Removed hardcoded priorities for background flows and incorporated the changes to pick background priorities from available list of priorities.

[kamalsahu0001]

Description of PR

Previously, the background priorities are hardcoded.
Now the changes are incorporated to randomly pick priorities from available list of background priorities.
Each time, it will pick different background priorities so that it can cover all different priorities.

Summary:
Fixes # (issue)
Fixed both helper file and test case to pick priorities on the fly.

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• New Test case
  • Skipped for non-supported platforms
• [ x] Test case improvement

Back port request

• 202205
• 202305
• 202311
• 202405
• 202411
• 202505

Approach

What is the motivation for this PR?

To cover all available list of priorities.

How did you do it?

How did you verify/test it?

Tested against a DUT internally

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[kamalsahu0001]

snappi_tests/pfc/test_lossless_response_to_external_pause_storms.py::test_lossless_response_to_external_pause_storms_test[tgen_port_info0]
------------------------------------------------------- live log setup -------------------------------------------------------
20:08:22 init.set_default L0053 INFO | Completeness level not set during test execution. Setting to default level: CompletenessLevel.basic
20:08:22 init.check_test_completeness L0151 INFO | Test has no defined levels. Continue without test completeness checks
20:08:22 conftest.enhance_inventory L0321 INFO | Inventory file: ['../ansible/snappi-sonic']
20:08:25 ptfhost_utils.run_icmp_responder_session L0310 INFO | Skip running icmp_responder at session level, it is only for dualtor testbed with active-active mux ports.
20:08:25 init._sanity_check L0431 INFO | Skip sanity check according to command line argument
20:08:25 conftest.collect_before_test L2705 INFO | Dumping Disk and Memory Space information before test on sonic-s6100-dut1
20:08:26 conftest.collect_before_test L2709 INFO | Collecting core dumps before test on sonic-s6100-dut1
20:08:26 conftest.collect_before_test L2718 INFO | Collecting running config before test on sonic-s6100-dut1
20:08:28 conftest.temporarily_disable_route_check L2984 INFO | Skipping temporarily_disable_route_check fixture
20:08:28 conftest.generate_params_dut_hostname L1506 INFO | Using DUTs ['sonic-s6100-dut1'] in testbed 'vms-snappi-sonic'
20:08:28 conftest.set_rand_one_dut_hostname L0655 INFO | Randomly select dut sonic-s6100-dut1 for testing
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture enable_packet_aging_after_test setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture enable_packet_aging_after_test setup ends --------------------
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture rand_lossless_prio setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture rand_lossless_prio setup ends --------------------
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture rand_lossy_prio setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture rand_lossy_prio setup ends --------------------
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture start_pfcwd_after_test setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture start_pfcwd_after_test setup ends --------------------
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture disable_voq_watchdog setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture disable_voq_watchdog setup ends --------------------
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture number_of_tx_rx_ports setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture number_of_tx_rx_ports setup ends --------------------
