Serverless Express ⎯⎯⎯ This Serverless Framework Component enables you to take existing Express.js apps and deploy them onto cheap, auto-scaling, serverless infrastructure on AWS (specifically AWS HTTP API and AWS Lambda), easily. It's packed with production-ready features, like custom domains, SSL certificates, canary deployments, and costs an average of $0.000003 per request.

[x] Never Pay For Idle - No HTTP requests, no cost. Averages ~$0.000003 per request.
[x] Zero Configuration - All we need is your code, then just deploy (advanced config options are available).
[x] Fast Deployments - Deploy changes to the cloud in seconds.
[x] Realtime Logging - Rapidly develop on the cloud w/ real-time logs and errors in the CLI.
[x] Canary Deployments - Deploy your app gradually to a subset of your traffic overtime.
[x] Custom Domain + SSL - Auto-configure a custom domain w/ a free AWS ACM SSL certificate.
[x] Team Collaboration - Collaborate with your teamates with shared state and outputs.
[x] Built-in Monitoring - Monitor your express app right from the Serverless Dashboard.

Check out the Serverless Fullstack Application for a ready-to-use boilerplate and overall great example of how to use this Component.

Get Started:

Install
Initialize
Deploy
Configure
Dev Mode
Monitor
Remove

Extra:

Architecture
Guides

Install

To get started with this component, install the latest version of the Serverless Framework:

$ npm install -g serverless

After installation, make sure you connect your AWS account by setting a provider in the org setting page on the Serverless Dashboard.

Initialize

The easiest way to start using the express component is by initializing the express-starter template. Just run this command:

$ serverless init express-starter
$ cd express-starter

This will also run npm install for you. You should now have a directory that looks something like this:

|- app.js
|- node_modules
|- package.json
|- serverless.yml

Deploy

Once you have the directory set up, you're now ready to deploy. Just run serverless deploy from within the directory containing the serverless.yml file. Your first deployment might take a little while, but subsequent deployment would just take few seconds. After deployment is done, you should see your express app's URL. Visit that URL to see your new app live.

Note: If you see an internal server error, it probably means you did not run npm install after serverless create. See above for more info.

For more information on what's going on during deployment, you could specify the serverless deploy --debug flag, which would view deployment logs in realtime.

Configure

The Express component is a zero configuration component, meaning that it'll work out of the box with no configuration and sane defaults. With that said, there are still a lot of optional configuration that you can specify.

Here's a complete reference of the serverless.yml file for the express component:

component: express               # (required) name of the component. In that case, it's express.  You will want to pin this to a specific version in production via semantic versioning, like this: express@1.0.10.  Run 'serverless registry express' to see available versions.
name: express-api                # (required) name of your express component instance.
org: serverlessinc               # (optional) serverless dashboard org. default is the first org you created during signup.
app: myApp                       # (optional) serverless dashboard app. default is the same as the name property.
stage: dev                       # (optional) serverless dashboard stage. default is dev.

inputs:
  src: ./                        # (optional) path to the source folder. default is a hello world app.
  memory: 512                    # (optional) lambda memory size.
  timeout: 10                    # (optional) lambda timeout.
  description: My Express App    # (optional) lambda & api gateway description.
  env:                           # (optional) env vars.
    DEBUG: 'express:*'           #            this express specific env var will print express debug logs.
  roleName: my-custom-role-name  # (optional) custom AWS IAM Role name for setting custom permissions.
  traffic: 0.2                   # (optional) traffic percentage to apply to this deployment.
  layers:                        # (optional) list of lambda layer arns to attach to your lambda function.
    - arn:aws:first:layer
    - arn:aws:second:layer
  domain: api.serverless.com     # (optional) if the domain was registered via AWS Route53 on the account you are deploying to, it will automatically be set-up with your Express app's API Gateway, as well as a free AWS ACM SSL Cert.
  vpc:                           # (optional) vpc configuration to apply on the express lambda function
    securityGroupIds:
      - abc
      - xyz
    subnetIds:
      - abc
      - xyz
  region: us-east-2              # (optional) aws region to deploy to. default is us-east-1.

Once you've chosen your configuration, run serverless deploy again (or simply just serverless) to deploy your changes.

Dev Mode

Now that you've got your basic express app up and running, it's time to develop that into a real world application. Instead of having to run serverless deploy everytime you make changes you wanna test, run serverless dev, which allows the CLI to watch for changes in your source directory as you develop, and deploy instantly on save.

To enable dev mode, simply run serverless dev from within the directory containing the serverless.yml file.

Dev mode also enables live streaming logs from your express app so that you can see the results of your code changes right away on the CLI as they happen.

Monitor

Anytime you need to know more about your running express instance, you can run serverless info to view the most critical info. This is especially helpful when you want to know the outputs of your instances so that you can reference them in another instance. You will also see a url where you'll be able to view more info about your instance on the Serverless Dashboard.

It also shows you the status of your instance, when it was last deployed, and how many times it was deployed. To dig even deeper, you can pass the --debug flag to view the state of your component instance in case the deployment failed for any reason.

Remove

If you wanna tear down your entire express infrastructure that was created during deployment, just run serverless remove in the directory containing the serverless.yml file. The express component will then use all the data it needs from the built-in state storage system to delete only the relavent cloud resources that it created.

Just like deployment, you could also specify a --debug flag for realtime logs from the express component running in the cloud.

Architecture

This is the AWS serverless infrastructure that is created by this Component:

[x] AWS HTTP API - The API Gateway which receives all requests and proxies them to AWS Lambda.
[x] AWS Lambda - A single AWS Lambda function runs your Express.js application.
[x] AWS IAM - An AWS IAM role is automatically created, if you do not provide a custom one.
[x] AWS Route53 - If you enter a domain input and the domain already exists on your AWS account, a Route53 hosted zone will be created and integrated into your API Gateway.
[x] AWS ACM SSL Certificate - If you enter a domain input and the domain already exists on your AWS account, a free AWS ACM SSL certificate will be created.

Guides

Setting Up A Custom Domain & SSL Certificate

The Express Component can easily set up a custom domain and free SSL certificate for you.

First, register your custom domain via Route53 on the AWS Acccount you are deploying to.

Next, add the domain to the domain in inputs in serverless.yml, like this:

inputs:
  src: ./
  domain: serverlessexpress.com

You can also use a subdomain:

inputs:
  src: ./
  domain: express.component-demos.com

Run serverless deploy.

Keep in mind, it will take AWS CloudFront and AWS Route53 and DNS up to 24 hours to propagate these changes and make your custom domain globally accessible. However, with recent AWS CloudFront speed increases, your domain should be accessible within ~20 minutes.

Setting up domains registered outside of AWS

If your domain is not on AWS Route53, you will have to set this up manually because the component does not have access to your registrar. Here are the general steps involved:

Create an AWS ACM certificate for your domain. Make sure you set the "Additional Names" field to *.yourdomain.com as well to include all subdomains as well.
After you create the certificate, it should be in a PENDING_VALIDATION status. Now you will need to validate your domain. We suggest you follow the DNS steps by adding the validation CNAME record you see on

Express

Install / Use

README