init db/http/mqtt

This commit is contained in:
Blake Blackshear 2020-11-01 08:06:15 -06:00
parent a8964dcc1f
commit 72be6b480d
4 changed files with 208 additions and 471 deletions

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@ -1,472 +1,14 @@
import faulthandler; faulthandler.enable()
import os
import signal
import sys
import traceback
import signal
import cv2
import time
import datetime
import queue
import yaml
import os
import json
import threading
import yaml
import multiprocessing as mp
import subprocess as sp
import numpy as np
import logging
from flask import Flask, Response, make_response, jsonify, request
import paho.mqtt.client as mqtt
from peewee import *
from playhouse.shortcuts import model_to_dict
from playhouse.sqlite_ext import *
from playhouse.flask_utils import FlaskDB
from frigate.video import capture_camera, track_camera, get_ffmpeg_input, get_frame_shape, CameraCapture, start_or_restart_ffmpeg
from frigate.object_processing import TrackedObjectProcessor
from frigate.events import EventProcessor
from frigate.util import EventsPerSecond
from frigate.edgetpu import EdgeTPUProcess
from frigate.config import FRIGATE_CONFIG_SCHEMA
FRIGATE_VARS = {k: v for k, v in os.environ.items() if k.startswith('FRIGATE_')}
CONFIG_FILE = os.environ.get('CONFIG_FILE', '/config/config.yml')
if CONFIG_FILE.endswith(".yml"):
with open(CONFIG_FILE) as f:
CONFIG = yaml.safe_load(f)
elif CONFIG_FILE.endswith(".json"):
with open(CONFIG_FILE) as f:
CONFIG = json.load(f)
CACHE_DIR = CONFIG.get('save_clips', {}).get('cache_dir', '/cache')
CLIPS_DIR = CONFIG.get('save_clips', {}).get('clips_dir', '/clips')
if not os.path.exists(CACHE_DIR) and not os.path.islink(CACHE_DIR):
os.makedirs(CACHE_DIR)
if not os.path.exists(CLIPS_DIR) and not os.path.islink(CLIPS_DIR):
os.makedirs(CLIPS_DIR)
DATABASE = f"sqliteext:///{os.path.join(CLIPS_DIR, 'frigate.db')}"
MQTT_HOST = CONFIG['mqtt']['host']
MQTT_PORT = CONFIG.get('mqtt', {}).get('port', 1883)
MQTT_TOPIC_PREFIX = CONFIG.get('mqtt', {}).get('topic_prefix', 'frigate')
MQTT_USER = CONFIG.get('mqtt', {}).get('user')
MQTT_PASS = CONFIG.get('mqtt', {}).get('password')
if not MQTT_PASS is None:
MQTT_PASS = MQTT_PASS.format(**FRIGATE_VARS)
MQTT_CLIENT_ID = CONFIG.get('mqtt', {}).get('client_id', 'frigate')
# Set the default FFmpeg config
FFMPEG_CONFIG = CONFIG.get('ffmpeg', {})
FFMPEG_DEFAULT_CONFIG = {
'global_args': FFMPEG_CONFIG.get('global_args',
['-hide_banner','-loglevel','panic']),
'hwaccel_args': FFMPEG_CONFIG.get('hwaccel_args',
[]),
'input_args': FFMPEG_CONFIG.get('input_args',
['-avoid_negative_ts', 'make_zero',
'-fflags', 'nobuffer',
'-flags', 'low_delay',
'-strict', 'experimental',
'-fflags', '+genpts+discardcorrupt',
'-rtsp_transport', 'tcp',
'-stimeout', '5000000',
'-use_wallclock_as_timestamps', '1']),
'output_args': FFMPEG_CONFIG.get('output_args',
['-f', 'rawvideo',
'-pix_fmt', 'yuv420p'])
}
GLOBAL_OBJECT_CONFIG = CONFIG.get('objects', {})
WEB_PORT = CONFIG.get('web_port', 5000)
DETECTORS = CONFIG.get('detectors', {'coral': {'type': 'edgetpu', 'device': 'usb'}})
# create a flask app
app = Flask(__name__)
app.config.from_object(__name__)
flask_db = FlaskDB(app)
db = flask_db.database
log = logging.getLogger('werkzeug')
log.setLevel(logging.ERROR)
peewee_log = logging.getLogger('peewee')
peewee_log.addHandler(logging.StreamHandler())
peewee_log.setLevel(logging.DEBUG)
class Event(flask_db.Model):
id = CharField(null=False, primary_key=True, max_length=30)
label = CharField(index=True, max_length=20)
camera = CharField(index=True, max_length=20)
start_time = DateTimeField()
end_time = DateTimeField()
top_score = FloatField()
false_positive = BooleanField()
zones = JSONField()
def init_db():
db.create_tables([Event], safe=True)
class FrigateWatchdog(threading.Thread):
def __init__(self, camera_processes, config, detectors, detection_queue, out_events, tracked_objects_queue, stop_event):
threading.Thread.__init__(self)
self.camera_processes = camera_processes
self.config = config
self.detectors = detectors
self.detection_queue = detection_queue
self.out_events = out_events
self.tracked_objects_queue = tracked_objects_queue
self.stop_event = stop_event
def run(self):
time.sleep(10)
while True:
# wait a bit before checking
time.sleep(10)
if self.stop_event.is_set():
print(f"Exiting watchdog...")
