Add logging

.gitignore

@@ -1 +1,3 @@
-src/node_modules
+src/node_modules
+*.log
+src/.env

src/config/main-config.js

@@ -19,6 +19,8 @@
   // *** main dependencies *** //
   const bodyParser = require('body-parser');
   const path = require('path');
+
+  require('dotenv').config();
 
   appConfig.init = function (app, express) {
     app.set('view engine', 'html');

src/helpers/winston.js

@@ -0,0 +1,42 @@
+/**
+ * winston.js - LearnDB
+ *
+ * Kevin Kelly
+ * Data Science & Systems Lab (DASSL)
+ * https://dassl.github.io/
+ * 
+ * (C) 2019- DASSL. ALL RIGHTS RESERVED.
+ * Licensed to others under CC 4.0 BY-SA-NC
+ * https://creativecommons.org/licenses/by-nc-sa/4.0/
+ * 
+ * PROVIDED AS IS. NO WARRANTIES EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
+ *
+ * This file contains the logging functionality
+ */
+
+
+const { createLogger, format, transports } = require('winston');
+
+const {
+  combine, timestamp, printf,
+} = format;
+
+const myFormat = printf(info => `${info.timestamp} ${info.level}: ${info.message}`);
+
+const logger = createLogger({
+  format: combine(
+    timestamp(),
+    myFormat,
+  ),
+  transports: [
+    new transports.File({ filename: `${process.env.PATH_TO_LOGS}/error.log`, level: 'error' }),
+    new transports.File({ filename: `${process.env.PATH_TO_LOGS}/combined.log` }),
+  ],
+});
+
+module.exports = logger;
+module.exports.stream = {
+  write(message) {
+    logger.info(message);
+  },
+};