import sys import logging import datetime import io import requests from lxml import etree from pycsw.core import metadata, repository, util import pycsw.core.config import pycsw.core.admin logging.basicConfig(format='%(message)s', level=logging.INFO) log = logging.getLogger(__name__) def setup_db(pycsw_config): """Setup database tables and indexes""" from sqlalchemy import Column, Text database = pycsw_config.get('repository', 'database') table_name = pycsw_config.get('repository', 'table', 'records') ckan_columns = [ Column('ckan_id', Text, index=True), Column('ckan_modified', Text), ] pycsw.core.admin.setup_db(database, table_name, '', create_plpythonu_functions=False, extra_columns=ckan_columns) def set_keywords(pycsw_config_file, pycsw_config, ckan_url, limit=20): """set pycsw service metadata keywords from top limit CKAN tags""" log.info('Fetching tags from %s', ckan_url) url = ckan_url + 'api/tag_counts' response = requests.get(url) tags = response.json() log.info('Deriving top %d tags', limit) # uniquify and sort by top limit tags_unique = [list(x) for x in set(tuple(x) for x in tags)] tags_sorted = sorted(tags_unique, key=lambda x: x[1], reverse=1)[0:limit] keywords = ','.join('%s' % tn[0] for tn in tags_sorted) log.info('Setting tags in pycsw configuration file %s', pycsw_config_file) pycsw_config.set('metadata:main', 'identification_keywords', keywords) with open(pycsw_config_file, 'wb') as configfile: pycsw_config.write(configfile) def load(pycsw_config, ckan_url): database = pycsw_config.get('repository', 'database') table_name = pycsw_config.get('repository', 'table', 'records') context = pycsw.core.config.StaticContext() repo = repository.Repository(database, context, table=table_name) log.info('Started gathering CKAN datasets identifiers: {0}'.format(str(datetime.datetime.now()))) query = 'api/search/dataset?qjson={"fl":"id,metadata_modified,extras_harvest_object_id,extras_metadata_source", "q":"harvest_object_id:[\\"\\" TO *]", "limit":1000, "start":%s}' start = 0 gathered_records = {} while True: url = ckan_url + query % start response = requests.get(url) listing = response.json() if not isinstance(listing, dict): raise RuntimeError, 'Wrong API response: %s' % listing results = listing.get('results') if not results: break for result in results: gathered_records[result['id']] = { 'metadata_modified': result['metadata_modified'], 'harvest_object_id': result['extras']['harvest_object_id'], 'source': result['extras'].get('metadata_source') } start = start + 1000 log.debug('Gathered %s' % start) log.info('Gather finished ({0} datasets): {1}'.format( len(gathered_records.keys()), str(datetime.datetime.now()))) existing_records = {} query = repo.session.query(repo.dataset.ckan_id, repo.dataset.ckan_modified) for row in query: existing_records[row[0]] = row[1] repo.session.close() new = set(gathered_records) - set(existing_records) deleted = set(existing_records) - set(gathered_records) changed = set() for key in set(gathered_records) & set(existing_records): if gathered_records[key]['metadata_modified'] > existing_records[key]: changed.add(key) for ckan_id in deleted: try: repo.session.begin() repo.session.query(repo.dataset.ckan_id).filter_by( ckan_id=ckan_id).delete() log.info('Deleted %s' % ckan_id) repo.session.commit() except Exception, err: repo.session.rollback() raise for ckan_id in new: ckan_info = gathered_records[ckan_id] record = get_record(context, repo, ckan_url, ckan_id, ckan_info) if not record: log.info('Skipped record %s' % ckan_id) continue try: repo.insert(record, 'local', util.get_today_and_now()) log.info('Inserted %s' % ckan_id) except Exception, err: log.error('ERROR: not inserted %s Error:%s' % (ckan_id, err)) for ckan_id in changed: ckan_info = gathered_records[ckan_id] record = get_record(context, repo, ckan_url, ckan_id, ckan_info) if not record: continue update_dict = dict([(getattr(repo.dataset, key), getattr(record, key)) \ for key in record.__dict__.keys() if key != '_sa_instance_state']) try: repo.session.begin() repo.session.query(repo.dataset).filter_by( ckan_id=ckan_id).update(update_dict) repo.session.commit() log.info('Changed %s' % ckan_id) except Exception, err: repo.session.rollback() raise RuntimeError, 'ERROR: %s' % str(err) def clear(pycsw_config): from sqlalchemy import create_engine, MetaData, Table database = pycsw_config.get('repository', 'database') table_name = pycsw_config.get('repository', 'table', 'records') log.debug('Creating engine') engine = create_engine(database) records = Table(table_name, MetaData(engine)) records.delete().execute() log.info('Table cleared') def get_record(context, repo, ckan_url, ckan_id, ckan_info): query = ckan_url + 'harvest/object/%s' url = query % ckan_info['harvest_object_id'] response = requests.get(url) if ckan_info['source'] == 'arcgis': return try: xml = etree.parse(io.BytesIO(response.content)) except Exception, err: log.error('Could not pass xml doc from %s, Error: %s' % (ckan_id, err)) return try: record = metadata.parse_record(context, xml, repo)[0] except Exception, err: log.error('Could not extract metadata from %s, Error: %s' % (ckan_id, err)) return if not record.identifier: record.identifier = ckan_id record.ckan_id = ckan_id record.ckan_modified = ckan_info['metadata_modified'] return record usage=''' Manages the CKAN-pycsw integration python ckan-pycsw.py setup [-p] Setups the necessary pycsw table on the db. python ckan-pycsw.py set_keywords [-p] -u Sets pycsw server metadata keywords from CKAN site tag list. python ckan-pycsw.py load [-p] -u Loads CKAN datasets as records into the pycsw db. python ckan-pycsw.py clear [-p] Removes all records from the pycsw table. All commands require the pycsw configuration file. By default it will try to find a file called 'default.cfg' in the same directory, but you'll probably need to provide the actual location via the -p option: paster ckan-pycsw setup -p /etc/ckan/default/pycsw.cfg The load command requires a CKAN URL from where the datasets will be pulled: paster ckan-pycsw load -p /etc/ckan/default/pycsw.cfg -u http://localhost ''' def _load_config(file_path): abs_path = os.path.abspath(file_path) if not os.path.exists(abs_path): raise AssertionError('pycsw config file {0} does not exist.'.format(abs_path)) config = SafeConfigParser() config.read(abs_path) return config import os import argparse from ConfigParser import SafeConfigParser if __name__ == '__main__': parser = argparse.ArgumentParser( description='\n'.split(usage)[0], usage=usage) parser.add_argument('command', help='Command to perform') parser.add_argument('-p', '--pycsw_config', action='store', default='default.cfg', help='pycsw config file to use.') parser.add_argument('-u', '--ckan_url', action='store', help='CKAN instance to import the datasets from.') if len(sys.argv) <= 1: parser.print_usage() sys.exit(1) arg = parser.parse_args() pycsw_config = _load_config(arg.pycsw_config) if arg.command == 'setup': setup_db(pycsw_config) elif arg.command in ['load', 'set_keywords']: if not arg.ckan_url: raise AssertionError('You need to provide a CKAN URL with -u or --ckan_url') ckan_url = arg.ckan_url.rstrip('/') + '/' if arg.command == 'load': load(pycsw_config, ckan_url) else: set_keywords(arg.pycsw_config, pycsw_config, ckan_url) elif arg.command == 'clear': clear(pycsw_config) else: print 'Unknown command {0}'.format(arg.command) sys.exit(1)