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Monthly Meanderings: August 2026

2026-09-01T00:00:00Z

Another month, another edition of “What’s Chris been up to?”. Fun fact: I very nearly published this post with a “[intro]” placeholder here instead of this paragraph, despite proofreading it multiple times. “Yep, that’s where the intro will go, all good”. Now instead we have this weirdly meta introduction.

Website updates and other projects

A few website updates this month, and one of them neatly addresses the “other projects” bit too. First, I’ve added a new fitness page which has some stats and information about my cycling and running. I’ve also added some fitness-related widgets to support that page and these monthly summaries, and a new music one you can see a bit further down.

I’ve also added what I think is quite a fun new feature: a post feed builder that lets you build RSS feeds containing only posts that are semantically similar (or dissimilar) to other posts. So if you want to only hear about my fitness journey you can pin a few of those posts, or if you want to exclude posts that talk about LLMs you can exclude a few of those. It’s basically super-charged fuzzy tags, but it means I don’t have to actually tag things.

I blogged about building a family of single-user services which is where most of my coding energy went this month. Those projects were almost entirely authored by LLMs, and I’m not hating the process. The models have got a lot better at coding, and I enjoyed getting to focus on the bigger picture aspects rather than getting bogged down in details. Rest assured, all the writing on my website is still 100% me. I am the load-bearing seam, here.

Entertainment

Back in March I said ‘I can’t do “what I listened to last month” stats until next month’, and then for the next four months completely forgot about it. Well, not any more! Now I come equipped with some stats about my monthly music habits:

	Album	Artist	Unique tracks played	Total tracks played
1	Fallen	Evanescence	8	40
2	Love, Drugs & Misery	Eva Under Fire	12	32
3	NEON VOID	Sumo Cyco	6	23
4	The Strange Case of…	Halestorm	11	21
5	Coming in Hot	DIAMANTE	9	20
6	Everest	Halestorm	7	20
7	Glory Days	Little Mix	5	20
8	From Zero	Linkin Park	9	19
9	KPop Demon Hunters (Soundtrack from the Netflix Film)	KPop Demon Hunters Cast	7	19
10	No Need to Argue	The Cranberries	6	19

I suspect I won’t show this every month, as it’s probably going to be quite same-y. I, shockingly, tend to play music that I like more than that which I don’t. I’ll usually either put on my “favourites” playlist, or my “daily mix” playlist which biases higher-rated tracks over lower ones. So effectively this just becomes a noisy view over how highly I’ve rated the tracks in an album. Maybe I can control for that, but then I’m not sure what it’d actually be showing… “Here are all the albums I played this month that I don’t usually play because I don’t like them as much as the other albums I’m not showing any more”? It’s a bit wordy. Back to the drawing board with that idea, I think.

I was away for a few weeks this month, including a few days at a small LAN event. Being at a computer gaming event meant that we, naturally, played some board games. Apparently I hit an h-index of 23 from these plays. That’s 23 games I’ve played at least 23 times each. I’ve been at 22 since December last year: obviously the higher the number goes, the harder it is to reach. I also go on and off games (and the whole hobby at times), which doesn’t help on that front. Anyway, here’s ~~Wonderwall~~ the plays for this month:

6 plays
3 plays
3 plays
1 play
1 play

No films this month, but my World of Warcraft habit has picked back up with the launch of the new season. They’ve made Mistweaver Monk, my previous specialisation, a lot less fun to play, so I’m focusing on one of my many alts: a Restoration Shaman:

Level 90

Female Dwarf

Restoration Shaman

309 average item level

Hirameth-Terenas

Professions

Midnight Blacksmithing		41/100
Midnight Inscription		72/100
Midnight Fishing		35/300

Mythic+

Altar of Fangs	+10	23:10	329
Den of Nalorakk	+10	27:36	325
Kings' Rest	+12	28:57	370
Murder Row	+12	28:37	371
Ruby Life Pools	+11	24:28	340
Temple of Sethraliss	+10	30:57	321
The Blinding Vale	+10	24:38	327
Voidscar Arena	+10	22:37	329
Total M+ rating	2711

View on blizzard.com View on raider.io

I don’t quite like it as much as Mistweaver in season 1, but it’s a lot nicer than Mistweaver in season 2. You can actually make health bars move when you press your healing buttons, rather than ignoring half of them because they’re not worth using.

