575 lines
24 KiB
Python
575 lines
24 KiB
Python
import urllib
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import urllib2
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import urlparse
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import httplib
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import datetime
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import socket
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from sqlalchemy import exists
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from ckan.lib.base import c
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from ckan import model
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from ckan.logic import ValidationError, NotFound, get_action
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from ckan.lib.helpers import json
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from ckan.lib.munge import munge_name
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from ckan.plugins import toolkit
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from ckanext.harvest.model import HarvestJob, HarvestObject, HarvestGatherError
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import logging
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log = logging.getLogger(__name__)
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from base import HarvesterBase
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class CKANHarvester(HarvesterBase):
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'''
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A Harvester for CKAN instances
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'''
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config = None
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api_version = 2
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action_api_version = 3
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def _get_action_api_offset(self):
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return '/api/%d/action' % self.action_api_version
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def _get_search_api_offset(self):
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return '%s/package_search' % self._get_action_api_offset()
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def _get_content(self, url):
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http_request = urllib2.Request(url=url)
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api_key = self.config.get('api_key')
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if api_key:
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http_request.add_header('Authorization', api_key)
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try:
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http_response = urllib2.urlopen(http_request)
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except urllib2.HTTPError, e:
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if e.getcode() == 404:
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raise ContentNotFoundError('HTTP error: %s' % e.code)
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else:
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raise ContentFetchError('HTTP error: %s' % e.code)
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except urllib2.URLError, e:
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raise ContentFetchError('URL error: %s' % e.reason)
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except httplib.HTTPException, e:
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raise ContentFetchError('HTTP Exception: %s' % e)
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except socket.error, e:
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raise ContentFetchError('HTTP socket error: %s' % e)
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except Exception, e:
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raise ContentFetchError('HTTP general exception: %s' % e)
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return http_response.read()
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def _get_group(self, base_url, group_name):
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url = base_url + self._get_action_api_offset() + '/group_show?id=' + \
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munge_name(group_name)
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try:
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content = self._get_content(url)
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return json.loads(content)
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except (ContentFetchError, ValueError):
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log.debug('Could not fetch/decode remote group')
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raise RemoteResourceError('Could not fetch/decode remote group')
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def _get_organization(self, base_url, org_name):
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url = base_url + self._get_action_api_offset() + \
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'/organization_show?id=' + org_name
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try:
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content = self._get_content(url)
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content_dict = json.loads(content)
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return content_dict['result']
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except (ContentFetchError, ValueError, KeyError):
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log.debug('Could not fetch/decode remote group')
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raise RemoteResourceError(
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'Could not fetch/decode remote organization')
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def _set_config(self, config_str):
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if config_str:
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self.config = json.loads(config_str)
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if 'api_version' in self.config:
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self.api_version = int(self.config['api_version'])
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log.debug('Using config: %r', self.config)
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else:
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self.config = {}
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def info(self):
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return {
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'name': 'ckan',
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'title': 'CKAN',
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'description': 'Harvests remote CKAN instances',
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'form_config_interface': 'Text'
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}
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def validate_config(self, config):
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if not config:
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return config
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try:
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config_obj = json.loads(config)
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if 'api_version' in config_obj:
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try:
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int(config_obj['api_version'])
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except ValueError:
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raise ValueError('api_version must be an integer')
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if 'default_tags' in config_obj:
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if not isinstance(config_obj['default_tags'], list):
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raise ValueError('default_tags must be a list')
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if 'default_groups' in config_obj:
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if not isinstance(config_obj['default_groups'], list):
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raise ValueError('default_groups must be a list')
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# Check if default groups exist
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context = {'model': model, 'user': c.user}
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for group_name in config_obj['default_groups']:
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try:
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group = get_action('group_show')(
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context, {'id': group_name})
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except NotFound, e:
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raise ValueError('Default group not found')
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if 'default_extras' in config_obj:
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if not isinstance(config_obj['default_extras'], dict):
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raise ValueError('default_extras must be a dictionary')
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if 'user' in config_obj:
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# Check if user exists
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context = {'model': model, 'user': c.user}
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try:
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user = get_action('user_show')(
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context, {'id': config_obj.get('user')})
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except NotFound:
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raise ValueError('User not found')
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for key in ('read_only', 'force_all'):
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if key in config_obj:
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if not isinstance(config_obj[key], bool):
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raise ValueError('%s must be boolean' % key)
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except ValueError, e:
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raise e
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return config
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def gather_stage(self, harvest_job):
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log.debug('In CKANHarvester gather_stage (%s)',
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harvest_job.source.url)
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toolkit.requires_ckan_version(min_version='2.0')
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get_all_packages = True
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self._set_config(harvest_job.source.config)
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# URL cleanup
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parts = urlparse.urlsplit(harvest_job.source.url)
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if parts.username and parts.password:
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if parts.port is None:
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cleaned_url = urlparse.urlunsplit((
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parts.scheme,
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parts.hostname,
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url_path,
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parts.query,
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parts.fragment
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))
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else:
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cleaned_url = urlparse.urlunsplit((
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parts.scheme,
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parts.hostname,
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parts.port,
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url_path,
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parts.query
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))
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# Get source URL
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remote_ckan_base_url = cleaned_url.rstrip('/')
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# Filter in/out datasets from particular organizations
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fq_terms = []
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org_filter_include = self.config.get('organizations_filter_include', [])
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org_filter_exclude = self.config.get('organizations_filter_exclude', [])
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if org_filter_include:
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fq_terms.append(' OR '.join(
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'organization:%s' % org_name for org_name in org_filter_include))
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elif org_filter_exclude:
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fq_terms.extend(
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'-organization:%s' % org_name for org_name in org_filter_exclude)
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# Ideally we can request from the remote CKAN only those datasets
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# modified since the last completely successful harvest.
