Source code for examples.datastore_config_server

#!/usr/local/bin/python
"""Simple XML-RPC Server to run on the datastore server.

This daemon should be run on HiSPARC's datastore server.  It will
handle the cluster layouts and station passwords.  When an update is
necessary, it will reload the HTTP daemon.

The basis for this code was ripped from the python SimpleXMLRPCServer
library documentation and extended.

"""

import hashlib
import os
import urllib.error
import urllib.parse
import urllib.request

from xmlrpc.server import SimpleXMLRPCRequestHandler, SimpleXMLRPCServer

HASH = '/tmp/hash_datastore'
DATASTORE_CFG = '/databases/frome/station_list.csv'
CFG_URL = 'https://data.hisparc.nl/config/datastore'
DATASTORE_XMLRPC_SERVER = ('192.168.99.13', 8001)
RELOAD_PATH = '/tmp/uwsgi-reload.me'




def reload_datastore():
    """Load datastore config and reload datastore, if necessary"""

    datastore_cfg = urllib.request.urlopen(CFG_URL).read()
    new_hash = hashlib.sha1(datastore_cfg).hexdigest()

    try:
        with open(HASH) as file:
            old_hash = file.readline()
    except OSError:
        old_hash = None

    if new_hash == old_hash:
        return True
    else:
        with open(DATASTORE_CFG, 'w') as file:
            file.write(datastore_cfg)

        # reload uWSGI
        with open(RELOAD_PATH, 'a'):
            os.utime(RELOAD_PATH, None)

        with open(HASH, 'w') as file:
            file.write(new_hash)

    return True



if __name__ == '__main__':
    # Restrict to a particular path.
    class RequestHandler(SimpleXMLRPCRequestHandler):
        rpc_paths = ('/RPC2',)

    # Create server
    server = SimpleXMLRPCServer(DATASTORE_XMLRPC_SERVER, requestHandler=RequestHandler)
    server.register_introspection_functions()

    server.register_function(reload_datastore)

    # Run the server's main loop
    server.serve_forever()