spatial-d4science/bin/ckan_pycsw.py

328 lines
10 KiB
Python

import sys
import logging
import datetime
import io
import requests
from lxml import etree
from pycsw import metadata, repository, util
import pycsw.config
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, create_engine, Integer, MetaData, \
Table, Text
database = pycsw_config.get('repository', 'database')
table_name = pycsw_config.get('repository', 'table', 'records')
log.debug('Creating engine')
engine = create_engine(database)
mdata = MetaData(engine)
log.info('Creating table %s', table_name)
records = Table(
table_name, mdata,
# core; nothing happens without these
Column('identifier', Text, primary_key=True),
Column('typename', Text,
default='csw:Record', nullable=False, index=True),
Column('schema', Text,
default='http://www.opengis.net/cat/csw/2.0.2', nullable=False,
index=True),
Column('mdsource', Text, default='local', nullable=False,
index=True),
Column('insert_date', Text, nullable=False, index=True),
Column('xml', Text, nullable=False),
Column('anytext', Text, nullable=False),
Column('language', Text, index=True),
# identification
Column('type', Text, index=True),
Column('title', Text, index=True),
Column('title_alternate', Text, index=True),
Column('abstract', Text),
Column('keywords', Text),
Column('keywordstype', Text, index=True),
Column('parentidentifier', Text, index=True),
Column('relation', Text, index=True),
Column('time_begin', Text, index=True),
Column('time_end', Text, index=True),
Column('topicategory', Text, index=True),
Column('resourcelanguage', Text, index=True),
# attribution
Column('creator', Text, index=True),
Column('publisher', Text, index=True),
Column('contributor', Text, index=True),
Column('organization', Text, index=True),
# security
Column('securityconstraints', Text),
Column('accessconstraints', Text),
Column('otherconstraints', Text),
# date
Column('date', Text, index=True),
Column('date_revision', Text, index=True),
Column('date_creation', Text, index=True),
Column('date_publication', Text, index=True),
Column('date_modified', Text, index=True),
Column('format', Text, index=True),
Column('source', Text, index=True),
# geospatial
Column('crs', Text, index=True),
Column('geodescode', Text, index=True),
Column('denominator', Integer, index=True),
Column('distancevalue', Integer, index=True),
Column('distanceuom', Text, index=True),
Column('wkt_geometry', Text),
# service
Column('servicetype', Text, index=True),
Column('servicetypeversion', Text, index=True),
Column('operation', Text, index=True),
Column('couplingtype', Text, index=True),
Column('operateson', Text, index=True),
Column('operatesonidentifier', Text, index=True),
Column('operatesoname', Text, index=True),
# additional
Column('degree', Text, index=True),
Column('classification', Text, index=True),
Column('conditionapplyingtoaccessanduse', Text, index=True),
Column('lineage', Text, index=True),
Column('responsiblepartyrole', Text, index=True),
Column('specificationtitle', Text, index=True),
Column('specificationdate', Text, index=True),
Column('specificationdatetype', Text, index=True),
# distribution
# links: format "name,description,protocol,url[^,,,[^,,,]]"
Column('links', Text, index=True),
Column('ckan_id', Text, index=True),
Column('ckan_modified', Text),
)
records.create()
def load(pycsw_config, ckan_url):
database = pycsw_config.get('repository', 'database')
table_name = pycsw_config.get('repository', 'table', 'records')
context = pycsw.config.StaticContext()
repo = repository.Repository(database, context, table=table_name)
ckan_url = ckan_url.lstrip('/') + '/'
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 load [-p] -u
Loads CKAN datasets as records into the pycsw db.
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/pycsw/default.cfg
The load command requires a CKAN URL from where the datasets will be pulled:
paster ckan-pycsw setup -p /etc/pycsw/default.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='Path to pycsw config file')
parser.add_argument('-u', '--ckan_url',
action='store',
help='CKAN URL')
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 == 'load':
if not arg.ckan_url:
raise AssertionError('You need to provide a CKAN URL with -u or --ckan_url')
load(pycsw_config, arg.ckan_url)
elif arg.command == 'clear':
clear(pycsw_config)
else:
print 'Unknown command {0}'.format(arg.command)
sys.exit(1)