[mpls][sonic-vpp] Enable MPLS data-plane tests on the VPP t1-lag testbed

.azure-pipelines/pr_test_scripts.yaml

@@ -694,6 +694,7 @@ t1-lag-vpp:
   - lldp/test_lldp.py
   - lldp/test_lldp_syncd.py
   - log_fidelity/test_bgp_shutdown.py
+  - mpls/test_mpls.py
   - pc/test_po_voq.py
   - pc/test_lag_member.py
   - pc/test_po_update.py

ansible/library/generate_golden_config_db.py

@@ -1338,6 +1338,21 @@ def generate(self):
         if self.has_otel_image():
             config = self.overwrite_feature_golden_config_db_singleasic(config, "otel", "enabled", "enabled")
 
+        # Register the mpls feature on the sonic-vpp testbeds so the MPLS data-plane
+        # tests (tests/mpls) are not skipped by the "'mpls' not in feature_status"
+        # condition in tests_mark_conditions.yaml. The VPP SAI implementation
+        # supports MPLS (INSEG disposition/imposition).
+        #
+        # The state is deliberately "disabled": mpls is a config flag, not a
+        # containerized service, so there is no "mpls" docker. Registering it as
+        # "enabled" would make the image's monit container_checker report
+        # "Expected containers not running: mpls" and fail the sanity check for
+        # every test on this platform. The condition above only tests for the
+        # presence of the key, so "disabled" is enough to un-skip the tests.
+        if "vpp" in self.topo_name:
+            config = self.overwrite_feature_golden_config_db_singleasic(
+                config, "mpls", auto_restart="disabled", state="disabled")
+
         # Disable dash-ha feature for all multi-asic platforms
         if multi_asic.is_multi_asic():
             config = self.overwrite_feature_golden_config_db_multiasic(config, "dash-ha", feature_data={

tests/common/plugins/conditional_mark/tests_mark_conditions_sonic_vpp.yaml

@@ -401,10 +401,12 @@ memory_checker/test_memory_checker.py::test_monit_reset_counter_failure:
 #######################################
 #####           MPLS              #####
 #######################################
-mpls/test_mpls.py:
+mpls/test_mpls.py::TestBasicMpls::test_push_label:
   skip:
     reason: >
-            Unsupported
+            MPLS push is not testable here: the test injects the push route
+            directly into ROUTE_TABLE and orchagent does not install that route
+            into ASIC_DB, so it never reaches the SAI backend.
     conditions_logical_operator: or
     conditions:
       - "asic_type in ['vpp']"

tests/mpls/conftest.py

@@ -14,6 +14,22 @@
 LABEL_DEL_ROUTES = 'label_del_routes'
 
 
+def _resolve_ptf_port_ids(dut_port, mg_facts):
+    """Resolve a DUT L3 interface to its PTF port indices.
+
+    On t1-lag the spine/tor facing interfaces can be PortChannels, which are not
+    present in minigraph_port_indices. Resolve such a PortChannel to the PTF port
+    indices of its physical member ports. A physical interface resolves to a
+    single-element list.
+    """
+    portchannels = mg_facts.get('minigraph_portchannels', {})
+    if dut_port in portchannels:
+        members = portchannels[dut_port]['members']
+    else:
+        members = [dut_port]
+    return [mg_facts['minigraph_port_indices'][member] for member in members]
+
+
 @pytest.fixture(scope='module')
 def setup(duthost, tbinfo, ptfadapter):
     """
@@ -22,9 +38,24 @@ def setup(duthost, tbinfo, ptfadapter):
     :param tbinfo: fixture provides information about testbed
     :return: dictionary with all test required information
     """
-    if tbinfo['topo']['name'] not in ('t1'):
+    if tbinfo['topo']['type'] != 't1':
         pytest.skip('Unsupported topology')
 
+    # Enabling MPLS on an interface makes intfmgrd run
+    # "sysctl -w net.mpls.conf.<intf>.input=1", which needs the mpls_router kernel
+    # module. The module ships in the image but nothing loads it, so without this
+    # the sysctl fails and is logged as an ERR. sonic-swss's own MPLS test loads it
+    # the same way. Left loaded on teardown: modprobe is idempotent and unloading
+    # could disrupt anything else using MPLS.
+    if duthost.facts['asic_type'] == 'vpp':
+        result = duthost.shell('modprobe mpls_router', module_ignore_errors=True)
+        if result['rc'] != 0:
+            # Not fatal here: let the test itself fail on the resulting syslog
+            # error rather than hiding a genuine loss of kernel MPLS support
+            # behind a setup failure.
+            logger.warning('Failed to load mpls_router: %s. Enabling MPLS on an '
+                           'interface will log a setIntfMpls error.', result['stderr'])
+
     # gather ansible facts
     mg_facts = duthost.minigraph_facts(host=duthost.hostname)['ansible_facts']
     host_facts = duthost.setup()['ansible_facts']
@@ -60,15 +91,20 @@ def setup(duthost, tbinfo, ptfadapter):
     logger.info('spine_ports: {}'.format(spine_ports))
     logger.info('tor_addr: {}'.format(tor_addr))
 