break
now = datetime.datetime.now().timestamp()
# check the detection processes
for detector in self.detectors.values():
detection_start = detector.detection_start.value
if (detection_start > 0.0 and
now - detection_start > 10):
print("Detection appears to be stuck. Restarting detection process")
detector.start_or_restart()
elif not detector.detect_process.is_alive():
print("Detection appears to have stopped. Restarting detection process")
detector.start_or_restart()
# check the camera processes
for name, camera_process in self.camera_processes.items():
process = camera_process['process']
if not process.is_alive():
print(f"Track process for {name} is not alive. Starting again...")
camera_process['camera_fps'].value = 0.0
camera_process['process_fps'].value = 0.0
camera_process['detection_fps'].value = 0.0
camera_process['read_start'].value = 0.0
process = mp.Process(target=track_camera, args=(name, self.config,
self.detection_queue, self.out_events[name], self.tracked_objects_queue, camera_process, self.stop_event))
process.daemon = True
camera_process['process'] = process
process.start()
print(f"Track process started for {name}: {process.pid}")
def main():
stop_event = threading.Event()
# connect to mqtt and setup last will
def on_connect(client, userdata, flags, rc):
print("On connect called")
if rc != 0:
if rc == 3:
print ("MQTT Server unavailable")
elif rc == 4:
print ("MQTT Bad username or password")
elif rc == 5:
print ("MQTT Not authorized")
else:
print ("Unable to connect to MQTT: Connection refused. Error code: " + str(rc))
# publish a message to signal that the service is running
client.publish(MQTT_TOPIC_PREFIX+'/available', 'online', retain=True)
client = mqtt.Client(client_id=MQTT_CLIENT_ID)
client.on_connect = on_connect
client.will_set(MQTT_TOPIC_PREFIX+'/available', payload='offline', qos=1, retain=True)
if not MQTT_USER is None:
client.username_pw_set(MQTT_USER, password=MQTT_PASS)
client.connect(MQTT_HOST, MQTT_PORT, 60)
client.loop_start()
##
# Setup config defaults for cameras
##
for name, config in CONFIG['cameras'].items():
config['snapshots'] = {
'show_timestamp': config.get('snapshots', {}).get('show_timestamp', True),
'draw_zones': config.get('snapshots', {}).get('draw_zones', False),
'draw_bounding_boxes': config.get('snapshots', {}).get('draw_bounding_boxes', True)
}
config['zones'] = config.get('zones', {})
# Queue for cameras to push tracked objects to
tracked_objects_queue = mp.Queue(maxsize=len(CONFIG['cameras'].keys())*2)
# Queue for clip processing
event_queue = mp.Queue()
# create the detection pipes and shms
out_events = {}
camera_shms = []
for name in CONFIG['cameras'].keys():
out_events[name] = mp.Event()
shm_in = mp.shared_memory.SharedMemory(name=name, create=True, size=300*300*3)
shm_out = mp.shared_memory.SharedMemory(name=f"out-{name}", create=True, size=20*6*4)
camera_shms.append(shm_in)
camera_shms.append(shm_out)
detection_queue = mp.Queue()
detectors = {}
for name, detector in DETECTORS.items():
if detector['type'] == 'cpu':
detectors[name] = EdgeTPUProcess(detection_queue, out_events=out_events, tf_device='cpu')
if detector['type'] == 'edgetpu':
detectors[name] = EdgeTPUProcess(detection_queue, out_events=out_events, tf_device=detector['device'])
# create the camera processes
camera_process_info = {}
for name, config in CONFIG['cameras'].items():
# Merge the ffmpeg config with the global config
ffmpeg = config.get('ffmpeg', {})
ffmpeg_input = get_ffmpeg_input(ffmpeg['input'])
ffmpeg_global_args = ffmpeg.get('global_args', FFMPEG_DEFAULT_CONFIG['global_args'])
