[trim]: Add Packet Trimming CLI

Signed-off-by: Nazarii Hnydyn <[email protected]>

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**DEPENDS:**
1. sonic-net/sonic-swss-common#1001

**HLD:** sonic-net/SONiC#1898

#### What I did
* Implemented CLI for Packet Trimming feature

#### How I did it
* Integrated Packet Trimming interface into `config` and `show` CLI root

#### How to verify it
1. Run Packet Trimming CLI UTs

#### Previous command output (if the output of a command-line utility has changed)
* N/A

#### New command output (if the output of a command-line utility has changed)
* N/A

#### A picture of a cute animal (not mandatory but encouraged)
```
      .---.        .-----------
     /     \  __  /    ------
    / /     \(  )/    -----
   //////   ' \/ `   ---
  //// / // :    : ---
 // /   /  /`    '--
//          //..\\
       ====UU====UU====
           '//||\\`
             ''``
```

Author: mssonicbld

config/main.py

@@ -7456,6 +7456,7 @@ def ecn(profile, rmax, rmin, ymax, ymin, gmax, gmin, rdrop, ydrop, gdrop, verbos
 @click.option('-p', metavar='<profile_name>', type=str, required=True, help="Profile name")
 @click.option('-a', metavar='<alpha>', type=click.IntRange(-8,8), help="Set alpha for profile type dynamic")
 @click.option('-s', metavar='<staticth>', type=click.IntRange(min=0), help="Set staticth for profile type static")
+@click.option('-t', type=click.Choice(["on", "off"]), help="Set packet trimming eligibility")
 @click.option('--verbose', '-vv', is_flag=True, help="Enable verbose output")
 @click.option('--namespace',
               '-n',
@@ -7465,12 +7466,14 @@ def ecn(profile, rmax, rmin, ymax, ymin, gmax, gmin, rdrop, ydrop, gdrop, verbos
               show_default=True,
               help='Namespace name or all',
               callback=multi_asic_util.multi_asic_namespace_validation_callback)
-def mmu(p, a, s, namespace, verbose):
+def mmu(p, a, s, t, namespace, verbose):
     """mmuconfig configuration tasks"""
     log.log_info("'mmuconfig -p {}' executing...".format(p))
     command = ['mmuconfig', '-p', str(p)]
     if a is not None: command += ['-a', str(a)]
     if s is not None: command += ['-s', str(s)]
+    if t is not None:
+        command += ['-t', str(t)]
     if namespace is not None:
         command += ['-n', str(namespace)]
     if verbose:

