Developing software in the Real World

Using img2lambda to publish your Serverless PHP layer

This interesting tweet by Clare Liguori came to my attention last week: This new img2lambda tool will take the layers of a Docker container and convert them to AWS layers for use in Lambda. I poked around with Clare's example and updated my lambda-php project in order to understand how it works. I also rewrote my runtime's bootstrap to make it clearer. The clever thing from my point of view is that you can build… continue reading.

Serverless PHP on AWS Lamda

Like, Simon Wardley, I think that serverless computing is an interesting space because the billing is granular (pay only when your code executes) and you don't need to worry about maintaining and provisioning servers or containers. So much so, that I maintain the Open Source PHP Runtime for Apache OpenWhisk which is available commercially as IBM Cloud Functions There are other serverless providers, and AWS Lambda is the market leader, but until recently PHP support… continue reading.

Route specific configuration in Slim

A friend emailed me recently asking about route specific configuration in Slim. He wants to be able to set properties when creating the route that he can pick up when the route is matched. The way to do this is using route arguments. I've written about route arguments before in the context of setting default values for a route parameter, but you can also use them to set new data for use later. In this… continue reading.

Migrating to password_verify

I've recently been updating a website that was written a long time ago that has not been touched in a meaningful way in many years. In addition to the actual work I was asked to do, I took the opportunity to update the password hashing routines. This site is so old that the passwords are stored using MD5 hashes and that's not really good enough today, so I included updating to bcrypt hashing with password_hash()… continue reading.

Replacing a built-in PHP function when testing a component

Recently I needed to test part of Slim that uses the built-in PHP functions header() and headers_sent(). To do this, I took advantage of PHP's namespace resolution rules where it will find a function within the same namespace first before finding one with the same name in the global namespace. The idea of how to do this came courtesy of Matthew Weier O'Phinney where this approach is used for similar testing in Zend-Diactoros. This is… continue reading.

Notes for working on the OpenWhisk PHP Runtime

These are some notes for working on the OpenWhisk PHP Runtime, but are probably applicable to the other runtimes too. Setting up I have a clone of the runtimes I'm interested in and core side-by-side in a directory. You then need various tools for development, which are documented here for macOS & Ubuntu in the Prerequites section. Build the container The PHP runtime creates two containers, one for PHP 7.1 and one for PHP 7.2.… continue reading.

Using Fractal as your OpenWhisk API's view layer

When writing an API, it's common to produce an output that conforms to a known media type such as JSON API or HAL, etc. I'm a strong believer that even though I'm writing an API, my application has a view layer. It's not the same as building an HTML page, but you still need to separate out the code that creates the structured output from your model layer. For a couple of APIs that I've… continue reading.

Dependency Injection with OpenWhisk PHP

Any non-trivial PHP applications use various components to do its work, from PDO though to classes from Packagist. It's fairly common in a standard PHP application to use Dependency Injection to configure and load these classes when necessary. How do we do this in a serverless environment such as OpenWhisk? This question comes up because we do not have a single entry point into our application, instead we have one entry point per action. If… continue reading.

Using API Gateway with Serverless & OpenWhisk

As with all serverless offerings OpenWhisk offers an API Gateway to provide HTTP routing to your serverless actions. This provides a number of advantages over web actions, the most significant of which are routing based on HTTP method, authentication and custom domains (in IBM Cloud). Creating routes with the wsk CLI To route to an action using API Gateway, you first need to make your action a web action first:

(You can also use… continue reading.

Using Composer with Serverless & OpenWhisk

Every PHP project I write has dependencies on components from Packagist and my Serverless OpenWhisk PHP projects are no different. It turns out that adding Composer dependencies is trivial. Let's create a simple action that converts a number to it's string form. e.g. 123 becomes one hundred and twenty three. We'll start with our simple ow-php-hello project from my earlier article and add a new function to serverless.yml:

Our handler is n2w.main, so we… continue reading.