Deploy a Custom Node.js Application on Microsoft Azure with High Availability and Clustering


If you're a developer working on a Node.js application, you may have wondered about the best way to run it in a production environment. For example:

  • You'd probably like to deploy it in the cloud, to ensure maximum flexibility and optimum resource utilization.
  • You'd want it to be easy to scale and highly available, to make sure that your users have a good experience.
  • To keep things as simple as possible, you'd probably also want to deploy it directly from your Git repository.

Bitnami makes it easy to meet all these requirements. Bitnami's Node.js High-Availability Cluster provides a multi-node Node.js cluster with a shared filesystem and load balancing capabilities. It includes the ability to deploy your Node.js application directly from a Git repository to your cluster, and can be easily integrated with an external MongoDB database, such as Cosmos DB, to enable scalability and geographic redundancy.

Here's the topology of Bitnami's Node.js High-Availability Cluster:

Solution topology

This guide walks you through the process of deploying a custom MEAN (MongoDB, Express, Angular and Node.js) application on Microsoft Azure using Bitnami's Node.js High-Availability Cluster and Cosmos DB service. This guide uses a simple to-do list application as an example, but you can use similar steps to deploy your own Node.js application on Microsoft Azure.

Assumptions and prerequisites

This guide makes the following assumptions:

Step 1: Deploy a Cosmos DB instance

The example Node.js application used in this guide needs a MongoDB database. Since MongoDB is not included with Bitnami's Node.js High-Availability Cluster, you must deploy this separately. The easiest way to do this is with the Azure Cosmos DB service, which provides a scalable, high-availability database in the cloud.

As a first step, go ahead and launch a new Azure Cosmos DB instance, as follows:

  • Browse to the Microsoft Azure management console and log in if needed.
  • From the menu bar on the left, select the "Azure Cosmos DB" item.
  • Click "Add" to add a new Cosmos DB instance.
  • Enter a unique name for your new database instance in the "ID" field and select "MongoDB" as the API.

    Cosmos DB creation

  • In the same tab, create a new resource group by entering a name for it, and choose the location for the server to be deployed. Click "Create" once done.

    Cosmos DB creation

Your new Azure Cosmos DB instance will be deployed, and will appear in the list of instances once online.

Once the instance is online, select the newly-created instance and then select the "Settings -> Connection String" menu item. In the "Read-write Keys" tab, note the database host name, port, username and primary password, as you will need these when deploying your Node.js application to the cluster.

Cosmos DB settings

Step 2: Deploy a Node.js application

The next step is to launch the Bitnami Node.js High-Availability Cluster solution with a Node.js application. The Azure Marketplace lets you do this in just a couple of clicks. Follow these steps:

  • Browse to the Azure Marketplace.
  • Search for the solution by entering the search term "bitnami high availability nodejs" in the search bar at the top.
  • Select the Bitnami Multi-Tier Solution for Node.js High-Availability Cluster in the list of search results.
  • On the description page, review the information and fees. Click the "Get it now" button to proceed and confirm.
  • You will now be redirected to the Microsoft Azure management console. Log in if required.
  • On the solution description page, review the available information and click the "Create" button to proceed.

    Solution initialization

  • In the "Basics" tab, enter an easy-to-remember name for the deployment together. By default, the solution is configured with the URL to Bitnami's sample MEAN application, but you can edit this to reflect the Git repository URL for your own application.

    Solution configuration

    NOTE: Ensure that your application complies with these requirements before proceeding.
    TIP: You can use a private repository by including the username and password in the repository URL, in the format https://USERNAME:PASSWORD@URL.
  • In the same tab, enter the host name, port, username and password for your Cosmos DB instance, a name for the application database and the number of nodes for the cluster. Enter the string ssl=true&replicaSet=globaldb in the "Database connection options" field and create a new resource group by entering a name for it and choosing its location. Click "OK" when done.

    Solution configuration

  • In the "Environment Configuration" tab, enter a password or an SSH public key and choose the size of the virtual machines in the deployment. For more information on available sizes and configurations, refer to the Microsoft Azure pricing sheet.

    Solution environment

    NOTE: To generate a new SSH key pair, you can use PuTTYgen (Windows) or the ssh-keygen command (Linux and Mac OS X). Find instructions on using PuTTYgen and instructions on using ssh-keygen.
  • In the "Summary" tab, verify the chosen settings. Click "OK" to proceed.

    Solution summary

  • In the "Create" tab, review the terms of use and click "Create" to proceed.

Microsoft Azure will now begin spinning up the new cluster. A notification will appear indicating the current status.

Solution deployment

The process can takes up to 40 minutes as the various nodes in the cluster are created and the load balancer is initialized. Once all the necessary elements of the solution been provisioned, you will see a notification and the new instances and related resources will appear in the "Resource groups" section of the Microsoft Azure management console.

Resource group components

You will see that the resource group includes multiple virtual machines (the nodes of the cluster) as well as a load balancer. Selecting the load balancer will display its properties, including its public IP address.

Load balancer IP address

Step 3: Test the deployed application

Enter the load balancer's IP address directly into your browser's address bar. You should now see your application. The image below shows the sample application's welcome page:

Example application

Verify that the application is able to read and write data using the MongoDB database configured earlier. With the example application, enter a new to-do item and it should appear in the list, as shown below:

Example application

NOTE: Find out more about the database configuration variables used by the sample MEAN application.

Your Node.js application is now deployed, configured for use with Cosmos DB, and available for use in high-availability scenarios. For more information, including details about how to configure SSL and connect to the individual nodes of the cluster using SSH, refer to the documentation for Bitnami's Node.js High-Availability Cluster.