Fitness

My running kick is still going. I’ve “officially” finished the couch-to-5k programme I was doing, and I actually hit 5k on the last day of the programme. I didn’t actually mean to do that: I was saving the 5k run for this week, but by the time I noticed I’d run “too far” it was close enough that I just kept going. I have an actual 5k race coming up this month, which is exciting. Once that’s over I’m planning to work my way up to 10k. I’ve added a few widgets to keep track of some stats:

activities

6h 5m

total time

103.6km

total distance

42.3km

longest distance

🏆️ New PB 1km 2:17 1:52
🏆️ New PB 2km 5:34 4:13
🏆️ New PB 5km 14:51 12:32
🏆️ New PB 10km 36:00 27:21
🏆️ New PB 20km 1:43:33 1:13:24
🏆️ New PB 30km no previous 1:54:25
🏆️ New PB 40km no previous 2:55:52

activities

6h 16m

total time

43.1km

total distance

5km

longest distance

🏆️ New PB 800m 5:56 6:02
🏆️ New PB 1km 7:35 7:36
🏆️ New PB 1 mile 12:28 12:16
🏆️ New PB 2km 15:35 15:16
🏆️ New PB 3km 24:32 23:05
🏆️ New PB 5km no previous 38:40

As well as the running, I did a couple of long (for me) cycle rides, clocking in at around 40 km. It’s a fun loop, but both times I did it I started flagging towards the end. The second time I made sure to eat and drink plenty along the way, and my legs still raised objections about halfway round. My next goal is 50 km which would let me get to the next town over and back but the route has a lot more elevation to go with its increased length, so it’s probably going to be quite a bit more taxing. I’m not sure when I’ll attempt that, as the weather is starting to turn. I was previously bemused when people mentioned “cycling seasons” and switching to indoor trainers. Then I wanted to go out when it was raining, and suddenly I understood. Running in the rain: surprisingly pleasant; cycling in the rain: no thank you.

Around the web

Hacker News In Uncompromised Detail

When I first read the title my gut reaction was “I know everything I need to know about Hacker News, right?”. The title is accurate though. There’s so much interesting stuff, presented really cleanly. It’s a good read.

A proposal for new Netflix content rating icons

Another dry sounding title, another fun article. It starts with a treatise on rating systems and ends with a lovely satirical list of rating ideas.

Find Git commits by commit message text

I like to think I’m relatively well versed in how to use Git. I can do an interactive rebase and everything! This tip from Ham was new to me, though, and is incredibly useful.

Novice Marathon Training Plan

Hal Higdon has a whole bunch of training plans. He literally wrote the book on marathon training. I’ll hopefully be following this plan next year, assuming I manage the 5k, 10k and half-marathon training! This would be the perfect plan for someone who’s run a half marathon a while ago, and is tempted to join me in my “marathon before I’m 40” goal…

Monthly Meanderings: March 2026

2026-04-01T00:00:00Z

Since last month’s update I’ve been unpleasantly reminded that I’m middle aged, through the medium of a dodgy knee. There’s nothing quite like not being able to stand up without groaning to underscore that you’re not young any more. The ongoing game of “will this seemingly mundane activity make my knee go funny again?” is a delight to play, too. I’m great at it.

Website updates

Two new blog posts this month: the longest way to represent a date is a short thought experiment on absurd date formats, and modern CSS is fun goes through some neat new CSS features I’ve used recently for this site.

I did some design tweaks this month: headers now have a blue background behind them¹, and a lot of components have been redesigned to have a consistent style. You can see that component in action in the new “now playing” widget I’ve added:

Chappell Roan — After Midnight The Rise and Fall of a Midwest Princess Scrobbled 2m ago

Instead of each component defining its own styles (which were mostly copied and pasted), there’s now a single class that handles the drop shadow, border, background colour, and the optional title. It also applies a consistent format to elements that are clickable: they use the blue accent colour for their borders, and have a glow effect shown on hover.