config/plugins/sonic-trimming.py

@@ -0,0 +1,228 @@
+"""
+This CLI plugin was auto-generated by using 'sonic-cli-gen' utility
+"""
+
+import click
+import utilities_common.cli as clicommon
+
+from sonic_py_common import logger
+from utilities_common.switch_trimming import (
+    CFG_SWITCH_TRIMMING,
+    STATE_SWITCH_CAPABILITY,
+    STATE_CAP_TRIMMING_CAPABLE_KEY,
+    STATE_CAP_QUEUE_MODE_KEY,
+    STATE_CAP_QUEUE_MODE_DYNAMIC,
+    STATE_CAP_QUEUE_MODE_STATIC,
+    CFG_TRIM_QUEUE_INDEX_DYNAMIC,
+    CFG_TRIM_KEY,
+    STATE_CAP_KEY,
+    UINT32_MAX,
+    UINT8_MAX,
+    SYSLOG_IDENTIFIER,
+    get_db,
+    to_str,
+)
+
+
+log = logger.Logger(SYSLOG_IDENTIFIER)
+log.set_min_log_priority_info()
+
+
+#
+# Validators ----------------------------------------------------------------------------------------------------------
+#
+
+
+class SizeTypeValidator(click.ParamType):
+    """ Size option validator """
+    name = "integer"
+
+    def convert(self, value, param, ctx):
+        click.IntRange(0, UINT32_MAX).convert(value, param, ctx)
+        return value
+
+
+class DscpTypeValidator(click.ParamType):
+    """ Dscp option validator """
+    name = "integer"
+
+    def convert(self, value, param, ctx):
+        click.IntRange(0, UINT8_MAX).convert(value, param, ctx)
+        return value
+
+
+class QueueTypeValidator(click.ParamType):
+    """ Queue index option validator """
+    name = "text"
+
+    def get_metavar(self, param):
+        db = get_db(click.get_current_context())
+
+        entry = db.get_all(db.STATE_DB, "{}|{}".format(STATE_SWITCH_CAPABILITY, STATE_CAP_KEY))
+        entry.setdefault(STATE_CAP_QUEUE_MODE_KEY, "N/A")
+
+        cap_list = entry[STATE_CAP_QUEUE_MODE_KEY].split(',')
+
+        if cap_list.count(STATE_CAP_QUEUE_MODE_DYNAMIC) == len(cap_list):
+            return "dynamic"
+        elif cap_list.count(STATE_CAP_QUEUE_MODE_STATIC) == len(cap_list):
+            return "INTEGER"
+
+        return "[INTEGER|dynamic]"
+
+    def convert(self, value, param, ctx):
+        db = get_db(ctx)
+
+        entry = db.get_all(db.STATE_DB, "{}|{}".format(STATE_SWITCH_CAPABILITY, STATE_CAP_KEY))
+
+        entry.setdefault(STATE_CAP_TRIMMING_CAPABLE_KEY, "false")
+        entry.setdefault(STATE_CAP_QUEUE_MODE_KEY, "N/A")
+
+        if entry[STATE_CAP_TRIMMING_CAPABLE_KEY] == "false":
+            raise click.UsageError("Failed to configure {}: operation is not supported".format(
+                param.get_error_hint(ctx)), ctx
+            )
+
+        if not entry[STATE_CAP_QUEUE_MODE_KEY]:
+            raise click.UsageError("Failed to configure {}: no queue resolution mode capabilities".format(
+                param.get_error_hint(ctx)), ctx
+            )
+
+        verify_cap = True
+
+        if entry[STATE_CAP_QUEUE_MODE_KEY] == "N/A":
+            verify_cap = False
+
+        cap_list = entry[STATE_CAP_QUEUE_MODE_KEY].split(',')
+
+        if value == CFG_TRIM_QUEUE_INDEX_DYNAMIC:
+            if verify_cap and (STATE_CAP_QUEUE_MODE_DYNAMIC not in cap_list):
+                self.fail("dynamic queue resolution mode is not supported", param, ctx)
+        else:
+            if verify_cap and (STATE_CAP_QUEUE_MODE_STATIC not in cap_list):
+                self.fail("static queue resolution mode is not supported", param, ctx)
+
+            click.IntRange(0, UINT8_MAX).convert(value, param, ctx)
+
+        return value
+
+
+#
+# DB interface --------------------------------------------------------------------------------------------------------
+#
+
+
+def update_entry_validated(db, table, key, data, create_if_not_exists=False):
+    """ Update entry in table and validate configuration.
+    If attribute value in data is None, the attribute is deleted.
+
+    Args:
+        db (swsscommon.ConfigDBConnector): Config DB connector object.
+        table (str): Table name to add new entry to.
+        key (Union[str, Tuple]): Key name in the table.
+        data (Dict): Entry data.
+        create_if_not_exists (bool):
+            In case entry does not exists already a new entry
+            is not created if this flag is set to False and
+            creates a new entry if flag is set to True.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    cfg = db.get_config()
+    cfg.setdefault(table, {})
+
+    if not data:
+        raise click.ClickException(f"No field/values to update {key}")
+
+    if create_if_not_exists:
+        cfg[table].setdefault(key, {})
+
+    if key not in cfg[table]:
+        raise click.ClickException(f"{key} does not exist")
+
+    entry_changed = False
+    for attr, value in data.items():
+        if value == cfg[table][key].get(attr):
+            continue
+        if value is not None:
+            cfg[table][key][attr] = value
+            entry_changed = True
+
+    if not entry_changed:
+        return
+
+    db.set_entry(table, key, cfg[table][key])
+
+
+#
+# CLI -----------------------------------------------------------------------------------------------------------------
+#
+
+
+@click.group(
+    name="switch-trimming",
+    cls=clicommon.AliasedGroup
+)
+def SWITCH_TRIMMING():
+    """ Configure switch trimming feature """
+
+    pass
+
+
+@SWITCH_TRIMMING.command(
+    name="global"
+)
+@click.option(
+    "-s", "--size", "size",
+    help="Configures size (in bytes) to trim eligible packet",
+    type=SizeTypeValidator(),
+)
+@click.option(
+    "-d", "--dscp", "dscp",
+    help="Configures DSCP value assigned to a packet after trimming",
+    type=DscpTypeValidator(),
+)
+@click.option(
+    "-q", "--queue", "queue",
+    help="Configures queue index to use for transmission of a packet after trimming",
+    type=QueueTypeValidator(),
+)
+@clicommon.pass_db
+@click.pass_context
+def SWITCH_TRIMMING_GLOBAL(ctx, db, size, dscp, queue):
+    """ Configure switch trimming global """
+
+    if not (size or dscp or queue):
+        raise click.UsageError("Failed to configure switch trimming global: no options are provided", ctx)
+
+    table = CFG_SWITCH_TRIMMING
+    key = CFG_TRIM_KEY
+
+    data = {
+        "size": size,
+        "dscp_value": dscp,
+        "queue_index": queue,
+    }
+
+    try:
+        update_entry_validated(db.cfgdb, table, key, data, create_if_not_exists=True)
+        log.log_notice("Configured switch trimming global: {}".format(to_str(data)))
+    except Exception as e:
+        log.log_error("Failed to configure switch trimming global: {}".format(str(e)))
+        ctx.fail(str(e))
+
+
+def register(cli):
+    """ Register new CLI nodes in root CLI.
+
+    Args:
+        cli: Root CLI node.
+    Raises:
+        Exception: when root CLI already has a command
+                   we are trying to register.
+    """
+    cli_node = SWITCH_TRIMMING
+    if cli_node.name in cli.commands:
+        raise Exception(f"{cli_node.name} already exists in CLI")
+    cli.add_command(SWITCH_TRIMMING)