我一直在使用Google IOT Arm示例代码（原始代码https://github.com/ARM-software/Cloud-IoT-Core-Kit-Examples/blob/master/CPUTemp/pi_cpu_temp_mqtt.py）来为我的微型水培设置一个简单的传感器记录器。
效果一直很好。有效负载每60秒就会将传感器数据发送到Google Cloud，我在Data Studio中对其进行跟踪。
我添加了Adafruit传感器，并且愉快地跟踪了几周的传感器数据。
问题
我的路由器每天凌晨3点自动重启一次，这导致我的Python代码挂起。我可以简单地停止重新启动，而宁愿完全捕获或避免该错误，以防将来出现更多异常连接问题。
希望
能够重新连接并继续向Google Cloud发送数据的功能。
将来我将添加控制功能，例如中继灯和风扇，因此可靠性对于帮助植物生长至关重要。
完整错误
Traceback (most recent call last):
File "lily_telemetry.py", line 220, in <module>
main()
File "lily_telemetry.py", line 217, in main
main()
File "lily_telemetry.py", line 185, in main
client.connect(args.mqtt_bridge_hostname, args.mqtt_bridge_port)
File "/home/pi/.local/lib/python3.5/site-packages/paho/mqtt/client.py", line 839, in connect
return self.reconnect()
File "/home/pi/.local/lib/python3.5/site-packages/paho/mqtt/client.py", line 962, in reconnect
sock = socket.create_connection((self._host, self._port), source_address=(self._bind_address, 0))
File "/usr/lib/python3.5/socket.py", line 694, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
File "/usr/lib/python3.5/socket.py", line 733, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -3] Temporary failure in name resolution
代码
#!/usr/bin/python
import argparse
import json
import datetime
import time
import ssl
import subprocess
import board
import busio
import adafruit_mcp9808
import adafruit_tsl2591
import digitalio
import jwt
import paho.mqtt.client as mqtt
# Update and publish temperature readings at a rate of SENSOR_POLL per second.
SENSOR_POLL=60
# Initialise I2C Master Bus
i2c_bus = busio.I2C(board.SCL, board.SDA)
# Set temperature sensor inputs MCP9808 board
mcp1 = adafruit_mcp9808.MCP9808(i2c_bus)
mcp2 = adafruit_mcp9808.MCP9808(i2c_bus,0x1C)
# Set light sensor inputs TSL2591 board
tsl = adafruit_tsl2591.TSL2591(i2c_bus)
def create_jwt(project_id, private_key_file, algorithm):
"""Create a JWT (https://jwt.io) to establish an MQTT connection."""
token = {
'iat': datetime.datetime.utcnow(),
'exp': datetime.datetime.utcnow() + datetime.timedelta(minutes=60),
'aud': project_id
}
with open(private_key_file, 'r') as f:
private_key = f.read()
print('Creating JWT using {} from private key file {}' .format(algorithm, private_key_file))
return jwt.encode(token, private_key, algorithm=algorithm)
def error_str(rc):
"""Convert a Paho error to a human readable string."""
return '{}: {}'.format(rc, mqtt.error_string(rc))
class Device(object):
"""Represents the state of a single device."""
def __init__(self):
self.temperature = 0
self.connected = False
def update_sensor_data(self):
# CPU Temp
rawdata = subprocess.check_output(["sudo", "/opt/vc/bin/vcgencmd", "measure_temp"]).decode().split('=', 1)[-1].rstrip()
sendtemp = '"temp":"{}"' .format(rawdata.replace("'", "-").split("-", 1)[0])
self.temperature = sendtemp
# Temperature Sensor 1 Data
self.sensortemperature_1 = '"sensor_temp_1":"{}"' .format(mcp1.temperature)
# Temperature Sensor 2 Data
self.sensortemperature_2 = '"sensor_temp_2":"{}"' .format(mcp2.temperature)
# Light Sensor Data
lux = tsl.lux
infrared = tsl.infrared
visible = tsl.visible
full_spectrum = tsl.full_spectrum
self.lightsensor_lux = '"light_sensor_lux":"{}"' .format(round(lux,4))
self.lightsensor_infrared = '"light_sensor_infrared":"{}"' .format(infrared)
self.lightsensor_visible = '"light_sensor_visible":"{}"' .format(visible)
self.lightsensor_full_spectrum = '"light_sensor_full_spectrum":"{}"' .format(full_spectrum)
def wait_for_connection(self, timeout):
"""Wait for the device to become connected."""
