A personal ramble

In the beginning

I was born in the late 1960's.

My father (now retired) was a field service engineer in a mainframe company. He built me my first computer from a kit¹ while I will still at primary school.

This computer was based on the Motorola 6800 processor running at 1MHz. After we…


Kubernetes specifics

Part 1 gave an overview of jsonnet syntax and semantics. I’m now going to suggest some ways to use these with kubernetes. These are not hard-and-fast rules, but some patterns you may or may not find useful.

To illustrate this, I’m going to build a complete configuration of the docker…


Basics

In these two articles I’m going to introduce jsonnet as a clean and powerful alternative to helm charts and kustomize for configuring kubernetes resources.

Jsonnet is a general-purpose language for generating JSON, and I needed to play with it for a while to find the best way to apply it…


Have you ever come across Hashicorp’s Vault? It started life as a place to store application “secrets” (e.g. database passwords) securely, without hard-coding them in configuration files. Over time, it has grown into something much more powerful.

There are a number of ways in which users can authenticate themselves to…


In a previous article, I introduced Linstor. Now I’m going to explain some of the concepts needed to use it.

If you’ve read the Linstor user’s guide but are still confused about the relationship between resource-groups, resource-definitions, resources and volumes, then this is for you.

I’m going to leave storage…


Prometheus is a metrics collection system, and its node_exporter exposes a rich range of system metrics.

In this article I’m going to break down the individual metrics for disk I/O. …


With step-by-step guide to deployment under Ubuntu 18.04

When running your own infrastructure, persistent storage has always been a problem for virtual machines and stateful containers.

On the one hand, you have local storage — which means your VMs and containers cannot move without copying their entire disk image.

On the other hand, you have network-attached storage (SANs…


The IO Monad — laid bare

From the Functional Programming illustrated in Python series

But I don’t like Monads!

Monads, Monads, Monads… have you got anything without Monads?

Well, there’s Direct Function Application. That doesn’t have much Monad in it.

The problem is, functions don’t do anything. Sooner or later you’re going to want to write a program which interacts with…


Monads

From the Functional Programming illustrated in Python series

If you’re reading about functional programming, sooner or later you’re going to come across Monads. People seem to find Monads a very difficult topic to understand, so strap yourself in for a bumpy ride.

Err, no. I already covered Monads back in…


Assignment as parameter binding

From the Functional Programming illustrated in Python series

Consider the following sequence of computations, using assignment to temporary variables:

v0 = 4
v1 = v0*v0
v2 = 2*v1
v3 = 1+v2
print(v3)

Can it be done in a purely functional form, without var = expr assignment? It certainly can.

Binding to function parameters

When…

Brian Candler

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store