ffmpeg_hwaccel_args = ffmpeg.get('hwaccel_args', FFMPEG_DEFAULT_CONFIG['hwaccel_args'])
ffmpeg_input_args = ffmpeg.get('input_args', FFMPEG_DEFAULT_CONFIG['input_args'])
ffmpeg_output_args = ffmpeg.get('output_args', FFMPEG_DEFAULT_CONFIG['output_args'])
if not config.get('fps') is None:
ffmpeg_output_args = ["-r", str(config.get('fps'))] + ffmpeg_output_args
if config.get('save_clips', {}).get('enabled', False):
ffmpeg_output_args = [
"-f",
"segment",
"-segment_time",
"10",
"-segment_format",
"mp4",
"-reset_timestamps",
"1",
"-strftime",
"1",
"-c",
"copy",
"-an",
"-map",
"0",
f"{os.path.join(CACHE_DIR, name)}-%Y%m%d%H%M%S.mp4"
] + ffmpeg_output_args
ffmpeg_cmd = (['ffmpeg'] +
ffmpeg_global_args +
ffmpeg_hwaccel_args +
ffmpeg_input_args +
['-i', ffmpeg_input] +
ffmpeg_output_args +
['pipe:'])
config['ffmpeg_cmd'] = ffmpeg_cmd
if 'width' in config and 'height' in config:
frame_shape = (config['height'], config['width'], 3)
else:
frame_shape = get_frame_shape(ffmpeg_input)
config['frame_shape'] = frame_shape
config['take_frame'] = config.get('take_frame', 1)
camera_process_info[name] = {
'camera_fps': mp.Value('d', 0.0),
'skipped_fps': mp.Value('d', 0.0),
'process_fps': mp.Value('d', 0.0),
'detection_fps': mp.Value('d', 0.0),
'detection_frame': mp.Value('d', 0.0),
'read_start': mp.Value('d', 0.0),
'ffmpeg_pid': mp.Value('i', 0),
'frame_queue': mp.Queue(maxsize=2)
}
# merge global object config into camera object config
camera_objects_config = config.get('objects', {})
# get objects to track for camera
objects_to_track = camera_objects_config.get('track', GLOBAL_OBJECT_CONFIG.get('track', ['person']))
# get object filters
object_filters = camera_objects_config.get('filters', GLOBAL_OBJECT_CONFIG.get('filters', {}))
config['objects'] = {
'track': objects_to_track,
'filters': object_filters
}
capture_process = mp.Process(target=capture_camera, args=(name, config,
camera_process_info[name], stop_event))
capture_process.daemon = True
camera_process_info[name]['capture_process'] = capture_process
camera_process = mp.Process(target=track_camera, args=(name, config,
detection_queue, out_events[name], tracked_objects_queue, camera_process_info[name], stop_event))
camera_process.daemon = True
camera_process_info[name]['process'] = camera_process
# start the camera_processes
for name, camera_process in camera_process_info.items():
camera_process['capture_process'].start()
print(f"Camera capture process started for {name}: {camera_process['capture_process'].pid}")
camera_process['process'].start()
print(f"Camera process started for {name}: {camera_process['process'].pid}")
event_processor = EventProcessor(CONFIG, camera_process_info, CACHE_DIR, CLIPS_DIR, event_queue, stop_event, Event)
event_processor.start()
object_processor = TrackedObjectProcessor(CONFIG['cameras'], client, MQTT_TOPIC_PREFIX, tracked_objects_queue, event_queue, stop_event)
object_processor.start()
frigate_watchdog = FrigateWatchdog(camera_process_info, CONFIG['cameras'], detectors, detection_queue, out_events, tracked_objects_queue, stop_event)
frigate_watchdog.start()
def receiveSignal(signalNumber, frame):
stop_event.set()
event_processor.join()
object_processor.join()
frigate_watchdog.join()
for detector in detectors.values():
detector.stop()
for shm in camera_shms:
shm.close()
shm.unlink()
sys.exit()
signal.signal(signal.SIGTERM, receiveSignal)
signal.signal(signal.SIGINT, receiveSignal)
@app.route('/')
def ishealthy():
# return a health
return "Frigate is running. Alive and healthy!"
