[nvgre] Added auto-generated CLI plugins and test for NVGRE Tunnel fe…

…ature (sonic-net#1915)

- What I did
Added a click CLI plugins for NVGRE Tunnel feature

- How I did it
The CLI plugins were auto-generated (by using the sonic-cli-gen) for the show and config CLI groups.

- How to verify it
Added UT.

Signed-off-by: Vadym Hlushko <vadymh@nvidia.com>

config/plugins/nvgre_tunnel.py

@@ -0,0 +1,349 @@
+"""
+Autogenerated config CLI plugin for NVGRE Tunnel feature.
+"""
+
+import copy
+import click
+import utilities_common.cli as clicommon
+import utilities_common.general as general
+from config import config_mgmt
+
+
+# Load sonic-cfggen from source since /usr/local/bin/sonic-cfggen does not have .py extension.
+sonic_cfggen = general.load_module_from_source('sonic_cfggen', '/usr/local/bin/sonic-cfggen')
+
+
+def exit_with_error(*args, **kwargs):
+    """ Print a message with click.secho and abort CLI.
+
+    Args:
+        args: Positional arguments to pass to click.secho
+        kwargs: Keyword arguments to pass to click.secho
+    """
+
+    click.secho(*args, **kwargs)
+    raise click.Abort()
+
+
+def validate_config_or_raise(cfg):
+    """ Validate config db data using ConfigMgmt.
+
+    Args:
+        cfg (Dict): Config DB data to validate.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    try:
+        cfg = sonic_cfggen.FormatConverter.to_serialized(copy.deepcopy(cfg))
+        config_mgmt.ConfigMgmt().loadData(cfg)
+    except Exception as err:
+        raise Exception('Failed to validate configuration: {}'.format(err))
+
+
+def add_entry_validated(db, table, key, data):
+    """ Add new entry in table and validate configuration.
+
+    Args:
+        db (swsscommon.ConfigDBConnector): Config DB connector obect.
+        table (str): Table name to add new entry to.
+        key (Union[str, Tuple]): Key name in the table.
+        data (Dict): Entry data.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    cfg = db.get_config()
+    cfg.setdefault(table, {})
+    if key in cfg[table]:
+        raise Exception(f"{key} already exists")
+
+    cfg[table][key] = data
+
+    validate_config_or_raise(cfg)
+    db.set_entry(table, key, data)
+
+
+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 obect.
+        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 Exception(f"No field/values to update {key}")
+
+    if create_if_not_exists:
+        cfg[table].setdefault(key, {})
+
+    if key not in cfg[table]:
+        raise Exception(f"{key} does not exist")
+
+    entry_changed = False
+    for attr, value in data.items():
+        if value == cfg[table][key][attr]:
+            continue
+        entry_changed = True
+        if value is None:
+            cfg[table][key].pop(attr, None)
+        else:
+            cfg[table][key][attr] = value
+
+    if not entry_changed:
+        return
+
+    validate_config_or_raise(cfg)
+    db.set_entry(table, key, cfg[table][key])
+
+
+def del_entry_validated(db, table, key):
+    """ Delete entry in table and validate configuration.
+
+    Args:
+        db (swsscommon.ConfigDBConnector): Config DB connector obect.
+        table (str): Table name to add new entry to.
+        key (Union[str, Tuple]): Key name in the table.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    cfg = db.get_config()
+    cfg.setdefault(table, {})
+    if key not in cfg[table]:
+        raise Exception(f"{key} does not exist")
+
+    cfg[table].pop(key)
+
+    validate_config_or_raise(cfg)
+    db.set_entry(table, key, None)
+
+
+def add_list_entry_validated(db, table, key, attr, data):
+    """ Add new entry into list in table and validate configuration.
+
+    Args:
+        db (swsscommon.ConfigDBConnector): Config DB connector obect.
+        table (str): Table name to add data to.
+        key (Union[str, Tuple]): Key name in the table.
+        attr (str): Attribute name which represents a list the data needs to be added to.
+        data (List): Data list to add to config DB.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    cfg = db.get_config()
+    cfg.setdefault(table, {})
+    if key not in cfg[table]:
+        raise Exception(f"{key} does not exist")
+    cfg[table][key].setdefault(attr, [])
+    for entry in data:
+        if entry in cfg[table][key][attr]:
+            raise Exception(f"{entry} already exists")
+        cfg[table][key][attr].append(entry)
+
+    validate_config_or_raise(cfg)
+    db.set_entry(table, key, cfg[table][key])
+
+
+def del_list_entry_validated(db, table, key, attr, data):
+    """ Delete entry from list in table and validate configuration.
+
+    Args:
+        db (swsscommon.ConfigDBConnector): Config DB connector obect.
+        table (str): Table name to remove data from.
+        key (Union[str, Tuple]): Key name in the table.
+        attr (str): Attribute name which represents a list the data needs to be removed from.
+        data (Dict): Data list to remove from config DB.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    cfg = db.get_config()
+    cfg.setdefault(table, {})
+    if key not in cfg[table]:
+        raise Exception(f"{key} does not exist")
+    cfg[table][key].setdefault(attr, [])
+    for entry in data:
+        if entry not in cfg[table][key][attr]:
+            raise Exception(f"{entry} does not exist")
+        cfg[table][key][attr].remove(entry)
+    if not cfg[table][key][attr]:
+        cfg[table][key].pop(attr)
+
+    validate_config_or_raise(cfg)
+    db.set_entry(table, key, cfg[table][key])
+
+
+def clear_list_entry_validated(db, table, key, attr):
+    """ Clear list in object and validate configuration.
+
+    Args:
+        db (swsscommon.ConfigDBConnector): Config DB connector obect.
+        table (str): Table name to remove the list attribute from.
+        key (Union[str, Tuple]): Key name in the table.
+        attr (str): Attribute name which represents a list that needs to be removed.
+    Raises:
+        Exception: when cfg does not satisfy YANG schema.
+    """
+
+    update_entry_validated(db, table, key, {attr: None})
+
+
+@click.group(
+    name="nvgre-tunnel",
+    cls=clicommon.AliasedGroup)
+def NVGRE_TUNNEL():
+    """ NVGRE_TUNNEL part of config_db.json """
+
+    pass
+
+
+@NVGRE_TUNNEL.command(name="add")
+@click.argument(
+    "tunnel-name",
+    nargs=1,
+    required=True,
+)
+@click.option(
+    "--src-ip",
+    required=True,
+    help="Source IP address[mandatory]",
+)
+@clicommon.pass_db
+def NVGRE_TUNNEL_add(db, tunnel_name, src_ip):
+    """ Add object in NVGRE_TUNNEL. """
+
+    table = "NVGRE_TUNNEL"
+    key = tunnel_name
+    data = {}
+    if src_ip is not None:
+        data["src_ip"] = src_ip
+
+    try:
+        add_entry_validated(db.cfgdb, table, key, data)
+    except Exception as err:
+        exit_with_error(f"Error: {err}", fg="red")
+
+
+@NVGRE_TUNNEL.command(name="delete")
+@click.argument(
+    "tunnel-name",
+    nargs=1,
+    required=True,
+)
+@clicommon.pass_db
+def NVGRE_TUNNEL_delete(db, tunnel_name):
+    """ Delete object in NVGRE_TUNNEL. """
+
+    table = "NVGRE_TUNNEL"
+    key = tunnel_name
+    try:
+        del_entry_validated(db.cfgdb, table, key)
+    except Exception as err:
+        exit_with_error(f"Error: {err}", fg="red")
+
+
+@click.group(
+    name="nvgre-tunnel-map",
+    cls=clicommon.AliasedGroup)
+def NVGRE_TUNNEL_MAP():
+    """ NVGRE_TUNNEL_MAP part of config_db.json """
+
+    pass
+
+
+@NVGRE_TUNNEL_MAP.command(name="add")
+@click.argument(
+    "tunnel-name",
+    nargs=1,
+    required=True,
+)
+@click.argument(
+    "tunnel-map-name",
+    nargs=1,
+    required=True,
+)
+
+@click.option(
+    "--vlan-id",
+    required=True,
+    help="VLAN identifier[mandatory]",
+)
+@click.option(
+    "--vsid",
+    required=True,
+    help="Virtual Subnet Identifier[mandatory]",
+)
+@clicommon.pass_db
+def NVGRE_TUNNEL_MAP_add(db, tunnel_name, tunnel_map_name, vlan_id, vsid):
+    """ Add object in NVGRE_TUNNEL_MAP. """
+
+    table = "NVGRE_TUNNEL_MAP"
+    key = tunnel_name, tunnel_map_name
+    data = {}
+    if vlan_id is not None:
+        data["vlan_id"] = vlan_id
+    if vsid is not None:
+        data["vsid"] = vsid
+
+    try:
+        add_entry_validated(db.cfgdb, table, key, data)
+    except Exception as err:
+        exit_with_error(f"Error: {err}", fg="red")
+
+
+@NVGRE_TUNNEL_MAP.command(name="delete")
+@click.argument(
+    "tunnel-name",
+    nargs=1,
+    required=True,
+)
+@click.argument(
+    "tunnel-map-name",
+    nargs=1,
+    required=True,
+)
+@clicommon.pass_db
+def NVGRE_TUNNEL_MAP_delete(db, tunnel_name, tunnel_map_name):
+    """ Delete object in NVGRE_TUNNEL_MAP. """
+
+    table = "NVGRE_TUNNEL_MAP"
+    key = tunnel_name, tunnel_map_name
+    try:
+        del_entry_validated(db.cfgdb, table, key)
+    except Exception as err:
+        exit_with_error(f"Error: {err}", fg="red")
+
+
+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 = NVGRE_TUNNEL
+    if cli_node.name in cli.commands:
+        raise Exception(f"{cli_node.name} already exists in CLI")
+    cli.add_command(NVGRE_TUNNEL)
+    cli_node = NVGRE_TUNNEL_MAP
+    if cli_node.name in cli.commands:
+        raise Exception(f"{cli_node.name} already exists in CLI")
+    cli.add_command(NVGRE_TUNNEL_MAP)
+