feat: add MQTT sensor publishing for Home Assistant

Adds a new s6 service (svc-foldingathome-mqtt) that polls the FAH 8 API
on port 7396 every 30 seconds and publishes 4 sensors to HA via MQTT
autodiscovery: Status, PPD, Work Unit Progress, and Credit estimate.

Requires the Mosquitto broker add-on; declared as mqtt:want so the
add-on remains functional without it.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -30,6 +30,7 @@ RUN \
         curl \
         jq \
         libexpat1 \
+        mosquitto-clients \
         netcat-openbsd && \
     echo "**** install foldingathome ****" && \
     if [ "${BUILD_ARCH}" = "aarch64" ]; then \

config.yaml

@@ -13,6 +13,8 @@ ports_description:
   7396/tcp: Folding@home Web Interface
 map:
   - config:rw
+services:
+  - mqtt:want
 options:
   user: ""
   team: "247478"

root/etc/s6-overlay/s6-rc.d/svc-foldingathome-mqtt/run

@@ -0,0 +1,99 @@
+#!/usr/bin/with-contenv bashio
+# shellcheck shell=bash
+
+FAH_API="http://localhost:7396/api"
+POLL_INTERVAL=30
+STATE_TOPIC="foldingathome/state"
+DISCOVERY_PREFIX="homeassistant"
+
+# Abort cleanly if MQTT service is not available
+if ! bashio::services.mqtt; then
+    bashio::log.info "MQTT not available — skipping sensor publishing. Install the Mosquitto broker add-on to enable HA sensors."
+    exec sleep infinity
+fi
+
+MQTT_HOST=$(bashio::services.mqtt 'host')
+MQTT_PORT=$(bashio::services.mqtt 'port')
+MQTT_USER=$(bashio::services.mqtt 'username')
+MQTT_PASS=$(bashio::services.mqtt 'password')
+UNIQUE_ID="foldingathome_$(hostname | tr -cd '[:alnum:]_')"
+
+mqtt_publish() {
+    mosquitto_pub \
+        -h "$MQTT_HOST" -p "$MQTT_PORT" \
+        -u "$MQTT_USER" -P "$MQTT_PASS" \
+        -t "$1" -m "$2" -r -q 1
+}
+
+publish_discovery() {
+    local device
+    device=$(jq -n \
+        --arg id "$UNIQUE_ID" \
+        '{identifiers: [$id], name: "Folding@home", model: "FAH 8", manufacturer: "foldingathome.org"}')
+
+    declare -A sensors
+    sensors=(
+        ["status"]='{"name":"Folding@home Status","value_template":"{{ value_json.status }}","icon":"mdi:dna"}'
+        ["ppd"]='{"name":"Folding@home PPD","value_template":"{{ value_json.ppd }}","unit_of_measurement":"PPD","icon":"mdi:speedometer","state_class":"measurement"}'
+        ["progress"]='{"name":"Folding@home Progress","value_template":"{{ value_json.progress }}","unit_of_measurement":"%","icon":"mdi:progress-clock","state_class":"measurement"}'
+        ["credit"]='{"name":"Folding@home Credit","value_template":"{{ value_json.credit }}","unit_of_measurement":"points","icon":"mdi:star","state_class":"total_increasing"}'
+    )
+
+    for key in "${!sensors[@]}"; do
+        local config
+        config=$(echo "${sensors[$key]}" | jq \
+            --arg uid "${UNIQUE_ID}_${key}" \
+            --arg topic "$STATE_TOPIC" \
+            --argjson device "$device" \
+            '. + {unique_id: $uid, state_topic: $topic, device: $device}')
+        mqtt_publish "${DISCOVERY_PREFIX}/sensor/${UNIQUE_ID}_${key}/config" "$config"
+    done
+
+    bashio::log.info "HA sensor discovery published (${#sensors[@]} sensors)"
+}
+
+# Wait for FAH API to become ready
+bashio::log.info "Waiting for Folding@home API on port 7396..."
+until curl -sf "${FAH_API}/info" > /dev/null 2>&1; do
+    sleep 5
+done
+bashio::log.info "Folding@home API ready — starting MQTT sensor publisher"
+
+publish_discovery
+
+while true; do
+    UNITS=$(curl -sf "${FAH_API}/units" 2>/dev/null || echo "[]")
+    UNIT_COUNT=$(echo "$UNITS" | jq 'length')
+
+    if [ "$UNIT_COUNT" -gt 0 ]; then
+        RAW_STATE=$(echo "$UNITS" | jq -r '.[0].state // "unknown"')
+        case "$RAW_STATE" in
+            RUN)      STATUS="Running" ;;
+            PAUSE)    STATUS="Paused" ;;
+            FINISH)   STATUS="Finishing" ;;
+            ASSIGN)   STATUS="Assigning" ;;
+            DOWNLOAD) STATUS="Downloading" ;;
+            SEND)     STATUS="Sending" ;;
+            *)        STATUS="Idle" ;;
+        esac
+        PPD=$(echo "$UNITS" | jq '[.[].ppd // 0] | add // 0 | round')
+        PROGRESS=$(echo "$UNITS" | jq '.[0].progress // 0 | . * 100 | round')
+        CREDIT=$(echo "$UNITS" | jq '[.[].credit // 0] | add // 0 | round')
+    else
+        STATUS="Idle"
+        PPD=0
+        PROGRESS=0
+        CREDIT=0
+    fi
+
+    PAYLOAD=$(jq -n \
+        --arg status "$STATUS" \
+        --argjson ppd "$PPD" \
+        --argjson progress "$PROGRESS" \
+        --argjson credit "$CREDIT" \
+        '{status: $status, ppd: $ppd, progress: $progress, credit: $credit}')
+
+    mqtt_publish "$STATE_TOPIC" "$PAYLOAD"
+
+    sleep "$POLL_INTERVAL"
+done

root/etc/s6-overlay/s6-rc.d/svc-foldingathome-mqtt/type

@@ -0,0 +1 @@
+longrun