Drop python2 support
This mostly consists in removing the dependency on "six" and updating
the code to use only Python3 idioms.
Notice that we previously used TemporaryDirectory from
cubicweb.devtools.testlib for compatibility with Python2. We now
directly import it from tempfile.
# copyright 2010-2016 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""datafeed sources: copy data from an external data stream into the system
database
"""
from warnings import warn
from io import BytesIO
from os.path import exists
from datetime import datetime, timedelta
from functools import partial
from http.cookiejar import CookieJar
from urllib.parse import urlparse
from urllib.request import Request, build_opener, HTTPCookieProcessor
from urllib.error import HTTPError
from pytz import utc
from lxml import etree
from cubicweb import ObjectNotFound, ValidationError, SourceException, _
from cubicweb.server.sources import AbstractSource
from cubicweb.appobject import AppObject
class DataFeedSource(AbstractSource):
use_cwuri_as_url = True
options = (
('synchronize',
{'type' : 'yn',
'default': True,
'help': ('Is the repository responsible to automatically import '
'content from this source? '
'You should say yes unless you don\'t want this behaviour '
'or if you use a multiple repositories setup, in which '
'case you should say yes on one repository, no on others.'),
'group': 'datafeed-source', 'level': 2,
}),
('synchronization-interval',
{'type' : 'time',
'default': '5min',
'help': ('Interval in seconds between synchronization with the '
'external source (default to 5 minutes, must be >= 1 min).'),
'group': 'datafeed-source', 'level': 2,
}),
('max-lock-lifetime',
{'type' : 'time',
'default': '1h',
'help': ('Maximum time allowed for a synchronization to be run. '
'Exceeded that time, the synchronization will be considered '
'as having failed and not properly released the lock, hence '
'it won\'t be considered'),
'group': 'datafeed-source', 'level': 2,
}),
('delete-entities',
{'type' : 'yn',
'default': False,
'help': ('Should already imported entities not found anymore on the '
'external source be deleted? Handling of this parameter '
"will depend on source's parser."),
'group': 'datafeed-source', 'level': 2,
}),
('logs-lifetime',
{'type': 'time',
'default': '10d',
'help': ('Time before logs from datafeed imports are deleted.'),
'group': 'datafeed-source', 'level': 2,
}),
('http-timeout',
{'type': 'time',
'default': '1min',
'help': ('Timeout of HTTP GET requests, when synchronizing a source.'),
'group': 'datafeed-source', 'level': 2,
}),
('use-cwuri-as-url',
{'type': 'yn',
'default': None, # explicitly unset
'help': ('Use cwuri (i.e. external URL) for link to the entity '
'instead of its local URL.'),
'group': 'datafeed-source', 'level': 1,
}),
)
def check_config(self, source_entity):
"""check configuration of source entity"""
typed_config = super(DataFeedSource, self).check_config(source_entity)
if typed_config['synchronization-interval'] < 60:
msg = _('synchronization-interval must be greater than 1 minute')
raise ValidationError(source_entity.eid, {'config': msg})
return typed_config
def init(self, source_entity):
super(DataFeedSource, self).init(source_entity)
self.parser_id = source_entity.parser
self.latest_retrieval = source_entity.latest_retrieval
typed_config = self.config
self.synchro_interval = timedelta(seconds=typed_config['synchronization-interval'])
self.max_lock_lifetime = timedelta(seconds=typed_config['max-lock-lifetime'])
self.http_timeout = typed_config['http-timeout']
# if typed_config['use-cwuri-as-url'] is set, we have to update
# use_cwuri_as_url attribute and public configuration dictionary
# accordingly
if typed_config['use-cwuri-as-url'] is not None:
self.use_cwuri_as_url = typed_config['use-cwuri-as-url']
self.public_config['use-cwuri-as-url'] = self.use_cwuri_as_url
def _get_parser(self, cnx, **kwargs):
if self.parser_id is None:
self.warning('No parser defined on source %r', self)
raise ObjectNotFound()
return self.repo.vreg['parsers'].select(
self.parser_id, cnx, source=self, **kwargs)
def fresh(self):
if self.latest_retrieval is None:
return False
return datetime.now(tz=utc) < (self.latest_retrieval + self.synchro_interval)
def update_latest_retrieval(self, cnx):
self.latest_retrieval = datetime.now(tz=utc)
cnx.execute('SET X latest_retrieval %(date)s WHERE X eid %(x)s',
{'x': self.eid, 'date': self.latest_retrieval})
cnx.commit()
def acquire_synchronization_lock(self, cnx):
# XXX race condition until WHERE of SET queries is executed using
# 'SELECT FOR UPDATE'
now = datetime.now(tz=utc)
maxdt = now - self.max_lock_lifetime
if not cnx.execute(
'SET X in_synchronization %(now)s WHERE X eid %(x)s, '
'X in_synchronization NULL OR X in_synchronization < %(maxdt)s',
{'x': self.eid, 'now': now, 'maxdt': maxdt}):
cnx.commit()
raise SourceException("a concurrent synchronization is already running")
cnx.commit()
def release_synchronization_lock(self, cnx):
cnx.execute('SET X in_synchronization NULL WHERE X eid %(x)s',
{'x': self.eid})
cnx.commit()
def pull_data(self, cnx, force=False, raise_on_error=False, sync=True, **kwargs):
"""Launch synchronization of the source if needed.