@app.route('/debug/stack')
def processor_stack():
frame = sys._current_frames().get(object_processor.ident, None)
if frame:
return "<br>".join(traceback.format_stack(frame)), 200
else:
return "no frame found", 200
@app.route('/debug/print_stack')
def print_stack():
pid = int(request.args.get('pid', 0))
if pid == 0:
return "missing pid", 200
else:
os.kill(pid, signal.SIGUSR1)
return "check logs", 200
@app.route('/events')
def events():
events = Event.select()
return jsonify([model_to_dict(e) for e in events])
@app.route('/debug/stats')
def stats():
stats = {}
total_detection_fps = 0
for name, camera_stats in camera_process_info.items():
total_detection_fps += camera_stats['detection_fps'].value
stats[name] = {
'camera_fps': round(camera_stats['camera_fps'].value, 2),
'process_fps': round(camera_stats['process_fps'].value, 2),
'skipped_fps': round(camera_stats['skipped_fps'].value, 2),
'detection_fps': round(camera_stats['detection_fps'].value, 2),
'pid': camera_stats['process'].pid,
'capture_pid': camera_stats['capture_process'].pid,
'frame_info': {
'detect': camera_stats['detection_frame'].value,
'process': object_processor.camera_data[name]['current_frame_time']
}
}
stats['detectors'] = {}
for name, detector in detectors.items():
stats['detectors'][name] = {
'inference_speed': round(detector.avg_inference_speed.value*1000, 2),
'detection_start': detector.detection_start.value,
'pid': detector.detect_process.pid
}
stats['detection_fps'] = round(total_detection_fps, 2)
return jsonify(stats)
@app.route('/<camera_name>/<label>/best.jpg')
def best(camera_name, label):
if camera_name in CONFIG['cameras']:
best_object = object_processor.get_best(camera_name, label)
best_frame = best_object.get('frame')
if best_frame is None:
best_frame = np.zeros((720,1280,3), np.uint8)
else:
best_frame = cv2.cvtColor(best_frame, cv2.COLOR_YUV2BGR_I420)
crop = bool(request.args.get('crop', 0, type=int))
if crop:
region = best_object.get('region', [0,0,300,300])
best_frame = best_frame[region[1]:region[3], region[0]:region[2]]
height = int(request.args.get('h', str(best_frame.shape[0])))
width = int(height*best_frame.shape[1]/best_frame.shape[0])
best_frame = cv2.resize(best_frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
ret, jpg = cv2.imencode('.jpg', best_frame)
response = make_response(jpg.tobytes())
response.headers['Content-Type'] = 'image/jpg'
return response
else:
return "Camera named {} not found".format(camera_name), 404
@app.route('/<camera_name>')
def mjpeg_feed(camera_name):
fps = int(request.args.get('fps', '3'))
height = int(request.args.get('h', '360'))
if camera_name in CONFIG['cameras']:
# return a multipart response
return Response(imagestream(camera_name, fps, height),
mimetype='multipart/x-mixed-replace; boundary=frame')
else:
return "Camera named {} not found".format(camera_name), 404
@app.route('/<camera_name>/latest.jpg')
def latest_frame(camera_name):
if camera_name in CONFIG['cameras']:
# max out at specified FPS
frame = object_processor.get_current_frame(camera_name)
if frame is None:
frame = np.zeros((720,1280,3), np.uint8)
