🤏 Concis – PHP Serverless Functions Framework (WIP)

Serverless Functions are great, but unfortunately Google Cloud Platform (and other cloud vendors) don't support PHP. Let's fill that gap.

Introduction

Concis [kɔ̃si] is a PHP Serverless Functions Framework that allows you to register functions which will respond to a certain trigger. Triggers have an external origin and are, for example, an incoming HTTP Request or a Cloud Pub/Sub Message Event.

Concis comes with several Providers which provide you with a handful of EventHandlers (and accompanying abstractions / date types) that allow you to easily respond and work with these different types of triggers.

A Concis EventHandler can run on any webserver with PHP, or through one of the Runtime Containers.

Inner Workings: Request & Response

Concis uses symfony/http-foundation internally, utilizing its Symfony\Component\HttpFoundation\Request and Symfony\Component\HttpFoundation\Response classes.

A Concis EventHandler is expected to take a Symfony\Component\HttpFoundation\Request instance as its input, and return a Symfony\Component\HttpFoundation\Response instance which will be sent to the client.

However:

1. Providers can, and should, pre-process the Symfony\Component\HttpFoundation\Request instance and pass their extracted info into their registered Callbacks.

   For example: The CloudStorage Concis EventHandler from the GCPCloud Provider will parse the POSTed JSON-message and build a CloudStorageObject instance from that JSON. It is not the Request object but the CloudStorageObject object that will then be passed into the registered function.

2. If no Response instance is returned from a Concis EventHandler, Concis will try and cast it to a Response:

   1. If a string is returned from a Concis EventHandler, Concis will create a new Response instance with the returned string set as its content and send that.
   2. If no response at all is returned from a Concis EventHandler, Concis will create a new – empty – Response instance and send that.

   Note: By default Response instances have a HTTP Status Code of 200, so that will be used in the two scenarios listed above.

Basic Example

EventHandler Examples

• An EventHandler that responds to a simple HTTP Request:

  $eventHandler = new \Concis\Provider\Generic\Http\EventHandler(function(\Symfony\Component\HttpFoundation\Request $request) {
      $name = $request->query->get('name', 'Concis');
      return new \Symfony\Component\HttpFoundation\Response("Hello, " . htmlspecialchars($name, ENT_QUOTES));
  });

• An EventHandler that responds to a Message being published on Google Cloub Pub/Sub:

  $eventHandler = new \Concis\Provider\GCPCloud\Pubsub\EventHandler(function(string $topic, \Concis\Provider\GCPCloud\Pubsub\Datatype\PubsubMessage $message) {
      $data = $message->getJsonData(true);
      // …
  });

Running the Examples

To run one of these sample EventHandlers we'll use a simple index.php file which we'll upload to a webserver.

$concis = new \Concis\Concis();

$eventHandler = /* … */
$request = Request::createFromGlobals();

$response = $concis->handle(
    $request,
    $eventHandler
);

$response->send();

Alternatively we can use one of the Concis Runtimes

Concis Providers

Out of the box Concis comes with these providers:

• Generic Provider
• Google Cloud Platform Provider

Please refer to each provider's documentation on how to use them.

(Submit a PR with your own Provider to have Concis support more platforms/triggers)

Shorthands

Concis allows EventHandlers to be accessed using a shorthand. That way your code becomes even more concise.

// Without shorthand:
$eventHandler = new \Concis\Provider\Generic\Http\EventHandler(function(\Symfony\Component\HttpFoundation\Request $request) {
	// …
});

// With shorthand:
$eventHandler = \Concis\EventHandler::http(function(\Symfony\Component\HttpFoundation\Request $request) {
	// …
});

Before you can use any of these shorthands, you'll need to register the provider with Concis. For example:

\Concis\Concis::registerProviderShorthands(new \Concis\Provider\Generic\Provider());
\Concis\Concis::registerProviderShorthands(new \Concis\Provider\GCPCloud\Provider());

Concis Runtimes

@TODO

FAQ

Do I need Google Cloud Platform?

No you don't. You can run EventHandlers on any infrastructure.

Can I used Concis without any of the Google Platform integrated triggers?

Yes, you can use the generic HTTP Trigger.

From where the name Concis?

There's a popular PHP Functions Framework for AWS that is named Bref. Concis is a synonym of Bref.

Tests

@TODO 😅

License

Concis is released under the MIT License (MIT). See the enclosed LICENSE for details.