Try to reconnect to MQTT broker if disconnected

[Jalle19]

Woke up and the MQTT part didn't work at all. Unfortunately I couldn't get at the logs since I have HTTP request spamming the log, and Home Assistant doesn't seem to store (or at least expose) logs that far back.

[tomrosenback]

This should be handled by the MQTT library, check https://github.com/mqttjs/MQTT.js#about-reconnection

[Jalle19]

It sounds like that section is only relevant when using the library from a browser context (in which case WebSockets are involved). I'll have to do some testing.

[tomrosenback]

mqttClient.on('connect', async () => {
    console.log("MQTT broker connected")
})

mqttClient.on('close', async () => {
    console.log('MQTT broker closed connection')
    
    setTimeout(async () => {
        console.log('Reconnect to MQTT broker')
        client.reconnect()
    }, 5000)
})

Made some quick and dirty tests locally, above at least works when the broker dissappears after the first successful connectAsync. Does not handle the failed connection in the catch part.

[Jalle19]

That probably on tries to reconnect once?

[Jalle19]

mqttjs/MQTT.js#101 (comment) maybe this is the actual issue?

[tomrosenback]

That probably on tries to reconnect once?

Could you please elaborate? mqttClient.on('close'... happens everytime a reconnect fail.

[tomrosenback]

mqttjs/MQTT.js#101 (comment) maybe this is the actual issue?

You are refering to the comment about the fact that after the client has reconnected it don´t subscribe to the topics previously subscribed? I thought you had problems also with the publishing?

Also it seems the MQTT really does default try to reconnect every second. https://github.com/mqttjs/MQTT.js/blob/7ec4b8fd602e220f50693cb83f082dab764ed3f2/lib/client.js#L29

[Jalle19]

Yeah, maybe I had some other issue, it's hard to tell since I never could get the complete log :/

[tomrosenback]

Noticed after updating to 1.1.0 of the HA addon https://github.com/Jalle19/home-assistant-addon-repository which uses 2.1.0 of eda-modbus-bridge the MQTT connection failed on startup of the addon causing MQTT connection remaining disconnected until manual restart of addon. Restarting the addon manually helped in this case.