Refactor mongo-storage.js (nightscout#6589)

* Refactor `mongo-storage.js` * Use async/await instead of promises * Fixes a bug in the previous implementation where a promise error was not being caught and handled * Code cleanup
tanja3981 · Jan 6, 2021 · 1eaba09 · 1eaba09
1 parent e8d5612
commit 1eaba09
Showing 1 changed file with 60 additions and 66 deletions.
diff --git a/lib/storage/mongo-storage.js b/lib/storage/mongo-storage.js
@@ -1,18 +1,19 @@
 'use strict';
 
-var mongodb = require('mongodb');
-var connection = null;
-var MongoClient = mongodb.MongoClient;
-var mongo = {};
+const MongoClient = require('mongodb').MongoClient;
 
-function init (env, cb, forceNewConnection) {
+const mongo = {
+  client: null,
+  db: null,
+};
 
-  function maybe_connect (cb) {
+function init(env, cb, forceNewConnection) {
 
-    if (connection != null && !forceNewConnection) {
+  function maybe_connect(cb) {
+
+    if (mongo.db != null && !forceNewConnection) {
       console.log('Reusing MongoDB connection handler');
       // If there is a valid callback, then return the Mongo-object
-      mongo.db = connection;
 
       if (cb && cb.call) {
         cb(null, mongo);
@@ -23,76 +24,69 @@ function init (env, cb, forceNewConnection) {
       }
 
       console.log('Setting up new connection to MongoDB');
-      var timeout = 30 * 1000;
-      var options = {
-        reconnectInterval: 10000
-        , reconnectTries: 500
-        , connectTimeoutMS: timeout
-        , socketTimeoutMS: timeout
-        , useNewUrlParser: true
+      const timeout = 10 * 1000;
+      const options = {
+        connectTimeoutMS: timeout,
+        socketTimeoutMS: timeout,
+        useNewUrlParser: true,
+        useUnifiedTopology: true,
       };
 
-      var connect_with_retry = function(i) {
-
-        MongoClient.connect(env.storageURI, options)
-          .then(client => {
-            console.log('Successfully established a connected to MongoDB');
-
-            var dbName = env.storageURI.split('/').pop().split('?');
-            dbName = dbName[0]; // drop Connection Options
-            mongo.db = client.db(dbName);
-            connection = mongo.db;
-            mongo.client = client;
-
-            mongo.db.command({ connectionStatus: 1 }).then(
-              result => {
-                const roles = result.authInfo.authenticatedUserRoles;
-                if (roles.length > 0 && roles[0].role == 'readAnyDatabase') {
-                  console.error('Mongo user is read only');
-                  cb(new Error('MongoDB connection is in read only mode! Go back to MongoDB configuration and check your database user has read and write access.'), null);
-                }
-
-                console.log('Mongo user role seems ok:', roles);
-
-                // If there is a valid callback, then invoke the function to perform the callback
-                if (cb && cb.call) {
-                  cb(null, mongo);
-                }
-              }
-            );
-          })
-          .catch(err => {
-            if (err.message && err.message.includes('AuthenticationFailed')) {
-              console.log('Authentication to Mongo failed');
-              cb(new Error('MongoDB authentication failed! Double check the URL has the right username and password in MONGODB_URI.'), null);
-              return;
-            }
-
-            if (err.name && err.name === "MongoNetworkError") {
-              var timeout = (i > 15) ? 60000 : i * 3000;
-              console.log('Error connecting to MongoDB: %j - retrying in ' + timeout / 1000 + ' sec', err);
-              setTimeout(connect_with_retry, timeout, i + 1);
-              if (i == 1) cb(new Error('MongoDB connection failed! Double check the MONGODB_URI setting in Heroku.'), null);
-            } else {
-              cb(new Error('MONGODB_URI ' + env.storageURI + ' seems invalid: ' + err.message));
-            }
-          });
-
+      const connect_with_retry = async function (i) {
+
+        mongo.client = new MongoClient(env.storageURI, options);
+        try {
+          await mongo.client.connect();
+
+          console.log('Successfully established a connected to MongoDB');
+
+          const dbName = mongo.client.s.options.dbName;
+          mongo.db = mongo.client.db(dbName);
+
+          const result = await mongo.db.command({ connectionStatus: 1 });
+          const roles = result.authInfo.authenticatedUserRoles;
+          if (roles.length > 0 && roles[0].role == 'readAnyDatabase') {
+            console.error('Mongo user is read only');
+            cb(new Error('MongoDB connection is in read only mode! Go back to MongoDB configuration and check your database user has read and write access.'), null);
+          }
+
+          console.log('Mongo user role seems ok:', roles);
+
+          // If there is a valid callback, then invoke the function to perform the callback
+          if (cb && cb.call) {
+            cb(null, mongo);
+          }
+        } catch (err) {
+          if (err.message && err.message.includes('AuthenticationFailed')) {
+            console.log('Authentication to Mongo failed');
+            cb(new Error('MongoDB authentication failed! Double check the URL has the right username and password in MONGODB_URI.'), null);
+            return;
+          }
+
+          if (err.name && err.name === "MongoServerSelectionError") {
+            const timeout = (i > 15) ? 60000 : i * 3000;
+            console.log('Error connecting to MongoDB: %j - retrying in ' + timeout / 1000 + ' sec', err);
+            setTimeout(connect_with_retry, timeout, i + 1);
+            if (i == 1) cb(new Error('MongoDB connection failed! Double check the MONGODB_URI setting in Heroku.'), null);
+          } else {
+            cb(new Error('MONGODB_URI ' + env.storageURI + ' seems invalid: ' + err.message));
+          }
+        }
       };
 
       return connect_with_retry(1);
 
     }
   }
 
-  mongo.collection = function get_collection (name) {
-    return connection.collection(name);
+  mongo.collection = function get_collection(name) {
+    return mongo.db.collection(name);
   };
 
-  mongo.ensureIndexes = function ensureIndexes (collection, fields) {
-    fields.forEach(function(field) {
+  mongo.ensureIndexes = function ensureIndexes(collection, fields) {
+    fields.forEach(function (field) {
       console.info('ensuring index for: ' + field);
-      collection.createIndex(field, { 'background': true }, function(err) {
+      collection.createIndex(field, { 'background': true }, function (err) {
         if (err) {
           console.error('unable to ensureIndex for: ' + field + ' - ' + err);
         }