The now playing widget is part of a larger bit of work I did on importing some music stats. I’m pulling in the data from my Navidrome instance. A new music page shows my most listened albums and artists. Navidrome doesn’t store a complete play history, just the last play and the count, so I can’t do “what I listened to last month” stats until next month.

Other projects

Other than a minor bug-fix update to contempt, my Dockerfile templating/updating tool, I’ve not done much on my other open source projects. I’ve got a bit more work to do finish migrating all my repositories from GitHub to my private Forgejo instance. I’ve also been thinking about mirroring my public repositories to Codeberg so there’s a non-GitHub way to access them.

Entertainment

I apparently only watched a single film in March:

The Substance

2026-03-18

I really didn’t get on with this. It’s too long for what it is, and over-the-top in a way that just didn’t work for me.

Demi Moore and Margaret Qualley were great, but nothing else really was. The cinematography and sound design were too affected, the plot was pretty shallow and obvious, most of the body horror fell into the uncanny CGI valley for me.

It’s not completely without merit: there were around 40 minutes in the middle where I was really into it, but that’s not really enough given it’s closing in on a 2.5 hour runtime.

There’s something to be said for the message it’s presenting about women in Hollywood, too, but it was very heavy handed. Dennis Quaid’s character is even called Harvey; it’s not so much a subtle nod as a sledgehammer to the face.

Instead of films, I’ve been watching a bunch of TV. After devouring The Pitt last month, I struggled to find something to fill the hole it left. I settled on catching up on Chicago Fire and Chicago P.D.. They’re both mostly about getting things done without personal drama becoming the primary focus. They’re not quite as grounded as The Pitt, but at least they’ve not completely gone off the deep end like 9-1-1 where the first responders end up in space somehow?

I’ve also watched the first two episodes of SNL UK. I didn’t have very high expectations, and it gave me a pleasant surprise. Both episodes so far have some hilarious sketches, and are obviously written by British comics with the typical darker, more sardonic humour that separates us from the USA.

Last but not least, board games! I spent a weekend at a tabletop/LAN event with friends, so got to physically play some games for a change. I also kept up with some turn-based games on Board Game Arena, as usual.

6 plays
4 plays
4 plays
4 plays
3 plays
3 plays
3 plays
2 plays
2 plays
2 plays
2 plays
2 plays
1 play

Around the web

Warranty Void if Regenerated

Some really cool speculative fiction about a future where all software is written by LLMs, and the social effects that may have. Unfortunately the story itself is written with an LLM, and that becomes painfully obvious about a third of the way in. By that point I was already hooked, though.

My 2-step process for AI-free blogging

Speaking of LLM-generated text, this short piece by Manuel Moreale made me laugh. I’m by no means anti-LLM, but I really hate people publishing the output like it’s their own work. It breaks the social assumption that the writer put more effort in than the reader, and makes me wonder how much is hallucinated.

25 Years of Eggs

An interesting applied use of coding agents. I’m a sucker for personal statistics. I have no explicit desire to keep my receipts, or generate graphs of my egg consumption, but seeing the graphs makes me question that. The journey to get there is a great read, too.

I made a one-page notebook

The clever paper folding is interesting, but I really like some of the small touches on the page. There’s a nice little “in reply to” callout providing context at the top of the page, you can click to rotate the image further down, and there’s a details element containing a textual version of it. It has that great ‘small web’ vibe of someone who really cares about what they’re doing.

Workers who love ‘synergizing paradigms’ might be bad at their jobs

I haven’t read the full paper, but the summary given by the article is equal parts interesting and amusing. They developed a “Corporate Bullshit Receptivity Scale”, what more is there to say?

It’s meant to resemble painter’s tape, but I’m not sure quite how well it works. ↩︎

Modern CSS is fun

2026-03-17T00:00:00Z

I’ve been doing a bunch of CSS tweaking recently, and keep being surprised by how nice modern CSS is to work with. As someone grey-haired enough to remember writing HTML without CSS, it’s amazing to think how far along web technology has come¹. I wanted to demonstrate some of the handy bits and pieces I’ve used recently.