total_time = 0
while not self.connected and total_time < timeout:
time.sleep(1)
total_time += 1
if not self.connected:
raise RuntimeError('Could not connect to MQTT bridge.')
def on_connect(self, unused_client, unused_userdata, unused_flags, rc):
"""Callback for when a device connects."""
print('Connection Result:', error_str(rc))
self.connected = True
def on_disconnect(self, unused_client, unused_userdata, rc):
"""Callback for when a device disconnects."""
print('Disconnected:', error_str(rc))
print('...')
main()
self.connected = False
def on_publish(self, unused_client, unused_userdata, unused_mid):
"""Callback when the device receives a PUBACK from the MQTT bridge."""
print('Published message.')
print("Waiting {} seconds." .format(SENSOR_POLL))
def on_subscribe(self, unused_client, unused_userdata, unused_mid,
granted_qos):
"""Callback when the device receives a SUBACK from the MQTT bridge."""
print('Subscribed: ', granted_qos)
if granted_qos[0] == 128:
print('Subscription failed.')
def parse_command_line_args():
"""Parse command line arguments."""
parser = argparse.ArgumentParser(
description='Lily Grow Logging using MQTT')
parser.add_argument(
'--project_id', required=True, help='GCP cloud project name')
parser.add_argument(
'--registry_id', required=True, help='Cloud IoT registry id')
parser.add_argument('--device_id', required=True, help='Cloud IoT device id')
parser.add_argument(
'--private_key_file', required=True, help='Path to private key file.')
parser.add_argument(
'--algorithm',
choices=('RS256', 'ES256'),
required=True,
help='Which encryption algorithm to use to generate the JWT.')
parser.add_argument(
'--cloud_region', default='us-central1', help='GCP cloud region')
parser.add_argument(
'--ca_certs',
default='roots.pem',
help='CA root certificate. Get from https://pki.google.com/roots.pem')
parser.add_argument(
'--num_messages',
type=int,
default=60,
help='Number of messages to publish.')
parser.add_argument(
'--mqtt_bridge_hostname',
default='mqtt.googleapis.com',
help='MQTT bridge hostname.')
parser.add_argument(
'--mqtt_bridge_port', default=8883, help='MQTT bridge port.')
return parser.parse_args()
def main():
args = parse_command_line_args()
# Create our MQTT client and connect to Cloud IoT.
client = mqtt.Client(
client_id='projects/{}/locations/{}/registries/{}/devices/{}'.format(
args.project_id, args.cloud_region, args.registry_id, args.device_id))
client.username_pw_set(
username='unused',
password=create_jwt(args.project_id, args.private_key_file,
args.algorithm))
client.tls_set(ca_certs=args.ca_certs, tls_version=ssl.PROTOCOL_TLSv1_2)
device = Device()
client.on_connect = device.on_connect
client.on_publish = device.on_publish
client.on_disconnect = device.on_disconnect
client.on_subscribe = device.on_subscribe
client.connect(args.mqtt_bridge_hostname, args.mqtt_bridge_port)
client.loop_start()
# This is the topic that the device will publish telemetry events (temperature
# data) to.
mqtt_telemetry_topic = '/devices/{}/events'.format(args.device_id)
# Wait up to 5 seconds for the device to connect.
device.wait_for_connection(5)
# Update and publish temperature readings at a rate of SENSOR_POLL per second.
for _ in range(args.num_messages):
device.update_sensor_data()
# Time
sendtime = '"datetime":"{}"'.format(datetime.datetime.now().strftime("%Y-%m-%d"" ""%H:%M:%S.%f"))
# Payload
payload = '{{''{},{},{},{},{},{},{},{}''}}'.format(device.temperature, device.sensortemperature_1,device.sensortemperature_2,device.lightsensor_lux,device.lightsensor_infrared,device.lightsensor_visible,device.lightsensor_full_spectrum,sendtime)
# Message
print('Payload: {}'.format(payload))
# Publish, Sleep
client.publish(mqtt_telemetry_topic, payload, qos=1)
time.sleep(SENSOR_POLL)
client.disconnect()
client.loop_stop()
print('Finished loop successfully. Goodbye!')
main()
if __name__ == '__main__':
main()
答案 0 :(得分：1)
使用from socket import gaierror
try:
client.connect(args.mqtt_bridge_hostname, args.mqtt_bridge_port)
except gaierror as e:
print('Gaierror {}.'.format(e))
print('Waiting {} seconds before restarting Main'.format(sensor_delay))
time.sleep(sensor_delay)
restartlily()
restartlily()从顶部重新启动整个脚本