A Guide to the Kubernetes Networking Model

Kubernetes was built to run distributed systems over a cluster of machines. The very nature of distributed systems makes networking a central and necessary component of Kubernetes deployment, and understanding the Kubernetes networking model will allow you to correctly run, monitor and troubleshoot your applications running on Kubernetes. Networking is a vast space with a lot of mature technologies. For people unfamiliar with the landscape, this can be uncomfortable because most people have existing preconceived notions about networking, and there are a lot of both new and old concepts to understand and fit together into a coherent whole. [Read More]

Infrastructure in an Age of Commodities

Early computers were described using mathematical notation and theoretical constructions, which were then translated by enterprising machinists into custom built calculation engines. The first computer programmers using these machines built applications directly in hardware by plugging together wires and sockets in varying configurations. Even with these short-comings, the value of general purpose computing machines was evident. As companies began to realize the utility of computing, they saw computing as a means for differentiating themselves from their competitors. [Read More]

Recursive Lambda Functions the Y-Combinator

In a purely functional language — like lambda calculus — programs are expressed as nested function calls. Repetition in such an environment requires that nesting of function calls continues until some condition is met. During the repetition, each function passes its result to the next function in the nested chain and this repetition is completed when a test for some condition passes. The repetitive behaviour I’ve just described is recursion: [Read More]

Simplifying Lambda Syntax

Evaluating lambda functions requires using lots of brackets, which can be tedious and are a major source of error for evaluating expressions by hand. To simplify expressions, you can omit brackets when it is clear what the intention of the function is. Particularly, a function application can omit the brackets surrounding each individual parameter and assume the function is applied to the nearest argument. So, instead of expressing a function of three arguments as [Read More]

Introducing Lambda Calculus

Lambda calculus provides some of the foundational structures that functional programming is built from. It therefore seems fitting to start my journey through functional programming with a thorough examination of lambda calculus. This first post will introduce Lambda calculus with references to the book An Introduction to Functional Programming Through Lambda Calculus. Syntax The complete syntax for Lambda calculus is surprisingly small and comprehensible. This section lists the syntax in its entirety, while following sections break the syntax down to explain each part. [Read More]

A Principled Approach to Architecture

A principle is a concept or value that is a guide for behaviour or evaluation. — Wikipedia This post presents a principled approach to architecture. These principles specify what I believe is important about architecture, without diving into any details about how an architect should work. No matter how an architect works day-to-day, by following principles, you can be sure you are providing value in the right areas. [Read More]

Range, Domain, and Codomain

Three common terms come up whenever we talk about functions: domain, range, and codomain. This post clarifies what each of those terms mean. Before we start talking about domain and range, lets quickly recap what a function is: A function relates each element of a set with exactly one element of another set (possibly the same set). Math is Fun That is, a function relates an input to an output. [Read More]

Functional Microservices

One proposed benefit of following a microservice architecture is that each service can be developed, released, and supported independently. In theory this allows development teams to work with less coordination and less overhead, leading to faster development times. In practice, this is difficult to achieve without some guidelines that make it work. The book The Tao of Microservices provides two such guidelines — transport independence, and pattern matching — that create an environment allowing you to compose services. [Read More]

A Functional Programming Learning Plan

I’m documenting my journey from functional neophyte to (hopefully) functional programmer by writing a series of blog posts on the topic. So far I’ve covered what functional programming is and why you would want to learn about it. In this post, I’m going to describe the resources I will be using to become functionally fluent. Although I have previously said I’m learning about functional programming, I should be more specific. [Read More]

Practical Differences Between Functional and Imperative Programming

I previously talked about what functional programming is by comparing it to other programming paradigms. This post expands on that post to talk specifically about practical differences between functional programming and the paradigm most of us are intimately familiar with — imperative. This post is punctuated with some quotes from the book An Introduction to Functional Programming Through Lambda Calculus. It’s worth noting that each of these practical differences are enabled because of the power of referential transparency. [Read More]