If `sync` is false, the method return immediatly a dictionnary containing the import log's
eid, and the actual synchronization is done asynchronously. If `sync` is True, return some
imports statistics (e.g. number of created and updated entities).
This method is responsible to handle commit/rollback on the given connection.
"""
if not force and self.fresh():
return {}
try:
self.acquire_synchronization_lock(cnx)
except SourceException as exc:
if force:
raise
self.error(str(exc))
return {}
try:
if kwargs.get('async') is not None:
warn('[3.27] `async` is reserved keyword in py3.7 use `sync` param instead',
DeprecationWarning)
sync = not kwargs['async']
if sync:
return self._pull_data(cnx, force, raise_on_error)
else:
return self._async_pull_data(cnx, force, raise_on_error)
finally:
cnx.rollback() # rollback first in case there is some dirty transaction remaining
self.release_synchronization_lock(cnx)
def _async_pull_data(self, cnx, force, raise_on_error):
import_log = cnx.create_entity('CWDataImport', cw_import_of=self)
cnx.commit() # commit the import log creation before starting the synchronize task
def _synchronize_source(repo, source_eid, import_log_eid):
with repo.internal_cnx() as cnx:
source = repo.source_by_eid(source_eid)
source._pull_data(cnx, force, raise_on_error, import_log_eid=import_log_eid)
sync = partial(_synchronize_source, cnx.repo, self.eid, import_log.eid)
cnx.repo.threaded_task(sync)
return {'import_log_eid': import_log.eid}
def _pull_data(self, cnx, force=False, raise_on_error=False, import_log_eid=None):
importlog = self.init_import_log(cnx, import_log_eid)
try:
parser = self._get_parser(cnx, import_log=importlog)
except ObjectNotFound:
msg = 'failed to load parser for %s'
importlog.record_error(msg % ('source "%s"' % self.uri))
self.error(msg, self)
stats = {}
else:
if parser.process_urls(self.urls, raise_on_error):
self.warning("some error occurred, don't attempt to delete entities")
stats = parser.stats
self.update_latest_retrieval(cnx)
if stats.get('created'):
importlog.record_info('added %s entities' % len(stats['created']))
if stats.get('updated'):
importlog.record_info('updated %s entities' % len(stats['updated']))
importlog.write_log(cnx, end_timestamp=self.latest_retrieval)
cnx.commit()
return stats
def init_import_log(self, cnx, import_log_eid=None, **kwargs):
if import_log_eid is None:
import_log = cnx.create_entity('CWDataImport', cw_import_of=self,
start_timestamp=datetime.now(tz=utc),
**kwargs)
else:
import_log = cnx.entity_from_eid(import_log_eid)
import_log.cw_set(start_timestamp=datetime.now(tz=utc), **kwargs)
cnx.commit() # make changes visible
import_log.init()
return import_log
class DataFeedParser(AppObject):
__registry__ = 'parsers'
def __init__(self, cnx, source, import_log=None):
super(DataFeedParser, self).__init__(cnx)
self.source = source
self.import_log = import_log
self.stats = {'created': set(), 'updated': set(), 'checked': set()}
def normalize_url(self, url):
"""Normalize an url by looking if there is a replacement for it in
`cubicweb.sobjects.URL_MAPPING`.
This dictionary allow to redirect from one host to another, which may be
useful for example in case of test instance using production data, while
you don't want to load the external source nor to hack your `/etc/hosts`
file.
"""
# local import mandatory, it's available after registration
from cubicweb.sobjects import URL_MAPPING
for mappedurl in URL_MAPPING:
if url.startswith(mappedurl):
return url.replace(mappedurl, URL_MAPPING[mappedurl], 1)
return url
def retrieve_url(self, url):
"""Return stream linked by the given url:
* HTTP urls will be normalized (see :meth:`normalize_url`)
* handle file:// URL
* other will be considered as plain content, useful for testing purpose
For http URLs, it will try to find a cwclientlib config entry
(if available) and use it as requester.
