Updating miniconf utility to use correlation data

This commit is contained in:
Ryan Summers 2021-05-04 14:21:00 +02:00
parent 1f8f63018a
commit a3ff8aae75
1 changed files with 58 additions and 26 deletions

View File

@ -10,6 +10,7 @@ import asyncio
import json
import logging
import sys
import uuid
from gmqtt import Client as MqttClient
@ -33,28 +34,52 @@ class Miniconf:
client: A connected MQTT5 client.
prefix: The MQTT toptic prefix of the device to control.
"""
self.uuid = uuid.uuid1(prefix)
self.request_id = 0
self.client = client
self.prefix = prefix
self.inflight = {}
self.client.on_message = self._handle_response
self.client.subscribe(f'{prefix}/response/#')
def _handle_response(self, _client, topic, payload, *_args, **_kwargs):
def _handle_response(self, _client, _topic, payload, _qos, properties):
"""Callback function for when messages are received over MQTT.
Args:
_client: The MQTT client.
topic: The topic that the message was received on.
_topic: The topic that the message was received on.
payload: The payload of the message.
_qos: The quality-of-service level of the received packet
properties: A dictionary of properties associated with the message.
"""
if topic not in self.inflight:
# TODO use correlation_data to distinguish clients and requests
logger.warning('Unexpected response on topic: %s', topic)
# Extract corrleation data from the properties
try:
correlation_data = json.loads(properties['correlation_data'])
except (json.decoder.JSONDecodeError, KeyError):
logger.warning('Ignoring message with invalid correlation data')
return
# Validate the correlation data.
try:
if correlation_data['id'] != self.uuid.hex:
logger.info('Ignoring correlation data for different ID')
return
pid = correlation_data['pid']
except KeyError:
logger.warning('Ignoring unknown correlation data: %s', correlation_data)
return
if pid not in self.inflight:
logger.warning('Unexpected pid: %s', pid)
return
try:
response = json.loads(payload)
self.inflight[topic].set_result((response['code'], response['msg']))
del self.inflight[topic]
self.inflight[pid].set_result((response['code'], response['msg']))
del self.inflight[pid]
except json.decoder.JSONDecodeError:
logger.warning('Invalid response format: %s', payload)
async def command(self, path, value):
"""Write the provided data to the specified path.
@ -69,21 +94,30 @@ class Miniconf:
"""
setting_topic = f'{self.prefix}/settings/{path}'
response_topic = f'{self.prefix}/response/{path}'
if response_topic in self.inflight:
# TODO use correlation_data to distinguish clients and requests
raise NotImplementedError(
'Only one in-flight message per topic is supported')
# Assign a unique identifier to this update request.
pid = self.request_id
self.request_id += 1
assert pid not in self.inflight, 'Invalid PID encountered'
correlation_data = json.dumps({
'id': self.uuid.hex,
'pid': pid,
})
value = json.dumps(value)
logger.info('Sending %s to "%s"', value, setting_topic)
fut = asyncio.get_running_loop().create_future()
self.inflight[response_topic] = fut
self.inflight[pid] = fut
self.client.publish(setting_topic, payload=value, qos=0, retain=True,
response_topic=response_topic)
response_topic=response_topic,
correlation_data=correlation_data)
return await fut
def main():
""" Main program entry point. """
parser = argparse.ArgumentParser(
description='Miniconf command line interface.',
formatter_class=argparse.RawDescriptionHelpFormatter,
@ -110,15 +144,13 @@ def main():
async def configure_settings():
interface = await Miniconf.create(args.prefix, args.broker)
failures = 0
for kv in args.settings:
path, value = kv.split("=", 1)
for key_value in args.settings:
path, value = key_value.split("=", 1)
code, response = await interface.command(path, json.loads(value))
print(response)
print(f'{path}: {response}')
if code != 0:
failures += 1
return failures
return code
return 0
sys.exit(loop.run_until_complete(configure_settings()))