sonic-utilities: Add CLI commands to set sflow drop-monitor-limit

* added CLI: config sflow drop-monitor-limit 1-999 (0 to disable)
* added line to show sflow output to indicate current setting
* added test to ensure that out-of-range value is denied

The effect is to add the redis field drop_monitor_limit to the
sflow configuration table in redis, as described in
pull-request #1484 on the sonic-net/SONiC repo.

Note: hsflowd version 2.0.52 will apply this setting.
Older versions will ignore it.

Signed-off-by: Neil McKee  neil.mckee@inmon.com

config/main.py

@@ -34,7 +34,7 @@
 from utilities_common.intf_filter import parse_interface_in_filter
 from utilities_common import bgp_util
 import utilities_common.cli as clicommon
-from utilities_common.helper import get_port_pbh_binding, get_port_acl_binding, update_config
+from utilities_common.helper import get_port_pbh_binding, get_port_acl_binding
 from utilities_common.general import load_db_config, load_module_from_source
 from .validated_config_db_connector import ValidatedConfigDBConnector
 import utilities_common.multi_asic as multi_asic_util
@@ -1771,7 +1771,7 @@ def load_minigraph(db, no_service_restart, traffic_shift_away, override_config,
                 cfggen_namespace_option = ['-n', str(namespace)]
             clicommon.run_command([db_migrator, '-o', 'set_version'] + cfggen_namespace_option)
 
-    # Keep device isolated with TSA
+    # Keep device isolated with TSA 
     if traffic_shift_away:
         clicommon.run_command(["TSA"], display_cmd=True)
         if override_config:
@@ -1950,7 +1950,6 @@ def override_config_table(db, input_config_db, dry_run):
             ns_config_input = config_input
         # Generate sysinfo if missing in ns_config_input
         generate_sysinfo(current_config, ns_config_input, ns)
-        # Use deepcopy by default to avoid modifying input config
         updated_config = update_config(current_config, ns_config_input)
 
         yang_enabled = device_info.is_yang_config_validation_enabled(config_db)
@@ -1986,6 +1985,14 @@ def validate_config_by_cm(cm, config_json, jname):
         sys.exit(1)
 
 
+def update_config(current_config, config_input):
+    updated_config = copy.deepcopy(current_config)
+    # Override current config with golden config
+    for table in config_input:
+        updated_config[table] = config_input[table]
+    return updated_config
+
+
 def override_config_db(config_db, config_input):
     # Deserialized golden config to DB recognized format
     sonic_cfggen.FormatConverter.to_deserialized(config_input)
@@ -2049,21 +2056,9 @@ def synchronous_mode(sync_mode):
               config reload -y \n
     Option 2. systemctl restart swss""" % sync_mode)
 
-#
-# 'suppress-fib-pending' command ('config suppress-fib-pending ...')
-#
-@config.command('suppress-fib-pending')
-@click.argument('state', metavar='<enabled|disabled>', required=True, type=click.Choice(['enabled', 'disabled']))
-@clicommon.pass_db
-def suppress_pending_fib(db, state):
-    ''' Enable or disable pending FIB suppression. Once enabled, BGP will not advertise routes that are not yet installed in the hardware '''
-
-    config_db = db.cfgdb
-    config_db.mod_entry('DEVICE_METADATA' , 'localhost', {"suppress-fib-pending" : state})
-
 #
 # 'yang_config_validation' command ('config yang_config_validation ...')
-#
+# 
 @config.command('yang_config_validation')
 @click.argument('yang_config_validation', metavar='<enable|disable>', required=True)
 def yang_config_validation(yang_config_validation):
@@ -6735,6 +6730,30 @@ def global_sample_direction(ctx, direction):
 def is_valid_sample_rate(rate):
     return rate.isdigit() and int(rate) in range(256, 8388608 + 1)
 
