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NixOS Mailer

Thu, 01 Feb 2024 00:00:00 +0000

There has been a lot of talk in recent years how running your own email server is too hard. But it’s quite healthy for the email ecosystem to not have everyone use Gmail and Outlook. In my experience it isn’t too hard, just takes some work.

Caddy plugins on NixOS

Mon, 12 Jun 2023 00:00:00 +0000

Caddy is a very handy HTTP server with lots of built-in features. But every once in a while you need something more. Fortunately Caddy has a plugin API. But Caddy being written in Go, the plugins need to be added at compile-time. On NixOS, there are no plugins added by default, and there are a couple of things to note when adding them.

Generic "must" helper for Go

Fri, 19 May 2023 00:00:00 +0000

Go error handling can be a bit verbose. There are a lot of places where errors are unlikely or where they are so critical that a panic is preferred. Because of this there are lots of Must* -helpers in various packages. E.g. regexp.MustCompile.

Docker Multiarch Builds

Fri, 28 Apr 2023 00:00:00 +0000

Like many other developers, I have to work with computers with different processor architectures. For me it’s amd64 (x86_64) on the laptop and arm64 (aarch64) on the server. For some it may be the other way around. Fortunately I mostly write Go, which makes cross-compilation quite easy. Docker adds some extra steps, but is very nice for deploying software.

Deploy Hugo to NixOS on Push to Gitea

Tue, 28 Mar 2023 00:00:00 +0000

There are several ways to automate blog publishing from git push. This one is mine. Mostly notes for future self. I use Gitea, Hugo, Caddy and NixOS.

WebAuthn & Base64 encoding

Thu, 16 Mar 2023 00:00:00 +0000

I recently ran into a problem that seems to be present in a wide range of WebAuthn tutorials, but I don’t know where it originated.

SSH PKI on top of Web PKI

Tue, 28 Feb 2023 00:00:00 +0000

Reading Future Internet PKI schemes need to be bootstrapped through web PKI I was reminded by all the problems I’ve had with SSH (Secure SHell) PKI (Public Key Infrastructure). SSH host verification is trust-on-first-use (TOFU). So SSH is protected from man-in-the-middle (MITM) attacks unless the first connection falls prey to the attack.

Molly Guard for Ansible

Fri, 11 Nov 2022 00:00:00 +0000

The Jargon File defines Molly Guard as:

A shield to prevent tripping of some Big Red Switch by clumsy or ignorant hands. Originally used of the plexiglass covers improvised for the BRS on an IBM 4341 after a programmer’s toddler daughter (named Molly) frobbed it twice in one day. Later generalized to covers over stop/reset switches on disk drives and networking equipment. In hardware catalogues, you’ll see the much less interesting description “guarded button”.

Menu-driven Matrix Bot Interaction

Fri, 30 Sep 2022 00:00:00 +0000

I’m a huge fan of Matrix. A lot of the user value of modern chat platforms like Slack, Matrix and Discord (even IRC) comes from integrations to other services via bots. I had high hopes for MSC3006: Bot Interactions, but unfortunately it isn’t currently being pushed further. However, there exists an implementation of MSC3381: Polls.

Selectively running single role in Ansible

Wed, 10 Aug 2022 00:00:00 +0000

While I’ve been switching from Ansible to Nix lately, I still use Ansible and have written a fair share of Ansible YAML. A common trick I’ve used is to only run a specific Ansible role instead of the whole playbook. That can be achieved by using tags, but usually I haven’t tagged everything before I have the need.

Shorter wrapped error handling in Go

Mon, 30 May 2022 00:00:00 +0000

With Go 1.13 error wrapping was standardised with an interface in the standard library. When properly handling errors, you end up dealing with it a lot. The blog post suggests the following:

var e *QueryError
if errors.As(err, &e) {
	// err is a *QueryError, and e is set to the error's value
}

Generic pointer of value with Go

Wed, 18 May 2022 00:00:00 +0000

I’ve been writing a decent amount of Go during the past 8 years. While I like many things about Go, some of the design choices result in repetitive or longer than necessary code.

GlitchTip on arm64

Mon, 16 May 2022 00:00:00 +0000

Why does everything have to be so hard on arm64? Well, maybe not directly hard, but a lot more work. And the reason is simple, we live almost in a amd64 monoculture. Mobile phones are changing that, as is Apple M1, but also arm64 servers.

Roborock S6 Pure Troubleshooting

Fri, 15 Apr 2022 00:00:00 +0000

We have a Roborock S6 Pure robotic vacuum cleaner. It’s very nice having a device that more or less cleans the floors by itself. When it works. Ours stopped working a week ago, after working well for months.

Matrix Bot for the reMarkable eInk Tablet

Tue, 12 Apr 2022 00:00:00 +0000

I own a reMarkable 2 (referral link) eInk tablet. It’s pretty nice (except lately the manufacturer has tacked on a subscription service). And it can send documents as PDFs via email. But unlike the Kindle, you cannot send documents to the tablet via email. Well, there exists a third party service.

I saw someone post on reddit that they wrote a Telegram bot that can be used to upload documents to their reMarkable. That sounded interesting, but I’m partial to Matrix.

coturn for Ubuntu Jammy (22.04 LTS)

Mon, 11 Apr 2022 00:00:00 +0000

Today I had to install coturn on Ubuntu 22.04 (Jammy Jellyfish). It doesn’t have package available because of a bug. But there’s a solution on the bugtracker, so I decided to build my own package. It has been a while since I last did it, so here are the steps for reference:

Blog Comments with Matrix Using Cactus Comments

Fri, 01 Apr 2022 00:00:00 +0000

I’m not sure if comments improve blogs, but I’m willing to try. But my blog is a static site and I don’t like the idea of forcing Disqus on readers of my blog. Luckily there exists a project built on matrix for adding comments to your site.

Login Using Already Existing Matrix Account

Thu, 31 Mar 2022 00:00:00 +0000

I have a deep interest in both matrix and different authentication schemes. When I saw the HN discussion about “Sign in with Matrix”, I thought I could probably come up with something better.

Guide for Free Matrix Home Server

Wed, 30 Mar 2022 00:00:00 +0000

Having been on the Internet for decades, I’ve seen the growth of walled gardens and the associated problems. I hate it. Especially the messaging walled gardens.

RFC7807 - Problem Details for HTTP APIs

Thu, 24 Mar 2022 00:00:00 +0000

At some point when implementing HTTP APIs, just logging “error” and returning an empty response doesn’t cut it anymore. Good practise with REST APIs suggests returning a suitable HTTP status code, i.e. something other than 200 OK.

JWT Debugging

Wed, 23 Mar 2022 00:00:00 +0000

I need to remember to not stop at the following:

NixOS on Oracle Cloud

Thu, 17 Mar 2022 00:00:00 +0000

Oracle Cloud offers nice free virtual machines, but there was no installation image for NixOS. Luckily NixOS-infect worked really great.

Free clouds

Tue, 15 Mar 2022 00:00:00 +0000

Comparison of free cloud offerings (2023/08):

Unprofessional Support in MacHuolto, start of a blog

Sat, 15 Sep 2007 00:00:00 +0000

First, some background. I have an iBook G4 12" that I bought in August 2005, so that I would have a handy laptop during my studies. I also bought AppleCare, because I thought it would be better to pay 300€ extra to be sure that the laptop would serve me at least three years, instead of the one year default warranty. Of that decision, I’m glad.