Migrate Express App to DeployApps

In this short guide, you’ll learn how to migrate your Express.js app to DeployApps Cloud in a few simple steps. Before we get started with the tutorial, let’s briefly talk about why you should consider migrating your project to a FaaS platform like DeployApps in the first place.

Why Migrate to a FaaS Platform like DeployApps?

Function-as-a-Service (FaaS) is a serverless model that allows developers to create and execute functions while outsourcing the cloud management aspect to a provider. Many people migrate their applications to reduce operational overhead, scale their applications with ease, and optimize costs. Let’s take a closer look at some of the main benefits of FaaS platforms:

1. Cost Efficiency: With DeployApps’s pricing, you only pay for what you need and always know how much you’ll pay. This lowers your costs significantly compared to traditional servers.

2. Scalability: DeployApps automatically scales your application in response to incoming requests, handling any load without manual intervention.

3. Reduced Maintenance: Moving to DeployApps eliminates the need to manage server infrastructure, allowing you to focus on writing code instead.

4. Out-of-the-box Ecosystem: DeployApps is designed to respond to your needs, making it a natural fit for applications requiring Databases, Cron Jobs, Redis, Queues, Webhooks, etc.

Alright, with that out of the way, let’s get started.

Prerequisites

To start this tutorial, make sure you’ve downloaded and installed the following tools:

• Node.js
• Npm

Note: we recommend you use NVM to manage NodeJs and NPM versions. After installing nvm, you can quickly get any node version by running nvm install <node_version>.

Adapt Your Express App for DeployApps

DeployApps Functions works differently than traditional servers. Instead of listening on a specific port, the functions respond to events. For the Express app, you need to modify the app to act as the entry point for HTTP requests to your function.

Your entire application will be deployed as one function.

Install serverless-http:

serverless-http is a library that wraps your Express app to make it compatible with DeployApps Functions.

npm install serverless-http

Modify the Application Entry Point:

Update your main application file (e.g., app.js or index.js) to use serverless-http. We recommend changing your file extension to mjs if you use the ES Module.

import express from "express";
import Serverless from "serverless-http";

const app = express();

// Your existing Express setup (routes, middleware, etc.)

export const handler = Serverless(app);

Here, the handler will be the entry point for your function.

Configure DeployApps Config File

There are multiple ways to deploy your app to DeployApps. One of the most straightforward approaches is pushing your app to GitHub and activating the DeployApps Github Automation.

You will need a configuration file for this.

name: my-express-app
region: us-east-1
yamlVersion: 2
backend:
  path: ./
  language:
    name: js
    packageManager: npm
  functions:
    - name: express-function
      path: ./
      # change this if you have a different entry point
      entry: index.mjs
      handler: handler
  scripts:
    deploy:
      - npm install

One configuration you need to change is the entry file name of your app.

If you have an entry point tot the app that differs from the index.mjs change it in the configuration file. If you are using TypeScript, add tsc build to the deploy scripts. Another article will provide more insights about this topic.

Deploy Your App using DeployApps’s Github Automation

Now that you have all the configuration needed, push your application to GitHub.

git add .
git commit -m “Configurations for DeployApps Cloud”
git push

Login to the DeployApps Dashboard

Simply go to DeployApps Dashboard and create an account.

Import your project from GitHub

Click Import from GitHub from the dashboard or go to this link . Connect your Github account and give DeployApps access to your repository. Now click on Import and then press on Deploy.

Deploy Your App using DeployApps CLI

Another way to test and deploy your app is by using the DeployApps CLI. First, you have to install the CLI.

npm install genezio -g

Now, you can use genezio local in the root folder of your project to test your app locally.

If everything works fine, you are ready to deploy your project.

genezio deploy

You will be prompted to use a browser to login to the CLI with your DeployApps account.

After the deployment, you will receive one link with your application and another for the dashboard.

Test and Monitor Your App

Congratulations, you have successfully deployed your Express App on DeployApps.

Now, you are ready to monitor your application in production.

Next Steps

Environment Variables If you have environment variables, you can add them from the project folder.

Conclusion

Migrating an Express app to DeployApps offers significant benefits, from cost savings to enhanced scalability . While the process requires some adaptation, the payoff for reduced maintenance and operational efficiency can be substantial.

Happy coding!