Problem with Mosquitto starting in Local mode

Emoncms Installation
,
1

Hi
I have a problem with mqtt on a new Emoncms installation. e.g.

mosquitto_pub -t 'emon/4/Solar' -m 123 → works ok (executed on the same machine)
mosquitto_pub -h 'pegasus2' -u 'emonpi' -P 'emonpimqtt2016' -t 'emon/4/Solar' -m 345 → Error: Connection refused (when executed either on the same machine or a different pi on the same network).

I tried adding new credentials to passwd using sudo mosquitto_passwd -b passwd pub_client '<different password>' but I still get the same response when I try to use -h.
No problems on my (very old) Emoncms installation - it has no password set!
Found a couple of postings on the forum and tried mosquitto -d command and deleting the mosquitto log but still no joy. Everything else looks normal.

Did I miss something in the install? Any thoughts?
Thanks in advance.

CONFIGURATION DETAILS
Raspberry Pi 3
Raspberry Pi OS with desktop
Release date: May 3rd 2023
System: 64-bit
Kernel version: 6.1
Debian version: 11 (bullseye)

EMONCMS DIY BUILD using the installation script at EmonCMS Install Scripts (reports Emoncms low-write 11.3.20)
In config.ini:
NO emonhub so changed:
install_emonhub=false
install_emoncms_emonpi_modules=false
install_firmware=false
install_emonpilcd=false
install_emonsd=false
install_wifiap=false

and commented out:
declare -A emoncms_emonpi_modules i.e. #declare -A emoncms_emonpi_modules

Not sure what hostname=emonpi is or is used for. The pi hostname was set as Pegasus2 during the OS installation. In config.ini I’ve tried hostname=emonpi and hostname=Pegasus2

/etc/mosquitto/mosquitto.conf includes:
allow_anonymous false
password_file /etc/mosquitto/passwd

2

How did you do the install, and on what OS?

[edit]

That isn’t correct (Mosquitto Username and Password Authentication -Configuration and Testing)

mosquitto_passwd -b passwordfile user password

Try deleting the users and redoing them.

[edit2]
I don’t think you should quote the user and password elements so,

mosquitto_pub -h 192.168.x.x -u emonpi -P emonpimqtt2016

I think the host is the issue

Can you ping that host? If not Mosquitto has no hope of connecting! Nothing to do with passwords.

3

Brian, thanks so much for your reply.

I recall (amongst many other things) I had already tried your suggestion after I reading Steve’s Internet Guide but may have got confused about the combination of settings and their ordering in mosquitto.conf (as described here: per_listener_settings true)

Having done a new trial build of Emoncms last night, I looked at the problem again and I stumbled across a mqtt start up message mentioning ‘starting in local mode only’. It seems that this is the default for my new version of mqtt:
mosquitto version 2.0.11
mosquitto is an MQTT v5.0/v3.1.1/v3.1 broker.

My old (current) version is:
mosquitto version 1.4.10 (build date Tue, 26 Oct 2021 22:24:15 +0200)
mosquitto is an MQTT v3.1 broker.

Adding listener 1883 to mosquitto.conf enables access from remote clients. The following combination of settings in mosquitto.conf now works for me (yeah!).

allow_anonymous false
listener 1883
password_file /etc/mosquitto/passwd

However, my intention for moving from a ‘no password’ to a ‘password’ implementation was to improve security. I’m not sure whether or not including listener 1883 compromises that intention (hmm!).

The password I had added to the password file started with an exclamation mark which seemed to upset mqtt:
-bash: !xyz: event not found
So I put it in quotes - that seemed to solve that problem. The mqtt cli seems to work with or without quotes.

By the way (sorry this is a bit off topic) the Emoncms (OpenEnergyMonitor) install script config.ini includes install_mosquitto_client=true however I don’t believe it does that install. I had to install this separately in order to use client commands.

4

That is interesting. I’m running that version and it doesn’t need that. Cannot see that the package installer has been updated, either.

[email protected]:/var/log/mosquitto $ journalctl -u mosquitto
-- Journal begins at Wed 2023-05-17 11:11:05 BST, ends at Wed 2023-05-17 11:14:12 BST. --
May 17 11:11:42 emonpi systemd[1]: Stopping Mosquitto MQTT Broker...
May 17 11:11:43 emonpi systemd[1]: mosquitto.service: Succeeded.
May 17 11:11:43 emonpi systemd[1]: Stopped Mosquitto MQTT Broker.
May 17 11:11:43 emonpi systemd[1]: mosquitto.service: Consumed 3h 30min 22.081s CPU time.
May 17 11:11:43 emonpi systemd[1]: Starting Mosquitto MQTT Broker...
May 17 11:11:43 emonpi systemd[1]: Started Mosquitto MQTT Broker.

Poorly worded. That isn’t the package mosquitto-clients it is the emoncms PHP MQTT Client (the bit that reads data from the Broker and imports it to emoncms).

5

It is interesting @glyn.hudson @TrystanLea that this has not been raised before. Seems it was introduced with V2 of the package.

6

I just noticed this (bit slow today)

The scripts are tested on the 32Bit OS lite package - not the 64bit Desktop base (as per the documentation).

That is probably where your issues stemmed from. Last time I tried the 64bit image I had other problems with PHP (but they might be solved by other work on installing PHP).