Rethinking database architecture

Originally published 2015-09-02 on the UoB Unix blog The eduroam wireless network has a reliance on a database for the authorization and accounting parts of AAA (authentication, authorization and accounting – are you who you say you are, what access are you allowed, and what did you do while connected). When we started dabbling with database-backed AAA in 2007Continue reading “Rethinking database architecture”

Service availability monitoring with Nagios and BPI

Originally published  2016-11-21 on the UoB Unix blog Several times, senior management have asked Team Wireless to provide an uptime figure for eduroam. While we do have an awful lot of monitoring of systems and services, it has never been possible to give a single uptime figure because it needs some detailed knowledge to make sense ofContinue reading “Service availability monitoring with Nagios and BPI”

Unlocking features in your mk5 Mondeo with FORScan

The Ford Mondeo mk5 (from 2015 onwards) has a number of useful features that are disabled in the factory but can be unlocked using free software and a USB cable, without any special knowledge. Here’s how. You will need a compatible ELM327 cable. There are loads on eBay but it can’t be just any –Continue reading “Unlocking features in your mk5 Mondeo with FORScan”

Merging SELinux policies

Originally published 2016-08-01 on the UoB Unix blog We make extensive use of SELinux on all our systems. We manage SELinux config and policy with the jfryman/selinux Puppet module, which means we store SELinux policies in plain text .te format – the same format that audit2allow generates them in. One of our SELinux policies that covers permissions for NRPE is a large file. When we generateContinue reading “Merging SELinux policies”

Fronting legacy services with Kubernetes

There are many benefits to Kubernetes but what’s not discussed so often is how to migrate your services from their legacy hosting to their new home in Kubernetes. Specifically, I’m looking at the case where you have a single server or a single public IP address and you want to run your services on thatContinue reading “Fronting legacy services with Kubernetes”

The mystery of the Canon A/L switch

Since the 1960s, Canon SLRs have had their power switch confusingly labelled as A and L. This has persisted through many different generations of camera and confused beginners through the ages. But what do the letters A and L stand for? Why not use On and Off, or a red dot and a white dot,Continue reading “The mystery of the Canon A/L switch”