Azure Functions Custom Handlers

Baller addition (in preview) to Azure Functions:

Azure Functions offers first-class support for a limited number of languages. Now in preview, register custom handlers by providing a lightweight HTTP server in any desired language. Use this new capability to extend the language support for your applications, enabling the use of languages or language versions not provided by Azure Functions.

Upon receiving a request the Functions Host will proxy the call to Custom Handler’s Web Server, which can run any language. Its response will then be used as an output binding payload to the target.

Configuration of the Custom Handler happens using a host.json in the root to tell which process to run:

    "version": "2.0",
    "httpWorker": {
        "description": {
            "defaultExecutablePath": "node",
            "defaultWorkerPath": "server.js"

The contents of your function goes into its own directory. Your code is accompanied by a function.json in which you define the bindings that your function uses. You can bind to queueTrigger for example and output to a queue. HTTP of course is also supported, as per this example:

  "bindings": [
      "type": "httpTrigger",
      "direction": "in",
      "name": "req",
      "methods": ["get", "post"]
      "type": "http",
      "direction": "out",
      "name": "res"

It takes in the Request req and expects a Response res as output.

const express = require("express");
const app = express();



const server = app.listen(PORT, "localhost", () => {
  console.log("Your port is ${PORT}");
  const { address: host, port } = server.address();
  console.log("Example app listening at http://${host}:${port}");

app.get("/hello", (req, res) => {
  res.json("Hello World!");
});"/hello", (req, res) => {
  res.json({ value: req.body });

What I’m currently missing in the documentation and examples repository though is an example using a Dockerfile to say, for example, run PHP code. On Twitter I found this example by Anthony Chu (PM Azure Functions):

The code itself is not available (as a repo) yet, but by looking at the screenshot you can get an idea of how it all comes together. Will do a follow-up post once example PHP code becomes available 😉

Azure Functions custom handlers →
Sample code for Azure Functions custom handlers (GitHub) →

google/cloud-functions-framework – Google Cloud Functions Framework for PHP

google/cloud-functions-framework is an open source FaaS (Function as a Service) Framework for writing portable PHP functions.

An example function looks like this:


use Symfony\Component\HttpFoundation\Request;

function helloHttp(Request $request)
    return "Hello World from PHP HTTP function!" . PHP_EOL;

One can invoke it locally by executing the included router as follows:

export FUNCTION_TARGET=helloHttp
export FUNCTION_SOURCE=index.php
php -S localhost:8080 vendor/bin/router.php

Alternatively you can run it in a Docker container (which you can then deploy to Cloud Run):

docker build . \
    -f vendor/google/cloud-functions-framework/examples/hello/Dockerfile \
    -t my-cloud-function

docker run -p 8080:8080 \
    -e FUNCTION_TARGET=helloHttp \

Installation per Composer:

composer require google/cloud-functions-framework


⚠️ There is a sample Dockerfile included with the repo, but a first glance tells me it needs some polishing as it uses a full blown GAE_RUNTIME Docker base image and directly installs the composer dependencies into the image itself instead of relying on multi-stage builds.

Bref – Serverless PHP Functions on AWS

Bref comes as a Composer package and helps you deploy PHP applications to AWS and run them on AWS Lambda.

Bref uses the Serverless framework to configure and deploy serverless applications. Being the most popular tool, Serverless comes with a huge community, a lot of examples online and a simple configuration format.

After installing an initing Bref …

composer require bref/bref
vendor/bin/bref init

… all you need to do is wrap your code logic into the Bref-provided lambda fn:

require __DIR__.'/vendor/autoload.php';

lambda(function (array $event) {
    // Do anything you want here
    // For example:
    return 'Hello ' . ($event['name'] ?? 'world');

Bref – Serverless PHP made simple →

A Netlify Serverless Function in one Tweet

This is cgi-bin all over again, right?

Running the same Node.js code on Google Cloud Functions, App Engine, and Cloud Run

Google Cloud has a number of options to run your code. We can deploy a function to Cloud Functions, an app to App Engine, or an app with a custom runtime (a Docker container) to Cloud Run.

In this post the same code snippet is deployed to all three Google Cloud Platform features. Locally the Functions Framework is used .

Portable code migrating across Google Cloud’s serverless platforms →