Use The Paho Mqtt Python Library - Digi Connect EZ 4 User Manual

Applications
Use the Paho MQTT python library
Your Connect EZ device includes support for the Paho MQTT python library. MQTT is a lightweight
messaging protocol used to communicate with various applications including cloud-based
applications such as Amazon Web Services and Microsoft Azure. The following is example code that
reads CPU and RAM usage on the device, updates the device firmware, then publishes information
about DHCP clients and system information to the MQTT server at 192.168.1.100. The MQTT server IP
is configurable.
"""
MQTT client example:
- Reporting some device metrics from runt
- Reporting DHCP clients
- Firmware update feature (simple implementation, read TODO in cmd_fwupdate)
"""
import sys
import time
import paho.mqtt.client as mqtt
import json
from acl import runt, config
from http import HTTPStatus
import urllib.request
import tempfile
import os
from digidevice import cli
POLL_TIME = 60
def cmd_reboot(params):
print("Rebooting unit...")
try:
cli.execute("reboot", 10)
except:
print("Failed to run 'reboot' command")
return HTTPStatus.INTERNAL_SERVER_ERROR
return HTTPStatus.OK
def cmd_fwupdate(params):
try:
fw_uri = params["uri"]
except:
print("Firmware file URI not passed")
return HTTPStatus.BAD_REQUEST
print("Request to update firmware with URI: {}".format(fw_uri))
try:
fd, fname = tempfile.mkstemp()
os.close(fd)
try:
urllib.request.urlretrieve(fw_uri, fname)
except:
print("Failed to download FW file from URI {}".format(fw_uri))
return HTTPStatus.NOT_FOUND
try:
Digi Connect EZ 4/4i User Guide
Use the Paho MQTT python library
646