20:08:28 init._fixture_func_decorator L0069 INFO | -------------------- fixture snappi_api_serv_ip setup starts --------------------
20:08:28 init._fixture_func_decorator L0076 INFO | -------------------- fixture snappi_api_serv_ip setup ends --------------------
20:08:28 init._fixture_func_decorator L0069 INFO | -------------------- fixture snappi_api_serv_port setup starts --------------------
20:08:28 init._fixture_func_decorator L0076 INFO | -------------------- fixture snappi_api_serv_port setup ends --------------------
20:08:28 init._fixture_generator_decorator L0081 INFO | -------------------- fixture snappi_api setup starts --------------------
20:08:28 init._fixture_generator_decorator L0085 INFO | -------------------- fixture snappi_api setup ends --------------------
20:08:29 conftest.rand_one_dut_front_end_hostname L0691 INFO | Randomly select dut sonic-s6100-dut1 for testing
20:08:29 init._fixture_func_decorator L0069 INFO | -------------------- fixture prio_dscp_map setup starts --------------------
20:08:30 init._fixture_func_decorator L0076 INFO | -------------------- fixture prio_dscp_map setup ends --------------------
20:08:30 init._fixture_func_decorator L0069 INFO | -------------------- fixture lossless_prio_list setup starts --------------------
20:08:31 init._fixture_func_decorator L0076 INFO | -------------------- fixture lossless_prio_list setup ends --------------------
20:08:31 init._fixture_func_decorator L0069 INFO | -------------------- fixture get_snappi_ports setup starts --------------------
20:08:32 conftest.generate_port_lists L1598 INFO | Generate dut_port_map: {'sonic-s6100-dut1': ['sonic-s6100-dut1|Ethernet0', 'sonic-s6100-dut1|Ethernet8', 'sonic-s6100-dut1|Ethernet16', 'sonic-s6100-dut1|Ethernet24']}
20:08:32 conftest.generate_port_lists L1621 INFO | Generate port_list: ['sonic-s6100-dut1|Ethernet0', 'sonic-s6100-dut1|Ethernet8', 'sonic-s6100-dut1|Ethernet16', 'sonic-s6100-dut1|Ethernet24']
20:08:32 init._fixture_func_decorator L0069 INFO | -------------------- fixture get_snappi_ports_single_dut setup starts --------------------
20:08:32 init._fixture_func_decorator L0076 INFO | -------------------- fixture get_snappi_ports_single_dut setup ends --------------------
20:08:32 init._fixture_func_decorator L0076 INFO | -------------------- fixture get_snappi_ports setup ends --------------------
20:08:32 init._fixture_func_decorator L0069 INFO | -------------------- fixture snappi_port_selection setup starts --------------------
20:08:32 init._fixture_func_decorator L0076 INFO | -------------------- fixture snappi_port_selection setup ends --------------------
20:08:32 init.loganalyzer L0074 INFO | Log analyzer is disabled
20:08:32 init.memory_utilization L0140 INFO | Hostname: sonic-s6100-dut1, Hwsku: Accton-AS9716-32D, Platform: x86_64-accton_as9716_32d-r0
20:08:32 memory_utilization.register_command L0023 INFO | Registering command: name=monit, cmd=sudo monit status, memory_params={'memory_usage': {'memory_increase_threshold': {'type': 'value', 'value': 10}, 'memory_high_threshold': {'type': 'value', 'value': 70}}}, memory_check=<function parse_monit_status_output at 0x7f2acc03d160>
20:08:32 memory_utilization.register_command L0023 INFO | Registering command: name=top, cmd=top -b -n 1, memory_params={'bgpd': {'memory_increase_threshold': {'type': 'value', 'value': 128}, 'memory_high_threshold': None}, 'zebra': {'memory_increase_threshold': {'type': 'value', 'value': 128}, 'memory_high_threshold': None}}, memory_check=<function parse_top_output at 0x7f2acc035940>
20:08:32 memory_utilization.register_command L0023 INFO | Registering command: name=free, cmd=free -m, memory_params={'used': {'memory_increase_threshold': {'type': 'percentage', 'value': '20%'}, 'memory_high_threshold': None}}, memory_check=<function parse_free_output at 0x7f2acc03d0d0>