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last_error_free_job = self._last_error_free_job(harvest_job)
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log.debug('Last error-free job: %r', last_error_free_job)
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if (last_error_free_job and
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not self.config.get('force_all', False)):
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get_all_packages = False
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# Request only the datasets modified since
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last_time = last_error_free_job.gather_started
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# Note: SOLR works in UTC, and gather_started is also UTC, so
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# this should work as long as local and remote clocks are
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# relatively accurate. Going back a little earlier, just in case.
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get_changes_since = \
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(last_time - datetime.timedelta(hours=1)).isoformat()
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log.info('Searching for datasets modified since: %s UTC',
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get_changes_since)
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fq_since_last_time = 'metadata_modified:[{since}Z TO *]' \
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.format(since=get_changes_since)
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try:
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pkg_dicts = self._search_for_datasets(
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remote_ckan_base_url,
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fq_terms + [fq_since_last_time])
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except SearchError, e:
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log.info('Searching for datasets changed since last time '
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'gave an error: %s', e)
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get_all_packages = True
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if not get_all_packages and not pkg_dicts:
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log.info('No datasets have been updated on the remote '
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'CKAN instance since the last harvest job %s',
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last_time)
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return None
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# Fall-back option - request all the datasets from the remote CKAN
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if get_all_packages:
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# Request all remote packages
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try:
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pkg_dicts = self._search_for_datasets(remote_ckan_base_url,
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fq_terms)
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except SearchError, e:
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log.info('Searching for all datasets gave an error: %s', e)
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self._save_gather_error(
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'Unable to search remote CKAN for datasets:%s url:%s'
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'terms:%s' % (e, remote_ckan_base_url, fq_terms),
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harvest_job)
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return None
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if not pkg_dicts:
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self._save_gather_error(
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'No datasets found at CKAN: %s' % remote_ckan_base_url,
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harvest_job)
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return None
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# Create harvest objects for each dataset
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try:
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package_ids = set()
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object_ids = []
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for pkg_dict in pkg_dicts:
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if pkg_dict['id'] in package_ids:
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log.info('Discarding duplicate dataset %s - probably due '
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'to datasets being changed at the same time as '
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'when the harvester was paging through',
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pkg_dict['id'])
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continue
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package_ids.add(pkg_dict['id'])
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log.debug('Creating HarvestObject for %s %s',
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pkg_dict['name'], pkg_dict['id'])
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obj = HarvestObject(guid=pkg_dict['id'],
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job=harvest_job,
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content=json.dumps(pkg_dict))
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obj.save()
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object_ids.append(obj.id)
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return object_ids
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except Exception, e:
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self._save_gather_error('%r' % e.message, harvest_job)
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def _search_for_datasets(self, remote_ckan_base_url, fq_terms=None):
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'''Does a dataset search on a remote CKAN and returns the results.
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Deals with paging to return all the results, not just the first page.
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'''
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base_search_url = remote_ckan_base_url + self._get_search_api_offset()
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params = {'rows': '100', 'start': '0'}
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# There is the worry that datasets will be changed whilst we are paging
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# through them.
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# * In SOLR 4.7 there is a cursor, but not using that yet
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# because few CKANs are running that version yet.
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# * However we sort, then new names added or removed before the current
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# page would cause existing names on the next page to be missed or
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# double counted.
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# * Another approach might be to sort by metadata_modified and always
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# ask for changes since (and including) the date of the last item of
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# the day before. However if the entire page is of the exact same
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# time, then you end up in an infinite loop asking for the same page.