+    # The test needs both a T2-facing ingress and a T0-facing egress interface.
+    # Some t1 variants (e.g. t1-backend, whose neighbors are all BT0) have no T2
+    # peer at all, so bail out cleanly instead of failing later in random.choice().
+    if not spine_ports or not tor_ports:
+        pytest.skip('Topology has no T2-facing ({}) or T0-facing ({}) interface'
+                    .format(len(spine_ports), len(tor_ports)))
+
     for dut_port in tor_ports:
-        port_id = mg_facts['minigraph_port_indices'][dut_port]
-        tor_ports_ids[dut_port] = port_id
+        tor_ports_ids[dut_port] = _resolve_ptf_port_ids(dut_port, mg_facts)
         ansible_port = 'ansible_'+dut_port
         tor_mac[dut_port] = host_facts[ansible_port]['macaddress']
 
     for dut_port in spine_ports:
-        port_id = mg_facts['minigraph_port_indices'][dut_port]
-        spine_ports_ids[dut_port] = port_id
+        spine_ports_ids[dut_port] = _resolve_ptf_port_ids(dut_port, mg_facts)
         ansible_port = 'ansible_'+dut_port
         spine_mac[dut_port] = host_facts[ansible_port]['macaddress']
 
@@ -78,8 +114,10 @@ def setup(duthost, tbinfo, ptfadapter):
     src_port = random.choice(spine_ports)
     dst_port = random.choice(tor_ports)
 
+    # dst_pid is the list of egress PortChannel member PTF ports (verify on any member).
+    # src_pid is a single ingress member PTF port used to inject the test packet.
     dst_pid = tor_ports_ids[dst_port]
-    src_pid = spine_ports_ids[src_port]
+    src_pid = spine_ports_ids[src_port][0]
 
     dst_mac = tor_mac[dst_port]
     src_mac = spine_mac[src_port]

tests/mpls/test_mpls.py

@@ -106,7 +106,6 @@ def expected_mask_ip_packet(self, pkt):
         exp_pkt['Ethernet'].remove_payload()
         exp_pkt /= pkt1
         exp_pkt = mask.Mask(exp_pkt)
-        exp_pkt = mask.Mask(exp_pkt)
         exp_pkt.set_do_not_care_scapy(packet.Ether, 'dst')
         exp_pkt.set_do_not_care_scapy(packet.Ether, 'src')
         exp_pkt.set_do_not_care_scapy(packet.IP, 'chksum')
@@ -198,7 +197,7 @@ def test_pop_label(self, setup, ptfadapter):
         ptfadapter.dataplane.flush()
         testutils.send(ptfadapter, src_pid, pkt)
         try:
-            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=[dst_pid])
+            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=dst_pid)
             logger.info(res)
         except Exception as e:
             self.teardown_labels(setup)
@@ -222,7 +221,7 @@ def test_swap_label(self, setup, ptfadapter):
         ptfadapter.dataplane.flush()
         testutils.send(ptfadapter, src_pid, pkt)
         try:
-            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=[dst_pid])
+            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=dst_pid)
             logger.info(res)
         except Exception as e:
             self.teardown_labels(setup)
@@ -255,7 +254,7 @@ def test_push_label(self, setup, ptfadapter):
         testutils.send(ptfadapter, src_pid, pkt)
 
         try:
-            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=[dst_pid])
+            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=dst_pid)
             logger.info(res)
         except Exception as e:
             self.teardown_labels(setup)
@@ -280,7 +279,7 @@ def test_swap_labelstack(self, setup, ptfadapter):
         testutils.send(ptfadapter, src_pid, pkt)
 
         try:
-            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=[dst_pid])
+            res = testutils.verify_packet_any_port(ptfadapter, exp_pkt, ports=dst_pid)
             logger.info(res)
         except Exception as e:
             self.teardown_labels(setup)