20:08:32 memory_utilization.register_command L0023 INFO | Registering command: name=docker, cmd=docker stats --no-stream, memory_params={'snmp': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 4}}, 'pmon': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 8}}, 'lldp': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 4}}, 'gnmi': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 6}}, 'radv': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 3}}, 'syncd': {'memory_increase_threshold': {'type': 'value', 'value': 5}, 'memory_high_threshold': {'type': 'value', 'value': 18}}, 'bgp': {'memory_increase_threshold': {'type': 'value', 'value': 4}, 'memory_high_threshold': {'type': 'value', 'value': 14}}, 'teamd': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 5}}, 'swss': {'memory_increase_threshold': {'type': 'value', 'value': 3}, 'memory_high_threshold': {'type': 'value', 'value': 8}}, 'database': {'memory_increase_threshold': {'type': 'value', 'value': 2}, 'memory_high_threshold': {'type': 'value', 'value': 6}}}, memory_check=<function parse_docker_stats_output at 0x7f2acc03d1f0>
20:08:32 memory_utilization.register_command L0023 INFO | Registering command: name=frr_bgp, cmd=vtysh -c "show memory bgp", memory_params={'used': {'memory_increase_threshold': [{'type': 'percentage', 'value': '50%'}, {'type': 'value', 'value': 64}, {'type': 'comparison', 'value': 'max'}], 'memory_high_threshold': {'type': 'value', 'value': 256}}}, memory_check=<function parse_frr_memory_output at 0x7f2acc03d280>
20:08:32 memory_utilization.register_command L0023 INFO | Registering command: name=frr_zebra, cmd=vtysh -c "show memory zebra", memory_params={'used': {'memory_increase_threshold': [{'type': 'percentage', 'value': '50%'}, {'type': 'value', 'value': 64}, {'type': 'comparison', 'value': 'max'}], 'memory_high_threshold': {'type': 'value', 'value': 128}}}, memory_check=<function parse_frr_memory_output at 0x7f2acc03d280>
20:08:32 init._fixture_generator_decorator L0081 INFO | -------------------- fixture disable_pfcwd setup starts --------------------
20:08:33 init._fixture_generator_decorator L0085 INFO | -------------------- fixture disable_pfcwd setup ends --------------------
20:08:33 init._fixture_func_decorator L0069 INFO | -------------------- fixture tgen_port_info setup starts --------------------
20:08:37 init._fixture_func_decorator L0076 INFO | -------------------- fixture tgen_port_info setup ends --------------------
20:08:43 init.pytest_runtest_setup L0064 INFO | Before test: collected memory_values {'before_test': {'sonic-s6100-dut1': {'monit': {'memory_usage': 20.4}, 'top': {'zebra': 19.6, 'bgpd': 21.6}, 'free': {'used': 2833}, 'docker': {'snmp': 0.4, 'lldp': 0.4, 'radv': 0.2, 'syncd': 3.8, 'bgp': 0.5, 'teamd': 0.3, 'swss': 0.5, 'pmon': 0.8, 'database': 0.9}, 'frr_bgp': {'used': 7.4}, 'frr_zebra': {'used': 4.8}}}, 'after_test': {'sonic-s6100-dut1': {}}}
------------------------------------------------------- live log call --------------------------------------------------------
20:08:43 test_lossless_response_to_external_pause L0072 INFO | Selected two random lossy background priorities:[6, 1]
20:08:44 connection._warn L0336 WARNING| Verification of certificates is disabled
20:08:44 connection._info L0333 INFO | Determining the platform and rest_port using the 10.36.79.8 address...
20:08:44 connection._warn L0336 WARNING| Unable to connect to http://10.36.79.8:443.
20:08:44 connection._info L0333 INFO | Connection established to https://10.36.79.8:443 on linux
20:09:00 connection._info L0333 INFO | Using IxNetwork api server version 10.25.2406.6
20:09:00 connection._info L0333 INFO | User info IxNetwork/ixnetworkweb/admin-79-30215
