Update platform api server to support IPv6 (#20942)

What is the motivation for this PR?
Change platform api server so that HTTP requests can be received though IPv6 as an option

This will fix platform_tests/api/* tests using a mgmt IPv6 configuration.

Author: dayouliu1

tests/common/fixtures/duthost_utils.py

@@ -8,6 +8,7 @@
 import ipaddress
 import time
 import json
+import re
 
 from pytest_ansible.errors import AnsibleConnectionFailure
 from paramiko.ssh_exception import AuthenticationException
@@ -854,6 +855,30 @@ def wait_for_processes_and_bgp(dut):
     return duthosts
 
 
+@pytest.fixture(scope="module")
+def duthost_mgmt_ip(duthost):
+    """
+    Gets the management IP address (v4 or v6) on eth0.
+    Defaults to IPv4 on a dual stack configuration.
+    """
+    ipv4_regex = re.compile(r"(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/\d+")
+    ipv6_regex = re.compile(r"([a-fA-F0-9:]+)/\d+")
+
+    mgmt_interface = duthost.shell("show ip interface | egrep '^eth0 '", module_ignore_errors=True)["stdout"]
+    if mgmt_interface:
+        match = ipv4_regex.search(mgmt_interface)
+        if match:
+            return {"mgmt_ip": match.group(1), "version": "v4"}
+
+    mgmt_interface = duthost.shell("show ipv6 interface | egrep '^eth0 '", module_ignore_errors=True)["stdout"]
+    if mgmt_interface:
+        match = ipv6_regex.search(mgmt_interface)
+        if match:
+            return {"mgmt_ip": match.group(1), "version": "v6"}
+
+    pt_assert(False, "Failed to find duthost mgmt ip")
+
+
 def assert_addr_in_output(addr_set: Dict[str, List], hostname: str,
                           expect_exists: bool, cmd_output: str, cmd_desc: str):
     """

tests/common/helpers/platform_api/scripts/platform_api_server.py

@@ -2,6 +2,7 @@
 import inspect
 import json
 import os
+import socket
 import sys
 import syslog
 
@@ -18,6 +19,10 @@
 platform = sonic_platform.platform.Platform()
 
 
+class HTTPServerV6(HTTPServer):
+    address_family = socket.AF_INET6
+
+
 def obj_serialize(obj):
     ''' JSON serializer for objects not serializable by default json library code
         We simply return a dictionary containing the object's class and module
@@ -103,11 +108,15 @@ def do_platform_api(self):
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument('-p', '--port', type=int, help='port to listen to', required=True)
+    parser.add_argument('-6', '--ipv6', action='store_true', help='Set server to use IPv6', )
     args = parser.parse_args()
 
     syslog.openlog(SYSLOG_IDENTIFIER)
 
-    httpd = HTTPServer(('', args.port), PlatformAPITestService)
+    if args.ipv6:
+        httpd = HTTPServerV6(('::', args.port), PlatformAPITestService)
+    else:
+        httpd = HTTPServer(('', args.port), PlatformAPITestService)
     httpd.serve_forever()
 
     syslog.closelog()

tests/common/platform/device_utils.py

@@ -19,7 +19,8 @@
 from tests.common.platform.reboot_timing_constants import SERVICE_PATTERNS, OTHER_PATTERNS, SAIREDIS_PATTERNS, \
     OFFSET_ITEMS, TIME_SPAN_ITEMS, REQUIRED_PATTERNS
 from tests.common.devices.duthosts import DutHosts
-from tests.common.plugins.ansible_fixtures import ansible_adhoc  # noqa F401
+from tests.common.plugins.ansible_fixtures import ansible_adhoc  # noqa: F401
+from tests.common.fixtures.duthost_utils import duthost_mgmt_ip  # noqa: F401
 
 """
 Helper script for fanout switch operations
@@ -52,7 +53,7 @@
 SERVER_FILE = 'platform_api_server.py'
 SERVER_PORT = 8000
 IPTABLES_PREPEND_RULE_CMD = 'iptables -I INPUT 1 -p tcp -m tcp --dport {} -j ACCEPT'.format(SERVER_PORT)
-
+IP6TABLES_PREPEND_RULE_CMD = 'ip6tables -I INPUT 1 -p tcp -m tcp --dport {} -j ACCEPT'.format(SERVER_PORT)
 test_report = dict()
 
 
@@ -1080,9 +1081,10 @@ def advanceboot_neighbor_restore(duthosts, enum_rand_one_per_hwsku_frontend_host
 