+#
+# 'sflow' command ('config sflow drop-monitor-limit ...')
+#
+@sflow.command('drop-monitor-limit')
+@click.argument('limit',  metavar='<drop_monitor_limit>', required=True,
+                type=click.IntRange(0, 999))
+@click.pass_context
+def drop_monitor_limit_int(ctx, limit):
+    """Set rate limit for drop notifications (0 to disable)"""
+    if ADHOC_VALIDATION:
+        if limit not in range(1, 999) and limit != 0:
+            ctx.fail("Rate limit not in the valid range, must be between 1-999 (0 to disable)")
+
+    config_db = ValidatedConfigDBConnector(ctx.obj['db'])
+    sflow_tbl = config_db.get_table('SFLOW')
+
+    if not sflow_tbl:
+        sflow_tbl = {'global': {'admin_state': 'down'}}
+
+    sflow_tbl['global']['drop_monitor_limit'] = limit
+    try:
+        config_db.mod_entry('SFLOW', 'global', sflow_tbl['global'])
+    except ValueError as e:
+        ctx.fail("Invalid ConfigDB. Error: {}".format(e))
 
 #
 # 'sflow interface' group

show/sflow.py

@@ -86,6 +86,12 @@ def show_sflow_global(config_db):
     else:
         click.echo("default")
 
+    click.echo("  sFlow Drop Rate Limit:".ljust(30), nl=False)
+    if (sflow_info and 'drop_monitor_limit' in sflow_info['global']):
+        click.echo("{}".format(sflow_info['global']['drop_monitor_limit']))
+    else:
+        click.echo("0")
+
     sflow_info = config_db.get_table('SFLOW_COLLECTOR')
     click.echo("\n  {} Collectors configured:".format(len(sflow_info)))
     for collector_name in sorted(list(sflow_info.keys())):

tests/sflow_test.py

@@ -21,6 +21,7 @@
   sFlow Sample Direction:     both
   sFlow Polling Interval:     0
   sFlow AgentID:              default
+  sFlow Drop Rate Limit:      0
 
   2 Collectors configured:
     Name: prod                IP addr: fe80::6e82:6aff:fe1e:cd8e UDP port: 6343   VRF: mgmt
@@ -267,6 +268,56 @@ def test_config_sflow_polling_interval(self):
 
         return
 
+    def test_config_sflow_drop_monitor_limit_yang_validation(self):
+        db = Db()
+        runner = CliRunner()
+        obj = {'db':db.cfgdb}
+
+        config.ADHOC_VALIDATION = False
+        result = runner.invoke(config.config.commands["sflow"].
+            commands["drop-monitor-limit"], ["1000"], obj=obj)
+        print(result.exit_code, result.output)
+        assert "not in the valid range" in result.output
+
+    def test_config_sflow_drop_monitor_limit(self):
+        db = Db()
+        runner = CliRunner()
+        obj = {'db':db.cfgdb}
+        config.ADHOC_VALIDATION = True
+
+        # set to 1 out of range
+        result = runner.invoke(config.config.commands["sflow"].
+            commands["drop-monitor-limit"], ["1000"], obj=obj)
+        print(result.exit_code, result.output)
+        assert result.exit_code != 0
+        assert "not in the valid range" in result.output
+
+        # set to 50
+        result = runner.invoke(config.config.commands["sflow"].
+            commands["drop-monitor-limit"], ["50"], obj=obj)
+        print(result.exit_code, result.output)
+        assert result.exit_code == 0
+
+        # change the expected output
+        global show_sflow_output
+        show_sflow_output_local = show_sflow_output.replace(
+            'sFlow Drop Rate Limit:      0',
+            'sFlow Drop Rate Limit:      50')
+
+        # run show and check
+        result = runner.invoke(show.cli.commands["sflow"], [], obj=db)
+        print(result.exit_code, result.output)
+        assert result.exit_code == 0
+        assert result.output == show_sflow_output_local
+
+        #reset to 0, no need to verify this one
+        result = runner.invoke(config.config.commands["sflow"].
+            commands["polling-interval"], ["0"], obj=obj)
+        print(result.exit_code, result.output)
+        assert result.exit_code == 0
+
+        return
+
     @patch("config.main.ConfigDBConnector.get_table", mock.Mock(return_value={'Ethernet1': {'admin_state': 'sample_state'}}))
     @patch("validated_config_db_connector.device_info.is_yang_config_validation_enabled", mock.Mock(return_value=True))
     @patch("config.validated_config_db_connector.ValidatedConfigDBConnector.validated_mod_entry", mock.Mock(side_effect=ValueError))