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# * We choose a balanced approach of sorting by ID, which means
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# datasets are only missed if some are removed, which is far less
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# likely than any being added. If some are missed then it is assumed
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# they will harvested the next time anyway. When datasets are added,
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# we are at risk of seeing datasets twice in the paging, so we detect
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# and remove any duplicates.
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params['sort'] = 'id asc'
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if fq_terms:
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params['fq'] = ' '.join(fq_terms)
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pkg_dicts = []
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pkg_ids = set()
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previous_content = None
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while True:
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url = base_search_url + '?' + urllib.urlencode(params)
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log.debug('Searching for CKAN datasets: %s', url)
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try:
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content = self._get_content(url)
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except ContentFetchError, e:
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raise SearchError(
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'Error sending request to search remote '
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'CKAN instance %s using URL %r. Error: %s' %
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(remote_ckan_base_url, url, e))
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if previous_content and content == previous_content:
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raise SearchError('The paging doesn\'t seem to work. URL: %s' %
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url)
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try:
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response_dict = json.loads(content)
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except ValueError:
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raise SearchError('Response from remote CKAN was not JSON: %r'
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% content)
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try:
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pkg_dicts_page = response_dict.get('result', {}).get('results',
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[])
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except ValueError:
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raise SearchError('Response JSON did not contain '
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'result/results: %r' % response_dict)
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# Weed out any datasets found on previous pages (should datasets be
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# changing while we page)
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ids_in_page = set(p['id'] for p in pkg_dicts_page)
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duplicate_ids = ids_in_page & pkg_ids
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if duplicate_ids:
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pkg_dicts_page = [p for p in pkg_dicts_page
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if p['id'] not in duplicate_ids]
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pkg_ids |= ids_in_page
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pkg_dicts.extend(pkg_dicts_page)
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if len(pkg_dicts_page) == 0:
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break
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params['start'] = str(int(params['start']) + int(params['rows']))
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return pkg_dicts
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@classmethod
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def _last_error_free_job(cls, harvest_job):
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# TODO weed out cancelled jobs somehow.
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# look for jobs with no gather errors
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jobs = \
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model.Session.query(HarvestJob) \
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.filter(HarvestJob.source == harvest_job.source) \
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.filter(HarvestJob.gather_started != None) \
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.filter(HarvestJob.status == 'Finished') \
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.filter(HarvestJob.id != harvest_job.id) \
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.filter(
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~exists().where(
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HarvestGatherError.harvest_job_id == HarvestJob.id)) \
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.order_by(HarvestJob.gather_started.desc())
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# now check them until we find one with no fetch/import errors
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# (looping rather than doing sql, in case there are lots of objects
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# and lots of jobs)
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for job in jobs:
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for obj in job.objects:
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if obj.current is False and \
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obj.report_status != 'not modified':
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# unsuccessful, so go onto the next job
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break
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else:
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return job
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def fetch_stage(self, harvest_object):
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# Nothing to do here - we got the package dict in the search in the
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# gather stage
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return True
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def import_stage(self, harvest_object):
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log.debug('In CKANHarvester import_stage')
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context = {'model': model, 'session': model.Session,
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'user': self._get_user_name()}
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if not harvest_object:
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log.error('No harvest object received')
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return False
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if harvest_object.content is None:
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self._save_object_error('Empty content for object %s' %
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harvest_object.id,
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harvest_object, 'Import')
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return False
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self._set_config(harvest_object.job.source.config)
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try:
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package_dict = json.loads(harvest_object.content)
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if package_dict.get('type') == 'harvest':
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log.warn('Remote dataset is a harvest source, ignoring...')