:has

The :has selector allows you to effectively query for child elements. While a span will match a <span> within an <a>, a:has(span) will match an <a> that contains a <span>. This really shines when combined with more complex selectors, for example:

input {
    border-radius: var(--border-radius);

    &:has(+ .results:not(:empty)) {
        border-bottom-left-radius: 0;
        border-bottom-right-radius: 0;
    }
}

This is part of the styling for my film search box. When the search box is presented initially it has fully rounded corners. But when it is followed by a non-empty results element, it removes the rounding on the bottom corners so that the border continues in a straight line down into the results. You can see it in action below; just enter a few characters (like “the”) to get some results:

You could achieve the same effect by having JavaScript add a class to the <input> element, but I’ll take a CSS solution over a JavaScript solution any day.

Nested rules

You probably spotted this in the example above. It’s what finally made me switch from SCSS to plain CSS. If you have a rule for .foo and a rule for .foo .bar you can just nest them. Not only does it save repeating yourself an awful lot, it keeps everything organised nicely. For example, the CSS for my film list embeds looks like this:

a.film-list {
    display: grid;
    grid-template-areas: "header images" "description images" "meta images";
    grid-template-columns: 1fr auto;
    grid-template-rows: auto 1fr auto;
    row-gap: var(--small-space);

    @media (width <= 800px) {
        grid-template-areas: "header" "description" "images" "meta";
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto auto;
    }

    & + & {
        margin-top: var(--medium-space);
    }

    h3 {
        font-size: var(--font-size-xxlarge);
    }

    .description {
        /* ... */
    }
}

Everything is wrapped up in a single bundle, including the @media rules for changing the layout on smaller screens, the lovely little & + & rule that adds some extra margin if there are two lists in a row, etc. The & syntax refers to the parent selector, so & + & in this case is the same as a.film-list + a.film-list: it’s very handy! The best part about this is that it’s the exact same syntax as SCSS, so converting is easy². The styled element looks like this:

Watched films ranked

Every film I’ve watched since I started logging, ranked.

Obviously super subjective, and subject to change often and arbitrarily.

264 films

Media range syntax

Once again, you might have spotted this in the previous snippet. I’m not deliberately teasing things, I promise! Back in the day, you did media queries like so:

@media (min-width: 1000px) and (max-width: 2000px) {
    /* some rules that work for screens at least 1000px wide and at most 2000px wide */
}

I always hated this syntax. I always got muddled up as to whether I wanted “min” or “max”, and whether they were inclusive or not. It’s easy to reason through, but it never came naturally. Fortunately you can now just use ranges:

@media (1000px <= width <= 2000px) {
    /* some rules that work for screens at least 1000px wide and at most 2000px wide */
}

I find this style so much easier to write and understand.

Anchor positioning

Trying to dynamically position one element next to another used to exclusively fall within the purview of JavaScript. Fortunately anchor positioning fixes all this. I use this in the film search field I showed above:

.film-search {
    input {
        anchor-name: --film-search-box;
    }
    .results {
        position: absolute;
        position-anchor: --film-search-box;
        position-area: bottom center;
        position-visibility: always;
        width: anchor-size();
    }
}

This does lots of fun things. The .results element is anchored to the input field (via the --film-search-box name), and it’s positioned on the bottom, directly under the anchor. The position-area rule describes a 3x3 grid, with the anchor at the center, so top left would put it diagonally adjacent to the anchor. Next, position-visibility keeps the .results element visible when the anchor isn’t; otherwise when you scroll the anchor off the screen the results would immediately vanish. Finally, the special anchor-size() function makes the .results element take up the same exact width as the anchor.

