MQTT handle * failed to configure

Describe the bug

When I disable homie discovery the MQTT doesn’t work anymore.

To Reproduce

Steps to reproduce the behavior:

1. Go to settings
2. Click on mqtt
3. Scroll down to homie autodiscovery
4. Click on Enabled (so it gets disabled)
5. See the error in the vacuum log

Vacuum Model

Roborock S50

Valetudo Version

2021.05.0

Expected behavior

Stop homie discovery (since I have no homie, not needed)

Log

[2021-05-26T13:21:20.406Z] [WARN] MQTT handle valetudo/robot/ConsumableMonitoringCapability/brush-side_right failed to configure Error: Handle may only be configured while the MQTT controller is not initialized
    at PropertyMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:160:19)
    at ConsumableMonitoringCapabilityMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:167:29)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async ConsumableMonitoringCapabilityMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/RobotStateNodeMqttHandle.js:30:9)
    at async /snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:162:17
    at async MqttController.reconfigure (/snapshot/Valetudo/backend/lib/mqtt/MqttController.js:452:13)
    at async ConsumableMonitoringCapabilityMqttHandle.findNewConsumables (/snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:153:13)
    at async ConsumableMonitoringCapabilityMqttHandle.refresh (/snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:168:9)
    at async RobotMqttHandle.refresh (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:225:13)
[2021-05-26T13:21:20.409Z] [WARN] MQTT handle valetudo/robot/ConsumableMonitoringCapability/filter-main failed to configure Error: Handle may only be configured while the MQTT controller is not initialized
    at PropertyMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:160:19)
    at ConsumableMonitoringCapabilityMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:167:29)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async ConsumableMonitoringCapabilityMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/RobotStateNodeMqttHandle.js:30:9)
    at async /snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:162:17
    at async MqttController.reconfigure (/snapshot/Valetudo/backend/lib/mqtt/MqttController.js:452:13)
    at async ConsumableMonitoringCapabilityMqttHandle.findNewConsumables (/snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:153:13)
    at async ConsumableMonitoringCapabilityMqttHandle.refresh (/snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:168:9)
    at async RobotMqttHandle.refresh (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:225:13)
[2021-05-26T13:21:20.411Z] [WARN] MQTT handle valetudo/robot/ConsumableMonitoringCapability/sensor-all failed to configure Error: Handle may only be configured while the MQTT controller is not initialized
    at PropertyMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:160:19)
    at ConsumableMonitoringCapabilityMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:167:29)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async ConsumableMonitoringCapabilityMqttHandle.configure (/snapshot/Valetudo/backend/lib/mqtt/handles/RobotStateNodeMqttHandle.js:30:9)
    at async /snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:162:17
    at async MqttController.reconfigure (/snapshot/Valetudo/backend/lib/mqtt/MqttController.js:452:13)
    at async ConsumableMonitoringCapabilityMqttHandle.findNewConsumables (/snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:153:13)
    at async ConsumableMonitoringCapabilityMqttHandle.refresh (/snapshot/Valetudo/backend/lib/mqtt/capabilities/ConsumableMonitoringCapabilityMqttHandle.js:168:9)
    at async RobotMqttHandle.refresh (/snapshot/Valetudo/backend/lib/mqtt/handles/MqttHandle.js:225:13)

[flacjacket]

I can confirm that using the version built here fixes this problem for me.

[Hypfer]

So theres still a race condition somewhere.

@Depau already had some ideas how to fix this properly:

Davide Depau 🏳️‍🌈, [31.05.21 11:24] I think this should need a more careful implementation using this mutex idea but with a proper finite state machine, with some additional internal states that map to homie state “init” but that has a more specific internal meaning

Davide Depau 🏳️‍🌈, [31.05.21 11:24] This way we can have a proper table of allowed state transitions

Davide Depau 🏳️‍🌈, [31.05.21 11:29] Which can be something like

DISCONNECTED → STARTUP → RECONFIGURE → READY reconfigure: READY → RECONFIGURE → READY shutdown: READY → TEARDOWN → DISCONNECTED

with STARTUP being a fake state that is only triggered explicitly by the mqtt controller to otherwise disallow going from disconnected to reconfigure, and TEARDOWN being otherwise identical to RECONFIGURE except any other state transition will fail

Davide Depau 🏳️‍🌈, [31.05.21 11:31] With allowed transitions:

DISCONNECTED: STARTUP STARTUP: RECONFIGURE RECONFIGURE: READY READY: RECONFIGURE, TEARDOWN TEARDOWN: DISCONNECTED

Davide Depau 🏳️‍🌈, [31.05.21 11:32] The advantage of this approach is that while it sounds kinda complex it’s actually extremely easy to implement and extremely hard to mess up being there a finite number of states

Davide Depau 🏳️‍🌈, [31.05.21 11:37] It might make sense though to have an additional error state in case mqtt.js explodes

Davide Depau 🏳️‍🌈, [31.05.21 11:37] Which can only take the shutdown route, then needs to do the reconnection

Davide Depau 🏳️‍🌈, [31.05.21 11:39] I noticed that while mqtt.js technically does handle reconnection, it sometimes will lose subscriptions to topics, so it’s probably better to stick in an error state as long as MQTT.js is not working, then take it down and reconnect