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return True
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# Set default tags if needed
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default_tags = self.config.get('default_tags', [])
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if default_tags:
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if not 'tags' in package_dict:
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package_dict['tags'] = []
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package_dict['tags'].extend(
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[t for t in default_tags if t not in package_dict['tags']])
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remote_groups = self.config.get('remote_groups', None)
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if not remote_groups in ('only_local', 'create'):
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# Ignore remote groups
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package_dict.pop('groups', None)
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else:
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if not 'groups' in package_dict:
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package_dict['groups'] = []
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# check if remote groups exist locally, otherwise remove
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validated_groups = []
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for group_name in package_dict['groups']:
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try:
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data_dict = {'id': group_name}
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group = get_action('group_show')(context, data_dict)
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if self.api_version == 1:
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validated_groups.append(group['name'])
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else:
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validated_groups.append(group['id'])
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except NotFound, e:
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log.info('Group %s is not available', group_name)
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if remote_groups == 'create':
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try:
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group = self._get_group(harvest_object.source.url, group_name)
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except RemoteResourceError:
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log.error('Could not get remote group %s', group_name)
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continue
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for key in ['packages', 'created', 'users', 'groups', 'tags', 'extras', 'display_name']:
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group.pop(key, None)
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get_action('group_create')(context, group)
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log.info('Group %s has been newly created', group_name)
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if self.api_version == 1:
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validated_groups.append(group['name'])
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else:
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validated_groups.append(group['id'])
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package_dict['groups'] = validated_groups
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# Local harvest source organization
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source_dataset = get_action('package_show')(context, {'id': harvest_object.source.id})
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local_org = source_dataset.get('owner_org')
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remote_orgs = self.config.get('remote_orgs', None)
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if not remote_orgs in ('only_local', 'create'):
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# Assign dataset to the source organization
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package_dict['owner_org'] = local_org
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else:
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if not 'owner_org' in package_dict:
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package_dict['owner_org'] = None
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# check if remote org exist locally, otherwise remove
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validated_org = None
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remote_org = package_dict['owner_org']
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if remote_org:
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try:
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data_dict = {'id': remote_org}
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org = get_action('organization_show')(context, data_dict)
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validated_org = org['id']
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except NotFound, e:
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log.info('Organization %s is not available', remote_org)
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if remote_orgs == 'create':
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try:
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try:
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org = self._get_organization(harvest_object.source.url, remote_org)
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except RemoteResourceError:
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# fallback if remote CKAN exposes organizations as groups
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# this especially targets older versions of CKAN
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org = self._get_group(harvest_object.source.url, remote_org)
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for key in ['packages', 'created', 'users', 'groups', 'tags', 'extras', 'display_name', 'type']:
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org.pop(key, None)
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get_action('organization_create')(context, org)
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log.info('Organization %s has been newly created', remote_org)
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validated_org = org['id']
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except (RemoteResourceError, ValidationError):
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log.error('Could not get remote org %s', remote_org)
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package_dict['owner_org'] = validated_org or local_org
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# Set default groups if needed
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default_groups = self.config.get('default_groups', [])
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if default_groups:
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if not 'groups' in package_dict:
|
|
package_dict['groups'] = []
|
|
package_dict['groups'].extend(
|
|
[g for g in default_groups
|
|
if g not in package_dict['groups']])
|
|
|
|
# Set default extras if needed
|
|
default_extras = self.config.get('default_extras', {})
|
|
def get_extra(key, package_dict):
|
|
for extra in package_dict.get('extras', []):
|
|
if extra['key'] == key:
|
|
return extra
|
|
if default_extras:
|
|
override_extras = self.config.get('override_extras', False)
|
|
if not 'extras' in package_dict:
|
|
package_dict['extras'] = {}
|
|
for key, value in default_extras.iteritems():
|
|
existing_extra = get_extra(key, package_dict)
|
|
if existing_extra and not override_extras:
|
|
continue # no need for the default
|
|
if existing_extra:
|
|
package_dict['extras'].remove(existing_extra)
|
|
# Look for replacement strings
|
|
if isinstance(value, basestring):
|
|
value = value.format(
|
|
harvest_source_id=harvest_object.job.source.id,
|
|
harvest_source_url=
|
|
harvest_object.job.source.url.strip('/'),
|
|
harvest_source_title=
|
|
harvest_object.job.source.title,
|
|
harvest_job_id=harvest_object.job.id,
|
|
harvest_object_id=harvest_object.id,
|
|
dataset_id=package_dict['id'])
|
|
|
|
package_dict['extras'].append({'key': key, 'value': value})
|
|
|
|
for resource in package_dict.get('resources', []):
|
|
# Clear remote url_type for resources (eg datastore, upload) as
|
|
# we are only creating normal resources with links to the
|
|
# remote ones
|
|
resource.pop('url_type', None)
|
|
|
|
# Clear revision_id as the revision won't exist on this CKAN
|
|
# and saving it will cause an IntegrityError with the foreign
|
|
# key.
|
|
resource.pop('revision_id', None)
|
|
|
|
result = self._create_or_update_package(
|
|
package_dict, harvest_object, package_dict_form='package_show')
|
|
|
|
return result
|
|
except ValidationError, e:
|
|
self._save_object_error('Invalid package with GUID %s: %r' %
|
|
(harvest_object.guid, e.error_dict),
|
|
harvest_object, 'Import')
|
|
except Exception, e:
|
|
self._save_object_error('%s' % e, harvest_object, 'Import')
|
|
|
|
|
|
class ContentFetchError(Exception):
|
|
pass
|
|
|
|
class ContentNotFoundError(ContentFetchError):
|
|
pass
|
|
|
|
class RemoteResourceError(Exception):
|
|
pass
|
|
|
|
|
|
class SearchError(Exception):
|
|
pass
|