Discovery MQTT service registered in HA

[mik-laj]

Hello,

It would be great if this extension automatically retrieved the credentials available in HA similarly to the Zigbee2MQTT extension.

This can be done using the Homeassistant Services API: Here are related docs:
https://developers.home-assistant.io/docs/add-ons/communication#services-api

This requires two changes:

1. We need to define the services field in the config.json file.
   Here is example code from Z2M addon:
   https://github.com/zigbee2mqtt/hassio-zigbee2mqtt/blob/f8e493f2c4610d6f062b6d1082e18f3d53e8d5a6/zigbee2mqtt/config.json#L10-L12
   Here are docs about services property:
   https://developers.home-assistant.io/docs/add-ons/configuration#optional-configuration-options

2. In entrypoint we need to read the necessary credentials and configure environment variables.
   Here is example code from Z2M addon:
   https://github.com/zigbee2mqtt/hassio-zigbee2mqtt/blob/f8e493f2c4610d6f062b6d1082e18f3d53e8d5a6/common/rootfs/docker-entrypoint.sh#L94-L102

Let me know if you're interested and I'll make a contribution.

[Smeagolworms4]

I don't have time to take care of the feature but if you make me a PR with the modification I'm interested

[mik-laj]

For now, I have the following code:
Dockerfile

FROM ghcr.io/home-assistant/i386-base:3.21 as ha-base

FROM smeagolworms4/mqtt-explorer

COPY --from=ha-base /usr/lib/bashio /usr/lib/bashio

RUN apk add jq bash curl

RUN ln -s /usr/lib/bashio/bashio /usr/bin/bashio
# ENV LOG_LEVEL=8

COPY ./entrypoint.sh /entrypoint.sh

entrypoint.sh

#!/usr/bin/env bashio

if [ -n "${INITIAL_CONFIG}" ] && [ ! -f "$CONFIG_PATH/settings.json" ]; then
    echo "${INITIAL_CONFIG}" > "$CONFIG_PATH/settings.json"
fi
if [ ! -f "$CONFIG_PATH/settings.json" ]; then
    echo '{"ConnectionManager_connections": {}}' > "$CONFIG_PATH/settings.json"
fi

if bashio::var.has_value "$(bashio::services 'mqtt')"; then
    if bashio::var.true "$(bashio::services 'mqtt' 'ssl')"; then
        export MQTT_ENCRYPTION="true"
    else
        export MQTT_ENCRYPTION="false"
    fi
    export MQTT_HOST="$(bashio::services 'mqtt' 'host')"
    export MQTT_PORT="$(bashio::services 'mqtt' 'port')"
    export MQTT_USER="$(bashio::services 'mqtt' 'username')"
    export MQTT_PASSWORD="$(bashio::services 'mqtt' 'password')"
    cp  "$CONFIG_PATH/settings.json"  "$CONFIG_PATH/settings.backup.json"

    cat "$CONFIG_PATH/settings.backup.json" | jq '.ConnectionManager_connections += {
        "f69723c3-4fcd-4bd9-a63d-c81864946931": {
            "configVersion": 1,
            "certValidation": true,
            "clientId": "mqtt-explorer-52dfac40",
            "id": "f69723c3-4fcd-4bd9-a63d-c81864946931",
            "name": "homeassistant",
            "encryption": $MQTT_ENCRYPTION,
            "subscriptions": [
                {
                "topic": "#",
                "qos": 0
                },
                {
                "topic": "$SYS/#",
                "qos": 0
                }
            ],
            "type": "mqtt",
            "host": $MQTT_HOST,
            "port": $MQTT_PORT,
            "protocol": "mqtt",
            "changeSet": {
                "password": $MQTT_PASSWORD
            },
            "username": $MQTT_USER,
            "password": $MQTT_PASSWORD
            }
    }' \
    --arg MQTT_ENCRYPTION "${MQTT_ENCRYPTION}" \
    --arg MQTT_HOST "${MQTT_HOST}" \
    --arg MQTT_PORT "${MQTT_PORT}" \
    --arg MQTT_USER "${MQTT_USER}" \
    --arg MQTT_PASSWORD "${MQTT_PASSWORD}" \
        > "$CONFIG_PATH/settings.json"
fi


cat "$CONFIG_PATH/settings.json" | jq .
exec "$@"