module.add(user,problem,record)

hydro/service/db.js

@@ -0,0 +1,18 @@
+const Mongo = require('mongodb');
+const options = require('../options');
+let mongourl = 'mongodb://';
+if (options.db.username) mongourl += options.db.username + ':' + options.db.password + '@';
+mongourl += `${options.db.host}:${options.db.port}/${options.db.name}`;
+/**
+ * @type {import('mongodb').Db}
+ */
+let db = null;
+Mongo.MongoClient.connect(mongourl, { useNewUrlParser: true, useUnifiedTopology: true })
+    .then(Database => {
+        db = Database.db(options.db.name);
+        global.bus.emit('connected');
+    });
+
+module.exports = {
+    collection: c => db.collection(c)
+};