feature: add loggers and save logs to DB when using Firebase

database.rules.json

@@ -0,0 +1,6 @@
+{
+  "rules": {
+    ".read": "auth != null",
+    ".write": "auth != null"
+  }
+}

firebase.json

@@ -21,5 +21,8 @@
         "function": "app"
       }
     ]
+  },
+  "database": {
+    "rules": "database.rules.json"
   }
 }

functions/index.js

@@ -2,19 +2,21 @@ const functions = require('firebase-functions');
 const admin = require('firebase-admin')
 
 const { configureApplication } = require('./lib/app')
-// const { createAppLogger } = require('./lib/log-utils')
-// const {
-//   createRouteLogger,
-//   createErrorLogger,
-// } = require('./lib/middlewares')
+const {
+  createRouteLogger,
+  createErrorLogger,
+  createAppLogger,
+} = require('./logger')
 
 admin.initializeApp()
 
 const isDevelopment = process.env.NODE_ENV === 'development'
 
-// const appLogger = createAppLogger({ dev: isDevelopment })
-// const errorLogger = createErrorLogger({ dev: isDevelopment })
-// const routeLogger = isDevelopment ? createRouteLogger({ dev: isDevelopment }) : null
+const db = admin.database()
+
+const appLogger = createAppLogger({ db })
+const errorLogger = createErrorLogger({ db })
+const routeLogger = createRouteLogger({ db })
 const corsOptions = isDevelopment ? {
   origin: 'http://localhost:5000',
 } : null
@@ -22,6 +24,9 @@ const corsOptions = isDevelopment ? {
 const app = configureApplication({
   rateLimitEnabled: false,
   corsOptions,
+  appLogger,
+  errorLogger,
+  routeLogger,
 })
 
 exports.app = functions.https.onRequest(app)

functions/logger.js

@@ -0,0 +1,68 @@
+const winston = require('winston')
+const expressWinston = require('express-winston')
+const Transport = require('winston-transport')
+
+class FirebaseTransport extends Transport {
+  constructor(options) {
+    super(options)
+    this._db = options.db
+  }
+
+  log(info, callback) {
+    try {
+      this._db.ref(`log-${new Date().getTime()}`).set(info)
+      callback(null, info)
+      this.emit('logged', info)
+    } catch (err) {
+      callback(error)
+      this.emit('error', error)
+    }
+
+    return info
+  }
+}
+
+const createRouteLogger = (db) => {
+  return expressWinston.logger({
+    transports: [
+      new FirebaseTransport({ db })
+    ],
+    format: winston.format.combine(
+      winston.format.timestamp(),
+      winston.format.json()
+    ),
+    meta: true,
+    expressFormat: true,
+  })
+}
+
+const createErrorLogger = ({ db }) => {
+  return expressWinston.errorLogger({
+    transports: [
+      new FirebaseTransport({ db })
+    ],
+    format: winston.format.combine(
+      winston.format.timestamp(),
+      winston.format.json()
+    ),
+  })
+}
+
+const createAppLogger = ({ db }) => {
+  return winston.createLogger({
+    format: winston.format.combine(
+      winston.format.timestamp(),
+      winston.format.json()
+    ),
+    transports: [
+      new FirebaseTransport({ db }),
+      new winston.transports.Console(),
+    ]
+  })
+}
+
+module.exports = {
+  createRouteLogger,
+  createErrorLogger,
+  createAppLogger,
+}

functions/package.json

@@ -13,8 +13,6 @@
   },
   "main": "index.js",
   "dependencies": {
-    "firebase-admin": "^9.2.0",
-    "firebase-functions": "^3.11.0",
     "body-parser": "^1.19.0",
     "cheerio": "^1.0.0-rc.3",
     "cors": "^2.8.5",
@@ -22,12 +20,15 @@
     "ejs": "^2.7.1",
     "express": "^4.17.1",
     "express-rate-limit": "^5.0.0",
-    "express-winston": "^4.0.1",
+    "express-winston": "^4.0.5",
+    "firebase-admin": "^9.2.0",
+    "firebase-functions": "^3.11.0",
     "ics": "^2.22.1",
     "request": "^2.88.0",
     "serve-favicon": "^2.5.0",
-    "winston": "^3.2.1",
-    "winston-daily-rotate-file": "^4.2.1"
+    "winston": "^3.3.3",
+    "winston-daily-rotate-file": "^4.2.1",
+    "winston-transport": "^4.4.0"
   },
   "devDependencies": {
     "firebase-functions-test": "^0.2.0"