Added api gateway and prometheus services

config.json

@@ -44,6 +44,9 @@
   "schema": {
     "services": ["str"],
     "room": "str",
+    "api": {
+      "port": "port?"
+    },
     "mqtt": {
       "url": "str",
       "username": "str",

config/custom-environment-variables.json

@@ -1,5 +1,8 @@
 {
   "room": "ROOM",
+  "api": {
+    "port": "API_PORT"
+  },
   "mqtt": {
     "url": "MQTT_URL",
     "username": "MQTT_USERNAME",

config/default.json

@@ -1,6 +1,9 @@
 {
   "services": [],
   "room": "default-room",
+  "api": {
+    "port": "3000"
+  },
   "mqtt": {
     "url": "mqtt://localhost",
     "username": "",

dependencies.json

@@ -7,5 +7,11 @@
   ],
   "gpio": [
     "onoff@3.1.0"
+  ],
+  "api": [
+    "moleculer-web@0.8.0"
+  ],
+  "prometheus": [
+    "prom-client@11.1.1"
   ]
 }

services/api.service.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const config = require('config');
+
+const ApiGatewayService = require('moleculer-web');
+
+module.exports = {
+    name: 'api',
+
+    mixins: [ApiGatewayService],
+
+    settings: {
+        port: config.get('api.port'),
+
+        routes: [
+            {
+                mappingPolicy: 'restrict',
+                aliases: {
+                    'GET metrics': 'prometheus.metrics'
+                },
+                bodyParsers: {
+                    json: false
+                }
+            }
+        ]
+    }
+};

services/prometheus.service.js

@@ -0,0 +1,16 @@
+const promClient = require('prom-client');
+
+module.exports = {
+    name: 'prometheus',
+
+    actions: {
+        metrics(ctx) {
+            ctx.meta.$responseType = 'text/plain';
+            return promClient.register.metrics();
+        }
+    },
+
+    created() {
+        promClient.collectDefaultMetrics();
+    }
+};