A toy remote login server

Hello! The other day we talked about what happened when you press a key in your terminal. As a followup, I thought it might be fun to implement a program that’s like a tiny ssh server, but without the security. You can find it on github here, and I’ll explain how it works in this blog post. the goal: “ssh” to a remote computer Our goal is...

3w

What happens when you press a key in your terminal?

I’ve been confused about what’s going on with terminals for a long time. But this past week I was using xterm.js to display an interactive terminal in a browser and I finally thought to ask a pretty basic question: when you press a key on your keyboard in a terminal (like Delete, or Escape, or a), which bytes get sent? As usual we’ll answer...

4w

Monitoring tiny web services

Hello! I’ve started to run a few more servers recently (nginx playground, mess with dns, dns lookup), so I’ve been thinking about monitoring. It wasn’t initially totally obvious to me how to monitor these websites, so I wanted to quickly write up what how I did it. I’m not going to talk about how to monitor Big Serious Mission Critical websites...

Jul 2022

Notes on running containers with bubblewrap

Hello! About a year ago I got mad about Docker container startup time. This was because I was building an nginx playground where I was starting a new “container” on every HTTP request, and so for it to feel reasonably snappy, nginx needed to start quickly. Also, I was running this project on a pretty small cloud machine (256MB RAM), a small CPU,...

Jun 2022

sqlite-utils: a nice way to import data into SQLite for analysis

Hello! This is a quick post about a nice tool I found recently called sqlite-utils, from the tools category. Recently I wanted to do some basic data analysis using data from my Shopify store. So I figured I’d query the Shopify API and import my data into SQLite, and then I could make queries to get the graphs I want. But this seemed like a lot...

May 2022

Pages that didn't make it into "How DNS Works"

Hello! A couple weeks ago I released a new zine called How DNS Works. When I started writing that zine (in, uh, January 2021), I originally had in mind a broader zine on “everything you need to know to own a domain”. So it had a bunch of pages on domain registration, TLS, and email. At the time I thought “I can just explain DNS in like 5 pages,...

May 2022

New zine: How DNS Works!

Hello! On Thursday we released a new zine about one of my favourite computer systems: DNS! You can get it for $12 here: https://wizardzines.com/zines/dns, or get an 11-pack of all my zines here. Here’s the cover and table of contents: why DNS? I wanted to write about DNS for three reasons: DNS is everywhere! You basically...

Apr 2022

A list of new(ish) command line tools

Hello! Today I asked on twitter about newer command line tools, like ripgrep and fd and fzf and exa and bat. I got a bunch of replies with tools I hadn’t heard of, so I thought I’d make a list here. A lot of people also pointed at the modern-unix list. replacements for standard tools ripgrep, ag, ack (grep) exa, lsd (ls) mosh (ssh) bat...

Apr 2022

Implementing a toy version of TLS 1.3

Hello! Recently I’ve been thinking about how I find it fun to learn computer networking by implementing working versions of real network protocols. And it made me wonder – I’ve implemented toy versions of traceroute, TCP and DNS. What about TLS? Could I implement a toy version of that to learn more about how it works? I asked on Twitter if...

Mar 2022

Celebrate tiny learning milestones

Hello! Today I want to talk about – how do you know you’re getting better at programming? One obvious approach is: make goals periodically check if you achieved those goals if you did, celebrate I kind of hate goals Goals can be useful, but a lot of the time I actually find them stressful and not that helpful. For example, here are...

Mar 2022