All-in-all, this puts the results exactly where I want them, without having to deal with any JavaScript at all. I can see how it’d also be amazingly useful trying to do tooltips or other forms of ‘floating’ content too. You can even leave the positioning up to the browser, giving it hints about which order to try, or what property to optimise for (e.g. you can say “anchor to the left or right, whichever has more horizontal space”).

attr() function

This one blew my mind a little. In some of the elements on the site, I’ve added a little label to the top. It looks something like this:

It’s meant to just be a visual flourish, not a semantic title or anything, so I initially just added a ::before selector to each element, customising the content to have the right value. I didn’t like the duplication, though. Now, instead, I do this:

&::before {
    content: attr(data-title);
}

Each component defines its title in a data attribute: <div class="raised-box" data-title="an example">, and the attr function plucks it out and puts it in the content rule. It’s worth noting that this is only widely supported for the content rule, you can’t yet use it for colours or dimensions or other things. It still feels a bit magical, though. Like you’re making a reusable, customisable component with just HTML and CSS.

layers

I’d come across layers a few times, but I never found a need for them. It seemed like something you’d only really need with complicated design systems, or something. Then I had a problem and layers were the perfect solution!

The headings on this site have a whole bunch of CSS attached to them. Currently they look a bit like blue painter’s tape with handwriting on them. This style is applied to all headers, and then the various places that don’t want it had to manually reset everything. I got fed up with that, so decided to add a plain-header class which would “disable” the extra styling:

h2,
h3,
h4,
h5,
h6 {
    /* common styles for all headers, regardless */
    font-family: "Chris Hand", sans-serif;
    font-size: var(--font-size-xxlarge);
    color: var(--text-highlight-colour);
    margin: var(--medium-space) 0;
    line-height: 1;

    &:not(.plain-header) {
        /* do fancy stuff if it _doesn't_ have the .plain-header class */
        transform: rotate(-0.15deg);
        padding: var(--smedium-space);
        font-weight: 800;
        filter: drop-shadow(3px 3px 5px rgb(0, 0, 0));

        a {
            background: none;
            text-decoration-skip-ink: auto;
        }
    }
}

This might seem a bit backwards but I want the default to be styled, as those are far more common. I added this change, sprinkled around some “plain-header” classes, tidied up a lot of duplicate CSS, and things mostly worked. Mostly. Some things stopped working. In a few places the headers had slight tweaks, and they stopped working entirely.

It turns out in moving the rules from a plain h2 selector to a h2:not(.plain-header), I’d made them more specific. Previously a selector like h2.special would have been more specific, so its properties would override those from the less specific h2 selector. My first reaction was to try and hack around it. Changing all the overrides to body h2.special would make them more specific again, but I didn’t want to have to remember to do that forever more.

Instead, I defined some custom layers, and put the header definitions in one:

@layer reset, links, headings

@layer headings {
    h2,
    h3 {
        /* etc */
    }
}

The first @layer rule defines some layers that will be handled in a specific order: first the “reset” layer, then the “links” layer, then the “headings” layer, and then anything not in a layer after that. Rules in one layer don’t have to worry about beating the specificity of rules in another layer, because they’re handled separately.

Note that I couldn’t just put the headings in a layer and call it a day: their rules have to come after the CSS reset, and after the normal link styles, as headers have a bit of extra styling for nested links. If the CSS reset weren’t in a layer, then the * { margin: 0; padding: 0; } type reset would apply over the rules from the headings layer.

Using layers is definitely a bit fiddly, and is not necessary for a lot of sites, but it’s a much cleaner alternative to ugly specificity hacking.

Things I’m looking forward to

There are a few things that aren’t (widely) available yet, that particularly interest me:

sibling-index() and sibling-count()

These new functions are available in WebKit and Blink based browsers, but not Firefox. They give you the index of the element within its siblings, or the count of siblings. For the film list component above, I currently have this abomination for the overlapping posters:

&:nth-child(1) {
    z-index: 5;
    left: 0;
}
&:nth-child(2) {
    z-index: 4;
    left: calc(133px * var(--overlap) * 1);
}
&:nth-child(3) {
    z-index: 3;
    left: calc(133px * var(--overlap) * 2);
}
&:nth-child(4) {
    z-index: 2;
    left: calc(133px * var(--overlap) * 3);
}
&:nth-child(5) {
    z-index: 1;
    left: calc(133px * var(--overlap) * 4);
}

These could be replaced with something like:

z-index: calc(1 + sibling-count() - sibling-index());
left: calc(133px * var(--overlap) * (sibling-index() - 1));

As an added bonus, it would scale to any number of posters. index being 1-based not 0-based is a bit unfortunate as it makes using it in calculations awkward (see 1 offset in both of those rules!), but it’s leagues better than writing 5 separate rules.

random()

Currently only available in Safari. There are a few places where I’d like to have slight random variations of the style. Things like elements that are rotated slightly for aesthetics; they look a bit silly if they’re all identically positioned. I also randomise the icons and positions of my rating stars to break up the visual monotony. Here are a few examples:

Currently I do the stars by hardcoding a bunch of classes and having the backend randomly apply one when it generates the markup for stars. Being able to do it in CSS would be great, though.

