#!/usr/bin/python
# -*- coding: utf-8 -*-
"""
This is the module for quering the Policy service.
This module exports classes and methods for interacting with the designated
`Pacifica Policy <https://github.com/pacifica/pacifica-policy>`_ server.
"""
from __future__ import absolute_import
import json
import logging
from collections import namedtuple
from .mjson import generate_namedtuple_encoder, generate_namedtuple_decoder
from .metadata import metadata_encode
from ..common import CommonBase
LOGGER = logging.getLogger(__name__)
QUERY_KEYS = [
'user',
'columns',
'from_table',
'where'
]
_PolicyQueryData = namedtuple('PolicyQueryData', QUERY_KEYS)
# Set the defaults to None for these attributes
_PolicyQueryData.__new__.__defaults__ = (None,) * len(_PolicyQueryData._fields)
[docs]class PolicyQueryData(_PolicyQueryData):
"""
Policy query data elements for policy query requests.
This class is a sub-class of the `collections.namedtuple` class. This class is used directly against the
`Pacifica Uploader Policy <https://github.com/pacifica/pacifica-policy/tree/master/pacifica/policy/uploader/>`_
endpoint.
"""
[docs]class PolicyQuery(CommonBase):
"""
Handle quering the policy server.
Instances of this class represent queries to the designated
`Pacifica Policy <https://github.com/pacifica/pacifica-policy>`_ server.
"""
pq_data = None
user_id = None
_proto = None
_addr = None
_port = None
_uploader_path = None
_ingest_path = None
_uploader_url = None
_ingest_url = None
_auth = None
[docs] def set_user(self, user):
"""Set the user for the current PolicyQuery."""
try:
self.user_id = int(user)
except ValueError:
id_check = PolicyQuery(
user=-1,
columns=['_id'],
from_table='users',
where={'network_id': user},
auth=self._auth
)
self.user_id = id_check.get_results()[0]['_id']
[docs] def get_user(self):
"""Get the user id."""
return self.user_id
[docs] def _set_url_from_parts(self):
"""Set the url from the parts in self."""
for url_part in ['uploader', 'ingest']:
if not getattr(self, '_{}_url'.format(url_part)):
url_str = '{}://{}:{}{}'.format(
self._proto,
self._addr,
self._port,
getattr(self, '_{}_path'.format(url_part))
)
setattr(self, '_{}_url'.format(url_part), url_str)
[docs] def __init__(self, user, *args, **kwargs):
"""
Set the policy server url and define any data for the query.
The HTTP end-point for the policy server is
automatically pulled either from the system environment or from the keyword
arguments, `**kwargs`.
"""
self._server_url(
[
('proto', 'http'),
('port', 8181),
('addr', '127.0.0.1'),
('uploader_path', '/uploader'),
('ingest_path', '/ingest'),
('uploader_url', None),
('ingest_url', None)
],
'POLICY',
kwargs
)
self._set_url_from_parts()
self._setup_requests_session()
self._auth = kwargs.pop('auth', {})
LOGGER.debug('Policy URL %s auth %s', self._uploader_url, self._auth)
# global sential value for userid
if user != -1:
self.set_user(user)
self.pq_data = PolicyQueryData(
user=self.get_user(), *args, **kwargs)
else:
self.pq_data = PolicyQueryData(user=-1, **kwargs)
[docs] def tojson(self):
"""Export self to json."""
return json.dumps(self.pq_data, cls=PolicyQueryDataEncoder)
[docs] @staticmethod
def fromjson(json_str):
"""Import json string to self."""
pq_data = json.loads(json_str, cls=PolicyQueryDataDecoder)
pq_dict = pq_data._asdict()
user = pq_dict.pop('user', -1)
return PolicyQuery(user, **pq_dict)
[docs] def get_results(self):
"""
Get results from the Policy server for the query.
This method returns a JSON object that is the result set for a query to the
`Pacifica Policy <https://github.com/pacifica/pacifica-policy>`_ server, i.e., the
entities that match the criteria that is represented by the associated instance
of the ``pacifica.uploader.metadata.PolicyQuery.PolicyQueryData`` class.
"""
headers = {'content-type': 'application/json'}
LOGGER.debug('Policy Query Uploader %s', self.tojson())
reply = self.session.post(
self._uploader_url, headers=headers, data=self.tojson(), **self._auth)
LOGGER.debug('Policy Result Uploader %s', reply.content)
return reply.json()
#####################################################################
# The from key in the json data is for the policy server.
# It's also a keyword in python so it needs to be handled correctly
#####################################################################
[docs]def _mangle_encode(obj):
"""Move the from_table to just from."""
obj['from'] = obj.pop('from_table')
[docs]def _mangle_decode(**json_data):
"""Mangle the decode of the policy query object."""
json_data['from_table'] = json_data.pop('from')
return PolicyQueryData(**json_data)
PolicyQueryDataEncoder = generate_namedtuple_encoder(
PolicyQueryData, _mangle_encode)
PolicyQueryDataDecoder = generate_namedtuple_decoder(_mangle_decode)