Add incremental QOS config tests (#4580)

tests/common/helpers/dut_utils.py

@@ -260,3 +260,23 @@ def verify_features_state(duthost):
         logger.info("The state of '{}' is valid.".format(feature_name))
 
     return True
+
+
+def verify_orchagent_running_or_assert(duthost):
+    """
+    Verifies that orchagent is running, asserts otherwise
+
+    Args: 
+        duthost: Device Under Test (DUT)
+    """
+
+    def _orchagent_running():
+        cmds = 'docker exec swss supervisorctl status orchagent' 
+        output = duthost.shell(cmds, module_ignore_errors=True)
+        pytest_assert(not output['rc'], "Unable to check orchagent status output")
+        return 'RUNNING' in output['stdout']
+
+    pytest_assert(
+        wait_until(120, 10, 0, _orchagent_running),
+        "Orchagent is not running"
+    )

tests/generic_config_updater/test_incremental_qos.py

@@ -0,0 +1,93 @@
+import logging
+import json
+import pytest
+
+from tests.common.helpers.assertions import pytest_assert
+from tests.common.utilities import wait_until
+from tests.common.config_reload import config_reload
+from tests.common.helpers.dut_utils import verify_orchagent_running_or_assert
+from tests.generic_config_updater.gu_utils import apply_patch, expect_op_success, expect_res_success, expect_op_failure
+from tests.generic_config_updater.gu_utils import generate_tmpfile, delete_tmpfile
+
+pytestmark = [
+    pytest.mark.topology('t0'),
+    pytest.mark.asic('mellanox')
+]
+
+logger = logging.getLogger(__name__)
+
+
+@pytest.fixture(scope="module")
+def ensure_dut_readiness(duthost):
+    """
+    Setup/teardown fixture for incremental qos config update tst
+
+    Args:
+        duthost: DUT host object
+    """
+    config_tmpfile = generate_tmpfile(duthost)
+    logger.info("config_tmpfile {}".format(config_tmpfile))
+    logger.info("Backing up config_db.json")
+    duthost.shell("sudo cp /etc/sonic/config_db.json {}".format(config_tmpfile))
+    verify_orchagent_running_or_assert(duthost)
+
+    yield
+
+    verify_orchagent_running_or_assert(duthost)
+    logger.info("Restoring config_db.json")
+    duthost.shell("sudo cp {} /etc/sonic/config_db.json".format(config_tmpfile))
+    delete_tmpfile(duthost, config_tmpfile)
+    config_reload(duthost)
+
+    logger.info("TEARDOWN COMPLETED")
+
+
+def prepare_configdb_field(duthost, configdb_field, value):
+    """
+    Prepares config db by setting BUFFER_POOL key and field to specified value. If value is empty string or None, delete the current entry. 
+
+    Args:
+        duthost: DUT host object
+        configdb_field: field in config_db BUFFER_POOL table of the form key/value
+        value: BUFFER_POOL table value to be set
+    """
+
+    configdb_field_elements = configdb_field.split('/')
+    pytest_assert((len(configdb_field_elements) == 2), "Configdb field not identifiable")
+
+    key = configdb_field_elements[0]
+    field = configdb_field_elements[1]
+    logger.info("Setting configdb key: {} field: {} to value: {}".format(key, field, value))
+
+    if value:
+        cmd = "sonic-db-cli CONFIG_DB hset \"BUFFER_POOL|{}\" \"{}\" \"{}\" ".format(key, field, value)
+    else:
+        cmd = "sonic-db-cli CONFIG_DB del \"BUFFER_POOL|{}\" \"{}\" ".format(key, field)
+
+    verify_orchagent_running_or_assert(duthost)
+
+
+@pytest.mark.parametrize("configdb_field", ["ingress_lossless_pool/xoff", "ingress_lossless_pool/size", "egress_lossy_pool/size"])
+@pytest.mark.parametrize("operation", ["add", "replace", "remove"])
+@pytest.mark.parametrize("field_pre_status", ["existing", "nonexistent"])
+def test_incremental_qos_config_updates(duthost, ensure_dut_readiness, configdb_field, operation, field_pre_status):
+    operation_to_new_value_map = {"add": "678", "replace": "789", "remove": ""}
+    field_pre_status_to_value_map = {"existing": "567", "nonexistent": ""}
+
+    prepare_configdb_field(duthost, configdb_field, field_pre_status_to_value_map[field_pre_status]) 
+
+    tmpfile = generate_tmpfile(duthost)
+    logger.info("tmpfile {} created for json patch of field: {} and operation: {}".format(tmpfile, configdb_field, operation))
+
+    json_patch = [
+        {
+            "op": "{}".format(operation), 
+            "path": "/BUFFER_POOL/{}".format(configdb_field), 
+            "value": "{}".format(operation_to_new_value_map[operation])
+        }
+    ]
+
+    output = apply_patch(duthost, json_data=json_patch, dest_file=tmpfile)
+    expect_op_success(duthost, output)
+
+    delete_tmpfile(duthost, tmpfile)