Mixins

This one’s so far off it’s not even listed on caniuse.com yet. Mixins are another handy feature of SCSS, that allow you to define reusable blocks of rules, then import them when needed:

@mixin fancy-background {
    background: /*...*/;
}

.some-element {
    @include fancy-background;
}

#other-element {
    @include fancy-background;
}

This would be particularly useful if you can’t easily control the markup to add classes to everything. For example, my footnotes are rendered by a markdown plugin, and don’t easily have a way to add extra classes to them. To style it the same as another element, I currently duplicate a bunch of rules between them both. Mixins would allow me to define those rules once, and then import them in both places.

Aside from JavaScript, which seems to just endlessly reinvent new frameworks and ways to make the most sprawling dependency tree possible. ↩︎
It also means that if your website’s syntax highlighting library doesn’t seem to understand nested rules, you can just pretend your perfectly valid CSS is actually SCSS and it’ll magically work. Grumble, grumble. ↩︎

An interesting Tailscale + Docker gotcha

2026-01-29T00:00:00Z

As I’ve written about before, I use Tailscale for a lot of things. I thought I had it set up in a reasonably secure manner, but I recently noticed a problem.

I use Tailscale’s ACLs to limit what each node can access, based on the tags I apply to it. So an app node can’t access anything via Tailscale, while an integration or server node can access things tagged with either app or integration. This is expressed pretty simply in the Tailscale ACL JSON:

{
	"tagOwners": {
		// Servers that can be SSH'd into
		"tag:server": [],
		// Applications that are exposed on tailscale but never connect out
		"tag:app": [],
		// Things which talk to other services over tailscale (connecting to apps etc)
		"tag:integration": [],
	},
	"grants": [
		{
			// Users can access everything
			"src": ["autogroup:member"],
			"dst": ["*"],
			"ip":  ["*"],
		},
		{
			// Servers and integrations can access integrations and apps
			"src": ["tag:server", "tag:integration"],
			"dst": ["tag:integration", "tag:app"],
			"ip":  ["*"],
		},
	],
}

Over the past week I’ve been setting up a private Forgejo instance behind Tailscale, complete with an actions runner that runs things using a docker-in-docker container. I didn’t want the runner knowing anything about Tailscale, so I had it configured to speak to Forgejo direct over HTTP (forgejo:3000) instead of using full Tailscale HTTPS URL that I use when accessing it (http://git.example-net.ts.net/)¹.

Everything was going fine, until I forgot to do that translation… and it worked. My Forgejo action runners could access anything on my tailnet. I run several things on Tailscale that just have authentication turned off, on the basis that only authorised devices can access them. Things like the admin interface for this website. I definitely didn’t intend for any workflow I run on my git server to have access to edit my website!

This wasn’t just limited to Forgejo, either. Any docker container I was running could access the tailnet. In hindsight it’s fairly obvious why: the host is running Tailscale, connected as a node tagged with my server tag. That creates a tailscale0 interface, and automagically sets up iptables rules to route Tailscale traffic over the interface. Docker also automagically sets up iptables rules to bridge traffic, and apparently these two sets of rules interact in such a way that traffic from Docker containers is allowed to route via the tailscale0 interface.

I say it’s fairly obvious in hindsight — there’s no reason why Docker would special case any particular host interface after all — but it still feels pretty surprising. Because both bits of software inject their own iptables rules, I never really had a good mental model for how they interact. The host Tailscale node was a completely separate building block to Docker. It would be a pain to use either of them if they didn’t do these rules, but it’s also one of the reasons I don’t really like “magical” things².