height = int(request.args.get('h', str(frame.shape[0])))
width = int(height*frame.shape[1]/frame.shape[0])
frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
ret, jpg = cv2.imencode('.jpg', frame)
response = make_response(jpg.tobytes())
response.headers['Content-Type'] = 'image/jpg'
return response
else:
return "Camera named {} not found".format(camera_name), 404
def imagestream(camera_name, fps, height):
while True:
# max out at specified FPS
time.sleep(1/fps)
frame = object_processor.get_current_frame(camera_name, draw=True)
if frame is None:
frame = np.zeros((height,int(height*16/9),3), np.uint8)
width = int(height*frame.shape[1]/frame.shape[0])
frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_LINEAR)
ret, jpg = cv2.imencode('.jpg', frame)
yield (b'--frame\r\n'
b'Content-Type: image/jpeg\r\n\r\n' + jpg.tobytes() + b'\r\n\r\n')
app.run(host='0.0.0.0', port=WEB_PORT, debug=False)
object_processor.join()
from frigate.http import create_app
from frigate.models import Event
from frigate.mqtt import create_mqtt_client
class FrigateApp():
def __init__(self, stop: mp.Event):
self.stop = stop
@ -484,14 +26,28 @@ class FrigateApp():
self.config = FRIGATE_CONFIG_SCHEMA(config)
def init_web_server(self):
pass
# TODO: sub in FRIGATE_ENV vars
def init_database(self):
pass
self.db = SqliteExtDatabase(f"/{os.path.join(self.config['save_clips']['clips_dir'], 'frigate.db')}")
models = [Event]
self.db.bind(models)
self.db.create_tables(models, safe=True)
def init_web_server(self):
self.flask_app = create_app(self.db)
def init_mqtt(self):
pass
# TODO: create config class
mqtt_config = self.config['mqtt']
self.mqtt_client = create_mqtt_client(
mqtt_config['host'],
mqtt_config['port'],
mqtt_config['topic_prefix'],
mqtt_config['client_id'],
mqtt_config.get('user'),
mqtt_config.get('password')
)
def start_detectors(self):
pass
@ -510,16 +66,19 @@ class FrigateApp():
def start(self):
self.init_config()
self.init_web_server()
self.init_database()
self.init_web_server()
self.init_mqtt()
self.start_detectors()
self.start_detection_processor()
self.start_frame_processors()
self.start_camera_capture_processes()
self.start_watchdog()
self.flask_app.run(host='0.0.0.0', port=self.config['web_port'], debug=False)
if __name__ == '__main__':
# register stop handler
init_db()
main()
stop_event = mp.Event()
frigate_app = FrigateApp(stop_event)
frigate_app.start()
# main()

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frigate/http.py Normal file
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import os
from flask import (
Flask, Blueprint, jsonify
)
from peewee import SqliteDatabase
from playhouse.shortcuts import model_to_dict
from frigate.models import Event
bp = Blueprint('frigate', __name__)
def create_app(database: SqliteDatabase):
app = Flask(__name__)
@app.before_request
def _db_connect():
database.connect()
@app.teardown_request
def _db_close(exc):
if not database.is_closed():
database.close()
app.register_blueprint(bp)
return app
@bp.route('/')
def is_healthy():
return "Frigate is running. Alive and healthy!"