"""
purl = urlparse(url)
if purl.scheme == 'file':
return URLLibResponseAdapter(open(url[7:]), url)
url = self.normalize_url(url)
# first, try to use cwclientlib if it's available and if the
# url matches a configuration entry in ~/.config/cwclientlibrc
try:
from cwclientlib import cwproxy_for
# parse url again since it has been normalized
cnx = cwproxy_for(url)
cnx.timeout = self.source.http_timeout
self.source.info('Using cwclientlib for %s' % url)
resp = cnx.get(url)
resp.raise_for_status()
return URLLibResponseAdapter(BytesIO(resp.content), url)
except (ImportError, ValueError, EnvironmentError) as exc:
# ImportError: not available
# ValueError: no config entry found
# EnvironmentError: no cwclientlib config file found
self.source.debug(str(exc))
# no chance with cwclientlib, fall back to former implementation
if purl.scheme in ('http', 'https'):
self.source.info('GET %s', url)
req = Request(url)
return _OPENER.open(req, timeout=self.source.http_timeout)
# url is probably plain content
return URLLibResponseAdapter(BytesIO(url.encode('ascii')), url)
def process_urls(self, urls, raise_on_error=False):
error = False
for url in urls:
self.info('pulling data from %s', url)
try:
if self.process(url, raise_on_error):
error = True
except IOError as exc:
if raise_on_error:
raise
self.import_log.record_error(
'could not pull data while processing %s: %s'
% (url, exc))
error = True
except Exception as exc:
if raise_on_error:
raise
self.import_log.record_error(str(exc))
self.exception('error while processing %s: %s',
url, exc)
error = True
return error
def process(self, url, raise_on_error=False):
"""main callback: process the url"""
raise NotImplementedError
def created_during_pull(self, entity):
return entity.eid in self.stats['created']
def updated_during_pull(self, entity):
return entity.eid in self.stats['updated']
def notify_updated(self, entity):
return self.stats['updated'].add(entity.eid)
def notify_checked(self, entity):
return self.stats['checked'].add(entity.eid)
def is_deleted(self, extid, etype, eid):
"""return True if the entity of given external id, entity type and eid
is actually deleted. Always return True by default, put more sensible
stuff in sub-classes.
"""
return True
def update_if_necessary(self, entity, attrs):
entity.complete(tuple(attrs))
# check modification date and compare attribute values to only update
# what's actually needed
self.notify_checked(entity)
mdate = attrs.get('modification_date')
if not mdate or mdate > entity.modification_date:
attrs = dict( (k, v) for k, v in attrs.items()
if v != getattr(entity, k))
if attrs:
entity.cw_set(**attrs)
self.notify_updated(entity)
class DataFeedXMLParser(DataFeedParser):
def parse(self, url):
stream = self.retrieve_url(url)
return self.parse_etree(etree.parse(stream).getroot())
def parse_etree(self, document):
return [(document,)]
def process_item(self, *args, **kwargs):
raise NotImplementedError
def is_deleted(self, extid, etype, eid):
if extid.startswith('file://'):
return exists(extid[7:])
url = self.normalize_url(extid)
# first, try to use cwclientlib if it's available and if the
# url matches a configuration entry in ~/.config/cwclientlibrc
try:
from cwclientlib import cwproxy_for
# parse url again since it has been normalized
cnx = cwproxy_for(url)
cnx.timeout = self.source.http_timeout
self.source.info('Using cwclientlib for checking %s' % url)
return cnx.get(url).status_code == 404
except (ImportError, ValueError, EnvironmentError) as exc:
# ImportError: not available
# ValueError: no config entry found
# EnvironmentError: no cwclientlib config file found
self.source.debug(str(exc))
# no chance with cwclientlib, fall back to former implementation
if urlparse(url).scheme in ('http', 'https'):
try:
_OPENER.open(url, timeout=self.source.http_timeout)
except HTTPError as ex:
if ex.code == 404:
return True
return False
class URLLibResponseAdapter(object):
"""Thin wrapper to be used to fake a value returned by urllib2.urlopen"""
def __init__(self, stream, url, code=200):
self._stream = stream
self._url = url
self.code = code
def read(self, *args):
return self._stream.read(*args)
def geturl(self):
return self._url
def getcode(self):
return self.code
# use a cookie enabled opener to use session cookie if any
_OPENER = build_opener()
try:
from logilab.common import urllib2ext
_OPENER.add_handler(urllib2ext.HTTPGssapiAuthHandler())
except ImportError: # python-kerberos not available
pass
_OPENER.add_handler(HTTPCookieProcessor(CookieJar()))