cli.py

import contextlib
from datetime import datetime
from functools import partial
import json
import socket

import click
import jsonschema
from lxml import etree

from brian_polling_manager.interface_stats import config, brian, errors
from brian_polling_manager.interface_stats.vendors import juniper
from brian_polling_manager import influx, inventory


import logging.config
import os

LOGGING_DEFAULT_CONFIG = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'simple': {
            'format': '%(asctime)s - %(name)s '
                      '(%(lineno)d) - %(levelname)s - %(message)s'
        }
    },

    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
            'level': 'DEBUG',
            'formatter': 'simple',
            'stream': 'ext://sys.stdout'
        },
    },

    'loggers': {
        'brian_polling_manager': {
            'level': 'DEBUG',
            'handlers': ['console'],
            'propagate': False
        }
    },

    'root': {
        'level': 'INFO',
        'handlers': ['console']
    }
}


def setup_logging():
    """
    set up logging using the configured filename

    if LOGGING_CONFIG is defined in the environment, use this for
    the filename, otherwise use LOGGING_DEFAULT_CONFIG
    """
    logging_config = LOGGING_DEFAULT_CONFIG
    if 'LOGGING_CONFIG' in os.environ:
        filename = os.environ['LOGGING_CONFIG']
        with open(filename) as f:
            logging_config = json.loads(f.read())

    # # TODO: this mac workaround should be removed ...
    # import platform
    # if platform.system() == 'Darwin':
    #     logging_config['handlers']['syslog_handler']['address'] \
    #         = '/var/run/syslog'

    logging.config.dictConfig(logging_config)


def ctr2point(measurement, timestamp, counters):
    """
    :param measurement: the measurement where the point will be written
    :param counters: either a BRIAN_COUNTER_DICT_SCHEMA or
        ERROR_COUNTER_DICT_SCHEMA object
    :return: a brian_polling_manager.influx.INFLUX_POINT object
    """
    def _is_tag(key_name):
        return key_name == 'hostname' or key_name == 'interface_name'

    fields = dict([_k, _v] for _k, _v in counters.items() if not _is_tag(_k))
    tags = dict([_k, _v] for _k, _v in counters.items() if _is_tag(_k))
    return {
        'time':  timestamp.strftime('%Y-%m-%dT%H:%M:%SZ'),
        'measurement': measurement,
        'tags': tags,
        'fields': fields,
    }


def _validate_config(_unused_ctx, _unused_param, file):
    try:
        return config.load(file)
    except json.JSONDecodeError:
        raise click.BadParameter('config file is not valid json')
    except jsonschema.ValidationError as e:
        raise click.BadParameter(e)


def _validate_hostname(_unused_ctx, _unused_param, hostname):
    try:
        socket.gethostbyname(hostname)
    except socket.error:
        raise click.BadParameter(f'{hostname} is not resolveable')
    return hostname


def _brian_points(router_fqdn, netconf_doc, timestamp, measurement_name):
    """
    returns an interable of points that can be written to influxdb

    :param router_fqdn: 'hostname' tag to be set in the generated points
    :param netconf_doc: a valid loaded netconf doc
    :param timestamp: timestamp to put in the generated points
    :param measurement_name: measurement name to put in the generated points
    :return:
    """
    _ctr2point = partial(ctr2point, measurement_name, timestamp)

    interfaces = juniper.physical_interface_counters(netconf_doc)
    counters = brian.counters(router_fqdn=router_fqdn, interface_counters=interfaces)
    yield from map(_ctr2point, counters)

    interfaces = juniper.logical_interface_counters(netconf_doc)
    counters = brian.counters(router_fqdn=router_fqdn, interface_counters=interfaces)
    yield from map(_ctr2point, counters)


def _error_points(router_fqdn, netconf_doc, timestamp, measurement_name):
    """
    returns an interable of points that can be written to influxdb

    :param router_fqdn: 'hostname' tag to be set in the generated points
    :param netconf_doc: a valid loaded netconf doc
    :param timestamp: timestamp to put in the generated points
    :param measurement_name: measurement name to put in the generated points
    :return:
    """
    _ctr2point = partial(ctr2point, measurement_name, timestamp)

    interfaces = juniper.physical_interface_counters(netconf_doc)
    counters = errors.counters(router_fqdn=router_fqdn, interface_counters=interfaces)
    yield from map(_ctr2point, counters)

    interfaces = juniper.logical_interface_counters(netconf_doc)
    counters = errors.counters(router_fqdn=router_fqdn, interface_counters=interfaces)
    yield from map(_ctr2point, counters)


def _main(router_fqdn: str, app_config_params: dict):
    """
    callable entry point, without click - for testing

    loads the netconf 'show interfaces' info for the router fqdn,
    then uses this to generate brian and error points and writes them to influxdb

    note: the optional inventory param is only used to validate the hostname

    :param router_fqdn:
    :param app_config_params:
    :return:
    """

    if 'inventory' in app_config_params:
        all_routers = {_ifc['router'] for _ifc in inventory.load_interfaces()}
        if router_fqdn not in all_routers:
            raise ValueError(f'{router_fqdn} must be one of: {all_routers}')

    setup_logging()

    netconf_doc = juniper.get_interface_info_ncrpc(
        router_fqdn,
        ssh_config=app_config_params['ssh-config'])
    netconf_timestamp = datetime.now()

    influx_params = app_config_params['influx']['brian-counters']
    points = _brian_points(
        router_fqdn=router_fqdn,
        netconf_doc=netconf_doc,
        timestamp=netconf_timestamp,
        measurement_name=influx_params['measurement'])

    with contextlib.closing(influx.influx_client(influx_params)) as client:
        client.write_points(points)

    influx_params = app_config_params['influx']['error-counters']
    points = _error_points(
        router_fqdn=router_fqdn,
        netconf_doc=netconf_doc,
        timestamp=netconf_timestamp,
        measurement_name=influx_params['measurement'])

    with contextlib.closing(influx.influx_client(influx_params)) as client:
        client.write_points(points)


@click.command()
@click.option(
    '--config', 'app_config_params',
    required=True,
    type=click.File('r'),
    help='config filename',
    callback=_validate_config)
@click.option(
    '--router', 'router_fqdn',
    required=True,
    type=click.STRING,
    help='router fqdn',
    callback=_validate_hostname)
@click.option(
    '--netconf-only/--no-netconf-only', 'netconf_only',
    default=False,
    type=click.BOOL,
    help='just run the netconf query and output the simplified xml, then exit')
def main(router_fqdn: str, app_config_params: dict, netconf_only: bool):

    # this is expected to be called only when debugging config/setup
    if netconf_only:
        _doc = juniper.get_interface_info_ncrpc(
            router_fqdn,
            ssh_config=app_config_params['ssh-config'])
        print(etree.tostring(_doc, pretty_print=True).decode('utf-8'))
        return

    # normal flow ...
    _main(router_fqdn, app_config_params)


if __name__ == '__main__':
    main()