Mark Hansen - Mark Hansen

Laptop as Home Server with Ansible

Here's how I used a trusty old Thinkpad T510 laptop as a home server. This is mostly notes for myself, but perhaps it'll be useful to others too. The server isn't doing much right now; just running my home weather and power monitoring Grafana Dashboards Server Prometheus real-time monitoring database

Visualizations

Automating NZ Wireless Map with Google Cloud Run

Almost a year ago, I promised a post detailing how I process NZ Wireless Map's data to keep it fresh. Here it is: Recap: The ProblemNZ Wireless Map is a map of the point-to-point wireless links in New Zealand, using data pulled from the NZ spectrum regulator, who host a

Books

Reading Challenge 2021 [Reviews 1-4]

Previously: Read Harder Challenge 2020 Retrospective. I'm starting BookRiot's Read Harder 2021 Challenge, trying to read a more diverse set of genres and authors, to hear stories outside my normal. I've read four books on the challenge so far: time to review them! Reviews ordered below from favourite to least-liked.

Books

Read Harder Challenge 2020 Retrospective

My retrospective of BookRiot's Read Harder Challenge 2020. BackgroundI enjoy reading: reading lets me imagine what life is like for different people, lets me hear stories different from my usual life, lets me learn and grow from the author's experiences. I keep a list of books I've read. A few

Cyling

Cycling Windsor to Ourimbah

We recently cycled a 128km two-day trip from Windsor Station, in Sydney's far northwest, to Ourimbah Station, in the Central Coast, mostly following the banks of the Hawkesbury River. Hopefully these trip notes are useful to anyone considering the ride. Full route map. Day 1 in blue, Day 2 in

Visualizations

Visualising Sydney/NSW Rents

NSW Government Fair Trading holds bonds for all residential tenancies in NSW, and every month they publish Excel spreadsheets of weekly rent, broken down by postcode, bedrooms, property type (house/flat/townhouse), and lodgement date. The data is licensed under Creative Commons Attribution. I converted and imported this data into

Cyling

Hunter Valley Cycle Tour

My partner & I just finished an 8-day, 250 km bicycle tour in the Hunter Valley, north of Sydney. Full route map. Anticlockwise starting and ending in Maitland.We tried to research Hunter Valley cycling before going, but couldn't find much information online. We're hoping this can be a useful

Electricity Monitoring with Tasmota & Prometheus

This post is about graphing power draw of appliances using a smart plug, Prometheus time-series database, and Grafana dashboards. First, you'll need a smart plug that you've flashed to the Tasmota open source firmware. In Part 1, I re-flashed some cheap Kogan smart plugs. Build Tasmota with Prometheus enabledTasmota has

Flashing Kogan Smart Plugs

Edit Jan 2021: A reader informs me that: Unfortunately, it seems that the newer firmware from factory is now encrypted and the Tuya Convert method no longer works as per https://github.com/ct-Open-Source/tuya-convert/wiki/Collaboration-document-for-PSK-Identity-02Oh well! It was good while it lasted. Original post below: I re-flashed some

NSW Police Should Not Have Sonic Weapons

[This is a letter I've sent to my NSW MP. Perhaps you could send something similar to your MP?] I'm writing asking for assistance to take these mass punishment devices away from police. On Jun 12, at Hyde Park, NSW Police threatened the use of, and then tested, the euphemistically

Documentation

How are popular open source projects documented?

This is a survey of the state of the art in developer documentation - how the most popular open source tools manage their documentation. I'm currently updating the documentation of an open source tool, and I thought I'd start with surveying the prior art of how successful projects are doing

Security

2FA for .nz Domains

There aren't many .nz domain name registrars supporting Two Factor Authentication.

Terminal

An Argument for Auto-Starting Tmux

changing the default from tmux opt-in to opt-out has cumulatively saved me days of time over the last few years

TP-Link VR1600v Router Doubled my Ping

This is pretty weird! I'm writing this up in case others are struggling with this, so something comes up when they Google what's wrong. The TP-Link Archer VR1600v Modem Router seems to double my latency pinging Sydney sites from 6-8ms to 12-16ms compared with my previous Huawei HG630 Gateway. This

Automating Mac Maintenance with Ansible

I run a bunch of software on my Macbook. I'd like to keep that software up to date and patched, so it doesn't have security vulnerabilities. Trouble is, I install it from lots of places: Random websites (for the most part)Homebrew (for most commandline programs)Homebrew Cask (a somehow

Air Quality

Ansible for Raspberry Pis

During the recent Australian bushfire season, I'd been administering four Raspberry Pis around the house for air quality monitoring. The usual progression of sysadminning automation followed: SSH'ing in and running commands by handGradually making shellscripts for some common tasksCopy/pasting the shellscripts to set different parameters for different PisRunning those

Cyling

Sydney Cycling Communities and Maps

With so many people picking up cycling lately, I thought I'd write up the resources that I've found over the years that have helped me. When I started I was following poor routes and getting frustrated, but I found a bunch of resources that made route planning a lot easier,

Air Quality

Review: Kaiterra Laser Egg Air Quality Monitor

I bought a Kaiterra Laser Egg Air Quality Sensor from their international store for 148USD, or 225AUD. PortabilityIt's great that you can charge it up and take it around the house. I'm looking forward to using this to find gaps in our home's sealing. The VolumeI would have liked to

Visualizations

My 8-year Attempt to Automate NZ Wireless Map

The almost-decade-long process I went through trying, and failing, to automate updating the data shown on NZ Wireless Map.

Air Quality

Building a Raspberry Pi Home Air Quality Sensor

In Part 1: Build or Buy, I discussed the various pre-built Air Quality systems you could buy: sensors connected to databases that allow you to graph the data coming out. I ended up building my own system to monitor air quality. PMS5003 SensorPMS5003 Air Quality SensorI bought some PMS5003 sensors

Air Quality

Indoor Air Quality Sensor: Build or Buy?

Australia's on fire, and smoke is inundating our cities and homes, causing terrible air quality, often over 10x hazardous levels. I'd like to measure how bad the air quality is in my home, when it looks like this outside: Goals Graph air quality in my home over time, so I

Visualizations

NSW Executor Fees Visualisation

or: bargain-hunting, even beyond the grave When setting up a will, you must nominate an executor to distribute your assets. It's a nontrivial task with some legal liability, so it seems most common to nominate an organization to do it for you. There are a variety of organizations that'll execute

Book Review: First They Killed My Father

Loung Ung, First they Killed My Father, 2006. 238 pages. Before travelling to Cambodia, I wanted to learn a bit about their recent history - what happened during the Khmer Rouge regime. This book was highly recommended as a memoir of someone who lived through those years. The Statistics 1975:

Losing the Arms Race

Another month, another headling-grabbing bug: "Patch ASAP: Tons of Linux apps can be hijacked by evil DNS servers, man-in-the-middle miscreants" - The Register "Patch now! Unix bug puts Linux systems at risk" - InfoWorld "Extremely severe bug leaves dizzying number of software and devices vulnerable&

Read-along: Berkeley DB

In this post, I read along with the 1999 Berkeley DB USENIX paper. Berkeley DB as a tiny (175KB) embedded key-value filesystem-backed database. Berkeley DB lets you associate byte-string keys to byte-string values, with no practical limits on the size of these keys or values. You can get, set, loop