From 19eedb4335a4e11281d27159c29516fcb43b3c2e Mon Sep 17 00:00:00 2001
From: Ellis Percival <flyte@failcode.co.uk>
Date: Tue, 30 Jan 2018 17:03:40 +0000
Subject: [PATCH] Use hash of topic_prefix as client ID. #24
---
config.schema.yml | 4 ++++
pi_mqtt_gpio/server.py | 12 +++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/config.schema.yml b/config.schema.yml
index 4dca87c..970e884 100644
--- a/config.schema.yml
+++ b/config.schema.yml
@@ -21,6 +21,10 @@ mqtt:
type: string
required: no
default: ""
+ client_id:
+ type: string
+ required: no
+ default: ""
topic_prefix:
type: string
required: no
diff --git a/pi_mqtt_gpio/server.py b/pi_mqtt_gpio/server.py
index aacd322..59d5b86 100644
--- a/pi_mqtt_gpio/server.py
+++ b/pi_mqtt_gpio/server.py
@@ -5,6 +5,7 @@ import sys
import socket
from time import sleep, time
from importlib import import_module
+from hashlib import sha1
import paho.mqtt.client as mqtt
import cerberus
@@ -254,7 +255,16 @@ def init_mqtt(config, digital_outputs):
protocol = mqtt.MQTTv311
if config["protocol"] == "3.1":
protocol = mqtt.MQTTv31
- client = mqtt.Client(protocol=protocol)
+
+ # https://stackoverflow.com/questions/45774538/what-is-the-maximum-length-of-client-id-in-mqtt
+ # TLDR: Soft limit of 23, but we needn't truncate it on our end.
+ client_id = config['client_id']
+ if not client_id:
+ client_id = "pi-mqtt-gpio-%s" % sha1(
+ topic_prefix.encode('utf8')).hexdigest()
+
+ client = mqtt.Client(
+ client_id=client_id, clean_session=False, protocol=protocol)
if config["user"] and config["password"]:
client.username_pw_set(config["user"], config["password"])
--
GitLab