Added db connection retry and docker configuration

.dockerignore

@@ -0,0 +1,4 @@
+node_modules
+npm-debug.log
+Dockerfile
+.dockerignore

.gitignore

@@ -11,3 +11,6 @@ dump.tar.gz
 dump/
 coverage
 *.orig
+.idea
+.idea/*
+*.iml

001_users.js

@@ -0,0 +1,8 @@
+db.createUser({
+    "user": "smack_chat",
+    "pwd": "smack123",
+    "roles": [{
+        "role": "readWrite",
+        "db": "smack_chat"
+    }]
+})

Dockerfile

@@ -0,0 +1,7 @@
+FROM node:10-alpine
+WORKDIR /usr/app
+COPY package.json ./
+RUN npm install
+COPY --chown=node:node . .
+EXPOSE 3030
+CMD [ "npm", "start" ]

docker-compose.yml

@@ -0,0 +1,23 @@
+version: '3.8'
+
+services:
+  mongodb:
+    image: mongo
+    command: --serviceExecutor adaptive
+    ports:
+      - "27017:27017"
+    environment:
+      MONGO_INITDB_ROOT_USERNAME: admin
+      MONGO_INITDB_ROOT_PASSWORD: admin123
+      MONGO_INITDB_DATABASE: smack_chat
+    volumes:
+      - ./001_users.js:/docker-entrypoint-initdb.d/001_users.js:ro
+  mac-chat-api:
+    build: .
+    depends_on:
+      - mongodb
+    ports:
+      - "3005:3005"
+    environment:
+      PORT: 3005
+      MONGODB_URI: "mongodb://smack_chat:smack123@mongodb:27017/smack_chat"

src/db.js

@@ -1,19 +1,34 @@
 import mongoose from 'mongoose';
-import mongodb from 'mongodb';
 import config from './config';
 
 export default callback => {
   let db;
+  let retryCount = 0;
+
+  let connectWithRetry = function() {
+    return mongoose.connect(config.mongoUrl, function (err, database) {
+      console.log("Trying to connect to mongodb...")
+      if (err) {
+        console.log("Waiting for 5 seconds to retry...")
+        if (retryCount < 4) {
+          setTimeout(connectWithRetry, 5000)
+          retryCount++
+          return
+        }
+
+        console.log(err);
+        console.log("Giving up after 5 attempts...")
+        proccess.exit(-1)
+      }
+
+      console.log(config.mongoUrl);
+      // Save database object from the callback for reuse.
+      db = database;
+      console.log("Database connection ready");
+      callback(db);
+    });
+  }
   // Connect to the database before starting the application server.
-  mongoose.connect(config.mongoUrl, function (err, database) {
-    if (err) {
-      console.log(err);
-      process.exit(1);
-    }
-    console.log(config.mongoUrl);
-    // Save database object from the callback for reuse.
-    db = database;
-    console.log("Database connection ready");
-    callback(db);
-  });
+
+  connectWithRetry()
 }