Extra links supported for operators coming from third-party packages:

airflow.serialization.serialized_objects.BUILTIN_OPERATOR_EXTRA_LINKS

airflow/cli/cli_parser.py
ActionCommand(
        name='reset',
        help="Burn down and rebuild the metadata database",
        func=lazy_load_command('airflow.cli.commands.db_command.resetdb'),
        args=(ARG_YES,),
    ),
    ActionCommand(
        name='upgrade',
        help="Upgrade the metadata database to latest version",
        func=lazy_load_command('airflow.cli.commands.db_command.upgradedb'),
        args=(),
    ),
    ActionCommand(
        name='shell',
        help="Runs a shell to access the database",
        func=lazy_load_command('airflow.cli.commands.db_command.shell'),
        args=(),
    ),
    ActionCommand(
        name='check',
        help="Check if the database can be reached",
        func=lazy_load_command('airflow.cli.commands.db_command.check'),
        args=(),
    ),
)
CONNECTIONS_COMMANDS = (
    ActionCommand(
        name='get',
        help='Get a connection',
        func=lazy_load_command('airflow.cli.commands.connection_command.connections_get'),