Add IPv6-only test case for NTP (sonic-net#12258)

## Type of change

- [x] Test case(new/improvement)

## Approach
#### What is the motivation for this PR?

Add support for testing NTP over IPv6. Additionally, test NTP when running with an IPv6-only network.

Also, this fixes the IPv6 address assignment for vlab-02 and makes sure it's given an address on the same subnet as the PTF container.

### How did you verify/test it?

Tested on KVM and physical DUT with IPv6-only mgmt address.

ansible/lab

@@ -121,6 +121,7 @@ sonic_s6100:
       ansible_host: 10.251.0.190
     vlab-02:
       ansible_host: 10.250.0.114
+      ansible_hostv6: fec0::ffff:afa:e
 
 sonic_a7260:
   vars:

ansible/veos_vtb

@@ -111,7 +111,7 @@ all:
           ansible_user: admin
         vlab-02:
           ansible_host: 10.250.0.114
-          ansible_hostv6: fec0::ffff:afa:2
+          ansible_hostv6: fec0::ffff:afa:e
           type: kvm
           hwsku: Force10-S6100
           serial_port: 9095

tests/common/devices/base.py

@@ -44,6 +44,10 @@ def __init__(self, ansible_adhoc, hostname, *args, **kwargs):
         else:
             self.host = ansible_adhoc(become=True, *args, **kwargs)[hostname]
             self.mgmt_ip = self.host.options["inventory_manager"].get_host(hostname).vars["ansible_host"]
+            if "ansible_hostv6" in self.host.options["inventory_manager"].get_host(hostname).vars:
+                self.mgmt_ipv6 = self.host.options["inventory_manager"].get_host(hostname).vars["ansible_hostv6"]
+            else:
+                self.mgmt_ipv6 = None
         self.hostname = hostname
 
     def __getattr__(self, module_name):

tests/ip/test_mgmt_ipv6_only.py

@@ -5,6 +5,7 @@
 from tests.bgp.test_bgp_fact import run_bgp_facts
 from tests.test_features import run_show_features
 from tests.tacacs.test_ro_user import ssh_remote_run
+from tests.ntp.test_ntp import run_ntp
 from tests.common.helpers.assertions import pytest_require
 from tests.tacacs.conftest import tacacs_creds, check_tacacs_v6 # noqa F401
 from tests.syslog.test_syslog import run_syslog, check_default_route # noqa F401
@@ -17,6 +18,11 @@
 ]
 
 
+def pytest_generate_tests(metafunc):
+    if "ptf_use_ipv6" in metafunc.fixturenames:
+        metafunc.parametrize("ptf_use_ipv6", [True], scope="module")
+
+
 @pytest.fixture(autouse=True)
 def ignore_expected_loganalyzer_exception(loganalyzer):
     ignore_regex = [
@@ -129,3 +135,8 @@ def test_rw_user_ipv6_only(localhost, duthosts, enum_rand_one_per_hwsku_hostname
     res = ssh_remote_run(localhost, dutipv6, tacacs_creds['tacacs_rw_user'],
                          tacacs_creds['tacacs_rw_user_passwd'], "cat /etc/passwd")
     check_output(res, 'testadmin', 'remote_user_su')
+
+
+def test_ntp_ipv6_only(duthosts, rand_one_dut_hostname,
+                                  convert_and_restore_config_db_to_ipv6_only, setup_ntp): # noqa F811
+    run_ntp(duthosts, rand_one_dut_hostname, setup_ntp)

tests/ntp/test_ntp.py

@@ -15,6 +15,11 @@
 TIME_FORWARD = 3600
 
 
+def pytest_generate_tests(metafunc):
+    if "ptf_use_ipv6" in metafunc.fixturenames:
+        metafunc.parametrize("ptf_use_ipv6", [False, True], scope="module")
+
+
 def config_long_jump(duthost, enable=False):
     """change ntpd option to enable or disable long jump"""
     ntpsec_conf_stat = duthost.stat(path="/etc/ntpsec/ntp.conf")
@@ -40,7 +45,7 @@ def config_long_jump(duthost, enable=False):
 
 
 @pytest.fixture(scope="module")
-def setup_ntp(ptfhost, duthosts, rand_one_dut_hostname):
+def setup_ntp(ptfhost, duthosts, rand_one_dut_hostname, ptf_use_ipv6):
     """setup ntp client and server"""
     duthost = duthosts[rand_one_dut_hostname]
 
@@ -59,14 +64,14 @@ def setup_ntp(ptfhost, duthosts, rand_one_dut_hostname):
     for ntp_server in ntp_servers:
         duthost.command("config ntp del %s" % ntp_server)
 
-    duthost.command("config ntp add %s" % ptfhost.mgmt_ip)
+    duthost.command("config ntp add %s" % (ptfhost.mgmt_ipv6 if ptf_use_ipv6 else ptfhost.mgmt_ip))
 
     yield
 
     # stop ntp server
     ptfhost.service(name="ntp", state="stopped")
     # reset ntp client configuration
-    duthost.command("config ntp del %s" % ptfhost.mgmt_ip)
+    duthost.command("config ntp del %s" % (ptfhost.mgmt_ipv6 if ptf_use_ipv6 else ptfhost.mgmt_ip))
     for ntp_server in ntp_servers:
         duthost.command("config ntp add %s" % ntp_server)
     # The time jump leads to exception in lldp_syncd. The exception has been handled by lldp_syncd,
@@ -132,7 +137,7 @@ def test_ntp_long_jump_disabled(duthosts, rand_one_dut_hostname, setup_ntp, setu
         pytest.fail("NTP long jump disable failed")
 
 
-def test_ntp(duthosts, rand_one_dut_hostname, setup_ntp):
+def run_ntp(duthosts, rand_one_dut_hostname, setup_ntp):
     """ Verify that DUT is synchronized with configured NTP server """
     duthost = duthosts[rand_one_dut_hostname]
 
@@ -148,3 +153,7 @@ def test_ntp(duthosts, rand_one_dut_hostname, setup_ntp):
     duthost.service(name='ntp', state='restarted')
     pytest_assert(wait_until(720, 10, 0, check_ntp_status, duthost),
                   "NTP not in sync")
+
+
+def test_ntp(duthosts, rand_one_dut_hostname, setup_ntp):
+    run_ntp(duthosts, rand_one_dut_hostname, setup_ntp)