@bp.route('/events')
def events():
events = Event.select()
return jsonify([model_to_dict(e) for e in events])
# @app.route('/debug/stats')
# def stats():
# stats = {}
# total_detection_fps = 0
# for name, camera_stats in camera_process_info.items():
# total_detection_fps += camera_stats['detection_fps'].value
# stats[name] = {
# 'camera_fps': round(camera_stats['camera_fps'].value, 2),
# 'process_fps': round(camera_stats['process_fps'].value, 2),
# 'skipped_fps': round(camera_stats['skipped_fps'].value, 2),
# 'detection_fps': round(camera_stats['detection_fps'].value, 2),
# 'pid': camera_stats['process'].pid,
# 'capture_pid': camera_stats['capture_process'].pid,
# 'frame_info': {
# 'detect': camera_stats['detection_frame'].value,
# 'process': object_processor.camera_data[name]['current_frame_time']
# }
# }
# stats['detectors'] = {}
# for name, detector in detectors.items():
# stats['detectors'][name] = {
# 'inference_speed': round(detector.avg_inference_speed.value*1000, 2),
# 'detection_start': detector.detection_start.value,
# 'pid': detector.detect_process.pid
# }
# stats['detection_fps'] = round(total_detection_fps, 2)
# return jsonify(stats)
# @app.route('/<camera_name>/<label>/best.jpg')
# def best(camera_name, label):
# if camera_name in CONFIG['cameras']:
# best_object = object_processor.get_best(camera_name, label)
# best_frame = best_object.get('frame')
# if best_frame is None:
# best_frame = np.zeros((720,1280,3), np.uint8)
# else:
# best_frame = cv2.cvtColor(best_frame, cv2.COLOR_YUV2BGR_I420)
# crop = bool(request.args.get('crop', 0, type=int))
# if crop:
# region = best_object.get('region', [0,0,300,300])
# best_frame = best_frame[region[1]:region[3], region[0]:region[2]]
# height = int(request.args.get('h', str(best_frame.shape[0])))
# width = int(height*best_frame.shape[1]/best_frame.shape[0])
# best_frame = cv2.resize(best_frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
# ret, jpg = cv2.imencode('.jpg', best_frame)
# response = make_response(jpg.tobytes())
# response.headers['Content-Type'] = 'image/jpg'
# return response
# else:
# return "Camera named {} not found".format(camera_name), 404
# @app.route('/<camera_name>')
# def mjpeg_feed(camera_name):
# fps = int(request.args.get('fps', '3'))
# height = int(request.args.get('h', '360'))
# if camera_name in CONFIG['cameras']:
# # return a multipart response
# return Response(imagestream(camera_name, fps, height),
# mimetype='multipart/x-mixed-replace; boundary=frame')
# else:
# return "Camera named {} not found".format(camera_name), 404
# @app.route('/<camera_name>/latest.jpg')
# def latest_frame(camera_name):
# if camera_name in CONFIG['cameras']:
# # max out at specified FPS
# frame = object_processor.get_current_frame(camera_name)
# if frame is None:
# frame = np.zeros((720,1280,3), np.uint8)
# height = int(request.args.get('h', str(frame.shape[0])))
# width = int(height*frame.shape[1]/frame.shape[0])
# frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
# ret, jpg = cv2.imencode('.jpg', frame)
# response = make_response(jpg.tobytes())
# response.headers['Content-Type'] = 'image/jpg'
# return response
# else:
# return "Camera named {} not found".format(camera_name), 404
# def imagestream(camera_name, fps, height):
# while True:
# # max out at specified FPS
# time.sleep(1/fps)
# frame = object_processor.get_current_frame(camera_name, draw=True)
# if frame is None:
# frame = np.zeros((height,int(height*16/9),3), np.uint8)
# width = int(height*frame.shape[1]/frame.shape[0])
# frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_LINEAR)
# ret, jpg = cv2.imencode('.jpg', frame)
# yield (b'--frame\r\n'
# b'Content-Type: image/jpeg\r\n\r\n' + jpg.tobytes() + b'\r\n\r\n')
# app.run(host='0.0.0.0', port=WEB_PORT, debug=False)

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frigate/models.py Normal file
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from peewee import *
from playhouse.sqlite_ext import *
class Event(Model):
id = CharField(null=False, primary_key=True, max_length=30)
label = CharField(index=True, max_length=20)
camera = CharField(index=True, max_length=20)
start_time = DateTimeField()
end_time = DateTimeField()
top_score = FloatField()
false_positive = BooleanField()
zones = JSONField()

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frigate/mqtt.py Normal file
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import paho.mqtt.client as mqtt
def create_mqtt_client(host: str, port: int, client_id: str, topic_prefix: str, user: str, password: str):
client = mqtt.Client(client_id=client_id)
def on_connect(client, userdata, flags, rc):
# TODO: use logging library
print("On connect called")
if rc != 0:
if rc == 3:
print ("MQTT Server unavailable")
elif rc == 4:
print ("MQTT Bad username or password")
elif rc == 5:
print ("MQTT Not authorized")
else:
print ("Unable to connect to MQTT: Connection refused. Error code: " + str(rc))
client.publish(topic_prefix+'/available', 'online', retain=True)
client.on_connect = on_connect
client.will_set(topic_prefix+'/available', payload='offline', qos=1, retain=True)
if not user is None:
client.username_pw_set(user, password=password)
client.connect(host, port, 60)
client.loop_start()
return client