20:09:00 snappi_api.info L1488 INFO | snappi-1.32.0
20:09:00 snappi_api.info L1488 INFO | snappi_ixnetwork-1.31.2
20:09:00 snappi_api.info L1488 INFO | ixnetwork_restpy-1.7.0
20:09:01 snappi_api.info L1488 INFO | Config validation 0.016s
20:09:06 snappi_api.info L1488 INFO | Ports configuration 4.707s
20:09:06 snappi_api.info L1488 INFO | Captures configuration 0.159s
20:09:09 snappi_api.info L1488 INFO | Add location hosts [10.36.79.8] 2.302s
20:09:11 snappi_api.info L1488 INFO | Location hosts ready [10.36.79.8] 2.234s
20:09:12 snappi_api.info L1488 INFO | Speed conversion is not require for (port.name, speed) : [('Port 0', 'aresOneOneByFourHundredGigNonFanOut'), ('Port 1', 'aresOneOneByFourHundredGigNonFanOut'), ('Port 2', 'aresOneOneByFourHundredGigNonFanOut'), ('Port 3', 'aresOneOneByFourHundredGigNonFanOut')]
20:09:12 snappi_api.info L1488 INFO | Aggregation mode speed change 0.322s
20:09:12 snappi_api.info L1488 INFO | Location preemption [10.36.79.8;1;8, 10.36.79.8;1;5, 10.36.79.8;1;6, 10.36.79.8;1;7] 0.090s
20:09:34 snappi_api.info L1488 INFO | Location connect [Port 0, Port 1, Port 2, Port 3] 21.731s
20:09:34 snappi_api.info L1488 INFO | Location state check [Port 0, Port 1, Port 2, Port 3] 0.325s
20:09:34 snappi_api.info L1488 INFO | Location configuration 28.168s
20:09:39 snappi_api.info L1488 INFO | Layer1 configuration 4.427s
20:09:39 snappi_api.info L1488 INFO | Lag Configuration 0.166s
20:09:39 snappi_api.info L1488 INFO | Convert device config : 0.248s
20:09:39 snappi_api.info L1488 INFO | Create IxNetwork device config : 0.000s
20:09:40 snappi_api.info L1488 INFO | Push IxNetwork device config : 1.041s
20:09:40 snappi_api.info L1488 INFO | Devices configuration 1.377s
20:09:46 snappi_api.info L1488 INFO | Flows configuration 5.828s
20:09:57 snappi_api.info L1488 INFO | Start interfaces 10.151s
20:09:57 snappi_api.info L1488 INFO | IxNet - The Traffic Item was modified. Please perform a Traffic Generate to update the associated traffic Flow Groups
20:09:57 traffic_generation.run_traffic L0433 INFO | Wait for Arp to Resolve ...
20:10:07 traffic_generation.run_traffic L0456 INFO | Starting transmit on all flows ...
20:10:12 snappi_api.info L1488 INFO | Flows generate/apply 4.498s
20:10:24 snappi_api.info L1488 INFO | Flows clear statistics 11.561s
20:10:24 snappi_api.info L1488 INFO | Captures start 0.000s
20:10:28 snappi_api.info L1488 INFO | Flows start 4.131s
20:10:32 traffic_generation.run_traffic L0502 INFO | Polling TGEN for in-flight traffic statistics...
20:10:40 traffic_generation.run_traffic L0510 INFO | Checking if all flows have stopped. Attempt #1
20:10:43 traffic_generation.run_traffic L0510 INFO | Checking if all flows have stopped. Attempt #2
20:10:45 traffic_generation.run_traffic L0510 INFO | Checking if all flows have stopped. Attempt #3
20:10:46 traffic_generation.run_traffic L0517 INFO | All test and background traffic flows stopped
20:10:48 traffic_generation.run_traffic L0540 INFO | Dumping per-flow statistics
20:10:49 traffic_generation.run_traffic L0542 INFO | Stopping transmit on all remaining flows
PASSED [100%]
----------------------------------------------------- live log teardown -----------------------------------------------------
-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
--------------------------------------------------- live log sessionfinish ---------------------------------------------------
20:12:52 init.pytest_terminal_summary L0067 INFO | Can not get Allure report URL. Please check logs
========================================= 1 passed, 16 warnings in 273.55s (0:04:33) =========================================
INFO:root:Can not get Allure report URL. Please check logs

[sdszhang]

lgtm

[mssonicbld]

Cherry-pick PR to 202505: #19834