def core_connect()

in groups/master/ggd/heartbeat.py [0:0]

• 44 lines of code
• 5 McCabe index (conditional complexity)

def core_connect(device_name, config_file, root_ca, certificate, private_key,
                 group_ca_path):
    # read the config file
    cfg = GroupConfigFile(config_file)

    # determine heartbeat device's thing name and orient MQTT client to GG Core
    heartbeat_name = cfg['devices'][device_name]['thing_name']
    iot_endpoint = cfg['misc']['iot_endpoint']
    local_core = None

    # Discover Greengrass Core
    dip = DiscoveryInfoProvider()
    dip.configureEndpoint(iot_endpoint)
    dip.configureCredentials(
        caPath=root_ca, certPath=certificate, keyPath=private_key
    )
    dip.configureTimeout(10)  # 10 sec
    log.info("[hb] Discovery using CA: {0} cert: {1} prv_key: {2}".format(
        root_ca, certificate, private_key
    ))
    # Now discover the groups in which this device is a member.
    # The heartbeat should only be in one group
    discovered, discovery_info = utils.ggc_discovery(
        heartbeat_name, dip, retry_count=10, max_groups=1
    )

    ca_list = discovery_info.getAllCas()
    group_id, ca = ca_list[0]
    group_ca_file = utils.save_group_ca(ca, group_ca_path, group_id)

    if discovered is False:
        log.error(
            "[hb] Discovery failed for: {0} when connecting to "
            "service endpoint: {1}".format(
                heartbeat_name, iot_endpoint
            ))
        return
    log.info("[hb] Discovery success")

    mqttc = AWSIoTMQTTClient(heartbeat_name)

    # find this device Group's core
    for group in discovery_info.getAllGroups():
        utils.dump_core_info_list(group.coreConnectivityInfoList)
        local_core = group.getCoreConnectivityInfo(cfg['core']['thing_arn'])
        if local_core:
            log.info('[hb] Found the local core and Group CA.')
            break

    if not local_core:
        raise EnvironmentError("[hb] Couldn't find the local Core")

    # local Greengrass Core discovered, now connect to Core from this Device
    log.info("[hb] gca_file:{0} cert:{1}".format(group_ca_file, certificate))
    mqttc.configureCredentials(group_ca_file, private_key, certificate)
    mqttc.configureOfflinePublishQueueing(10, DROP_OLDEST)

    if not utils.mqtt_connect(mqtt_client=mqttc, core_info=local_core):
        raise EnvironmentError("[hb] Connection to GG Core MQTT failed.")

    return mqttc, heartbeat_name