In this series' previous post, I discussed serverless services and what Lambda is. Now it's time to show how PHP scripts or even full applications can run on AWS Lambda.

In this post, I explain how to use the Bref runtime and share a repository that contains an example implementation, using the Symfony demo application and Terraform.

Here comes Bref!

Matthieu Napoli, a independent consultant and AWS Serverless Hero, introduced Bref in 2018 and, since then, Bref has thriving, serving more than 40,000,000,000 invocations in July, with a 300% year-over-year growth.

How does Bref work?

Bref is a custom Lambda runtime. Or rather runtimes because in comes in three flavours.

• The first one is designed to run web applications. Bref will catch API Gateway events and convert them in FastCGI requests (the same kind of requests web servers like Apache's httpd or nginx will make to the PHP FPM process) ; it also runs the PHP FPM process for you. This way, your application can go almost totally unmodified (you just need to import the bref/bref composer package). All standard PHP features, such as accessing web request content with the $_POST magic variable, are working.
• The second one is designed to run asynchronously. AWS Lambda functions can process all sort of AWS-generate or custom events. In this case, your PHP function needs to be written with a handler method, that is a PHP callable that takes $event as an argument.
• A third runtime enables to run CLI command, such as php bin/console doctrine:database:create

What sort of application can I run with Bref?

Almost any kind of PHP application kind run with Bref. The documentation offers nice tutorials based on Laravel and Symfony.

Adapting an existing application is quite easy (for instance, Bref provides a nice bref/symfony-messenger library to adapt Symfony Messenger to use SQS rather than its internal bus - reminder: execution environments handle only one request concurrently and are ephemeral, so pushing data to a short-lived internal bus is the recipe for data loss).

The only limitation, really, is if you need extreme reactivity (like 100% of your requests served in 10ms). Indeed, the framework adds 230ms cold start. Even so, as stated in this series' previous article, using provisioned concurrency, you can mitigate this (and if you want to do it without spending too much, Application auto-scaling is your go-to piece of documentation).

How to deploy a Bref-based application

The above-mentioned Symfony/Larevel documentations use the Serverless deployment framework to deploy Bref-powered PHP applications.

Other articles (here and here) explore the CDK as their deployment option.

I'm more of a Terraform fan, so I'm happy to share below a fully working repository using Terraform as the deployment option.

Step-by-step approach to create and deploy a PHP application to Lambda using Terraform

This takes only 8 simple steps

A GitHub repository

In the following GitHub repository, I share a fully-functional set up to deploy this app:

terraform apply

Stay tuned for my next post on How to deploy PHP code on Lambda using the Lambda Web Adapter!