.assertions import pytest_assert
 from tests.common.reboot import reboot, SONIC_SSH_PORT, SONIC_SSH_REGEX
@@ -220,6 +220,9 @@ def configure_data_vrf_test_data(self, routed_interfaces):
         logger.info("Create data vrf {}".format(VRF_LIST[1]))
         create_vrf(self.duthost, VRF_LIST[1])
 
+        logger.info(f"Validate vrf {VRF_LIST[1]} is created")
+        wait_until(5, 1, 0, check_vrf, self.duthost, VRF_LIST[1])
+
         logger.info("Bind interface {} to  data vrf {}".format(routed_interfaces[1], VRF_LIST[1]))
         bind_interface_to_vrf(self.asichost, VRF_LIST[1], routed_interfaces[1])