def main()

in tools/doms-data-tools/update_values_type.py [0:0]
86 lines of code
11 McCabe index (conditional complexity)

def main():
    domsconfig = configparser.ConfigParser()
    domsconfig.read(DomsInitializer._get_config_files('domsconfig.ini'))

    parser = argparse.ArgumentParser()

    parser.add_argument('-u', '--cassandra-username',
                        dest='username', help='The username used to connect to Cassandra.',
                        required=True, metavar='USERNAME')

    parser.add_argument('-p', '--cassandra-password',
                        dest='password', help='The password used to connect to Cassandra.',
                        required=True, metavar='PASSWORD')

    parser.add_argument('--cassandra', help='The hostname(s) or IP(s) of the Cassandra server(s).',
                        required=False,
                        default=domsconfig.get("cassandra", "host"),
                        dest='hosts',
                        nargs='+',
                        metavar=('localhost', '127.0.0.101'))

    parser.add_argument('--cassandraPort',
                        help='The port used to connect to Cassandra.',
                        dest='port',
                        required=False,
                        default=domsconfig.get("cassandra", "port"))

    args = parser.parse_args()

    cassHost = args.hosts
    cassPort = args.port
    cassUsername = args.username
    cassPassword = args.password
    cassKeyspace = domsconfig.get("cassandra", "keyspace")
    cassDatacenter = domsconfig.get("cassandra", "local_datacenter")
    cassVersion = int(domsconfig.get("cassandra", "protocol_version"))
    cassPolicy = domsconfig.get("cassandra", "dc_policy")

    log.info("Cassandra Host(s): %s" % (cassHost))
    log.info("Cassandra Keyspace: %s" % (cassKeyspace))
    log.info("Cassandra Datacenter: %s" % (cassDatacenter))
    log.info("Cassandra Protocol Version: %s" % (cassVersion))
    log.info("Cassandra DC Policy: %s" % (cassPolicy))
    log.info("Cassandra Auth: %s : %s" % (cassUsername, cassPassword))

    if cassPolicy == 'DCAwareRoundRobinPolicy':
        dc_policy = DCAwareRoundRobinPolicy(cassDatacenter)
        token_policy = TokenAwarePolicy(dc_policy)
    elif cassPolicy == 'WhiteListRoundRobinPolicy':
        token_policy = WhiteListRoundRobinPolicy([cassHost])
    else:
        raise ValueError(cassPolicy)

    if cassUsername and cassPassword:
        auth_provider = PlainTextAuthProvider(username=cassUsername, password=cassPassword)
    else:
        auth_provider = None

    try:
        with Cluster([host for host in cassHost.split(',')],
                     port=int(cassPort),
                     execution_profiles={
                         EXEC_PROFILE_DEFAULT: ExecutionProfile(load_balancing_policy=token_policy)
                     },
                     protocol_version=cassVersion,
                     auth_provider=auth_provider) as cluster:
            session = cluster.connect(cassKeyspace)

            cql = """
            alter table doms_data
                 add measurement_values_json text;
            """

            log.info('Creating measurement_values_json column')

            try:
                session.execute(cql)
            except:
                log.warning('measurement_values_json column creation failed; perhaps it already exists')

            cql = """
            alter table doms_data
                 add file_url text;
            """

            log.info('Creating file_url column')

            try:
                session.execute(cql)
            except:
                log.warning('file_url column creation failed; perhaps it already exists')

            for i in range(5):
                if not move_data(session):
                    if i < 4:
                        log.warning('Some move attempts failed; retrying')
                    else:
                        log.critical('Some move attempts failed; max retries exceeded')
                        exit(1)
                else:
                    break

            cql = """
            alter table doms_data
                drop measurement_values;
            """

            log.info('Dropping old measurement_values column')
            session.execute(cql)
    except NoHostAvailable as e:
        log.error("Unable to connect to Cassandra, Nexus will not be able to access local data ", e)
    except Exception as e:
        log.critical('An uncaught exception occurred')
        log.exception(e)
        exit(2)