 
 @pytest.fixture(scope='function')
-def start_platform_api_service(duthosts, enum_rand_one_per_hwsku_hostname, localhost, request):
+def start_platform_api_service(duthosts, enum_rand_one_per_hwsku_hostname, duthost_mgmt_ip,  # noqa: F811
+                               localhost, request):
     duthost = duthosts[enum_rand_one_per_hwsku_hostname]
-    dut_ip = duthost.mgmt_ip
+    dut_ip = duthost_mgmt_ip['mgmt_ip']
 
     res = localhost.wait_for(host=dut_ip,
                              port=SERVER_PORT,
@@ -1097,12 +1099,15 @@ def start_platform_api_service(duthosts, enum_rand_one_per_hwsku_hostname, local
 
         supervisor_conf = [
             '[program:platform_api_server]',
-            'command=/usr/bin/python{} /opt/platform_api_server.py --port {}'.format('3' if py3_platform_api_available
-                                                                                     else '2', SERVER_PORT),
+            'command=/usr/bin/python{} /opt/platform_api_server.py --port {} {}'.format(
+                '3' if py3_platform_api_available else '2',
+                SERVER_PORT,
+                '--ipv6' if duthost_mgmt_ip['version'] == 'v6' else ''),
             'autostart=True',
             'autorestart=True',
             'stdout_logfile=syslog',
             'stderr_logfile=syslog',
+            'startsec=0',
         ]
         dest_path = os.path.join(os.sep, 'tmp', 'platform_api_server.conf')
         pmon_path = os.path.join(os.sep, 'etc', 'supervisor', 'conf.d', 'platform_api_server.conf')
@@ -1116,7 +1121,10 @@ def start_platform_api_service(duthosts, enum_rand_one_per_hwsku_hostname, local
         duthost.command('docker cp {} pmon:{}'.format(dest_path, pmon_path))
 
         # Prepend an iptables rule to allow incoming traffic to the HTTP server
-        duthost.command(IPTABLES_PREPEND_RULE_CMD)
+        if duthost_mgmt_ip['version'] == 'v6':
+            duthost.command(IP6TABLES_PREPEND_RULE_CMD)
+        else:
+            duthost.command(IPTABLES_PREPEND_RULE_CMD)
 
         # Reload the supervisor config and Start the HTTP server
         duthost.command('docker exec -i pmon supervisorctl reread')
@@ -1127,9 +1135,8 @@ def start_platform_api_service(duthosts, enum_rand_one_per_hwsku_hostname, local
 
 
 @pytest.fixture(scope='function')
-def platform_api_conn(duthosts, enum_rand_one_per_hwsku_hostname, start_platform_api_service):
-    duthost = duthosts[enum_rand_one_per_hwsku_hostname]
-    dut_ip = duthost.mgmt_ip
+def platform_api_conn(duthost_mgmt_ip, start_platform_api_service):  # noqa: F811
+    dut_ip = duthost_mgmt_ip['mgmt_ip']
 
     conn = http.client.HTTPConnection(dut_ip, 8000)
     try:
@@ -1140,7 +1147,7 @@ def platform_api_conn(duthosts, enum_rand_one_per_hwsku_hostname, start_platform
 
 @pytest.fixture(scope='module')
 def add_platform_api_server_port_nat_for_dpu(
-        ansible_adhoc, tbinfo, request, duthosts, enum_rand_one_per_hwsku_hostname):  # noqa F811
+        ansible_adhoc, tbinfo, request, duthosts, enum_rand_one_per_hwsku_hostname):  # noqa: F811
     '''
     This fixture is used to add a NAT rule to the DPU's eth0-midplane interface
     to forward traffic from NPU to the platform API server on DPU.
@@ -1168,15 +1175,15 @@ def add_platform_api_server_port_nat_for_dpu(
                 {SERVER_PORT} -j DNAT --to-destination {dpu_ip}:{SERVER_PORT}')
 
 
-def get_ansible_ssh_port(duthost, ansible_adhoc):  # noqa F811
+def get_ansible_ssh_port(duthost, ansible_adhoc):  # noqa: F811
     host = ansible_adhoc(become=True, args=[], kwargs={})[duthost.hostname]
     vm = host.options["inventory_manager"].get_host(duthost.hostname).vars
     ansible_ssh_port = vm.get("ansible_ssh_port", None)
     logger.info(f'ansible_ssh_port for {duthost.hostname} is {ansible_ssh_port}')
     return ansible_ssh_port
 
 
-def create_npu_host_based_on_dpu_info(ansible_adhoc, tbinfo, request, duthost): # noqa F811
+def create_npu_host_based_on_dpu_info(ansible_adhoc, tbinfo, request, duthost):  # noqa: F811
     '''
     Create a NPU host object based on DPU info
     E.g