There are lots of ways to fix this, but none of them feel particularly great. You can configure both Tailscale and Docker to not automatically fiddle with iptables and handle the rules yourself, but I really hate dealing with iptables³. As a stopgap I did hold my nose and add some iptables rules to drop traffic to the tailscale0 interface if it originated from the IP ranges that Docker was configured to use:

iptables -I DOCKER-USER -s 192.168.0.0/16 -o tailscale0 -j DROP
iptables -I DOCKER-USER -s 172.17.0.0/12 -o tailscale0 -j DROP

The DOCKER-USER chain is a nice little escape hatch; it comes before the main auto-generated DOCKER chain, and Docker leaves the rules in it alone.

So I added these rules, and felt pretty good about myself, and then… everything started breaking in weird ways. After some debugging I realised the problem was DNS⁴. The server’s DNS resolver is 100.100.100.100, a special Tailscale address. This is so that it can resolve tailnet hostnames via MagicDNS (and so I don’t have to configure my custom DNS servers manually on each device; Tailscale does it for me). My new iptables rules inadvertently dropped all the DNS packets coming from docker containers. D’oh.

Obviously the solution here is to double down and add MORE iptables rules:

iptables -I DOCKER-USER -s 192.168.0.0/16 -d 100.100.100.100 -o tailscale0 -j ACCEPT
iptables -I DOCKER-USER -s 172.17.0.0/12 -d 100.100.100.100 -o tailscale0 -j ACCEPT

This got DNS working again, but it all feels a bit gross. Not least because to actually make these persist you need to use iptables-save, and then you also get all the rules that both Docker and Tailscale have inserted. I came across a script to filter out the Docker ones, but… yuck⁵.

I realised a cleaner idea might just be to lock down what server tagged nodes could access within Tailscale itself. That way I can avoid touching iptables at all. It’s handy to be able to curl services from the host when debugging, but it’s not really necessary. So I removed that access, and… stuff broke again. I’m using my Forgejo instance as a registry for some of the docker images I run, so the docker daemon needs to be able to reach it. I ended up making a new tag for infrastructure, which can be accessed from server devices. This does still allow all the docker containers to reach Forgejo, but I already have it set up with appropriate access controls and public/private repository splits. Forgejo is a service designed to run publicly, so this seems a reasonable trade-off for convenience. I used the tests feature of Tailscale’s ACL config to make sure I’d got the rules right:

{
	"tests": [
		{
			// Servers can only access infrastructure
			"src":   "tag:server",
			"proto": "tcp",
			"allow": [
				"tag:infrastructure:8080",
			],
			"deny": [
				"100.84.16.43:8080",
				"me@example.com:8080",
				"tag:server:8080",
				"tag:app:8080",
				"tag:integration:8080",
			],
		},
	],
}

The whole situation still feels a bit messy. If I ever get around to switching to nftables I might loop back and manually craft some rules for routing traffic, instead of leaving Tailscale and Docker to do their own thing.

I discovered later on that logging into the container registry at forgejo:3000 actually issued a redirect to https://git.example-net.ts.net/ so this was all basically for naught… ↩︎
I didn’t use Tailscale’s MagicDNS for a long time just because the word “magic” put me off. Only when I eventually got around to learning how it worked, and seeing that it wasn’t really that magical under the hood, did I change my mind. ↩︎
nftables seems far better in lots of ways, but I can’t really be bothered migrating. Maybe next time I reimage the server for whatever reason… ↩︎
It’s always DNS… ↩︎
Again, nftables would almost certainly help here. It actually has (gasp) configuration files. But again, I really didn’t want to spend the time migrating. ↩︎

Further Adventures in Music Organisation

2025-09-21T00:00:00Z

I wrote before about how I’d dropped Spotify in favour of locally stored music, but things have advanced a bit since. I had a few issues: Tauon would occasionally manage to lose its database and along with it all my carefully constructed playlists and song ratings¹, and the experience on my phone was not very fun.

I had to manually sync the music by plugging my phone in to the computer, and sometimes it just refused to mount the right partition. I don’t think there’s really a good way to debug an Apple phone not behaving properly when connected to a Linux desktop. Then I started wanting more than one playlist synced², and trying to find a way to make that work just broke me.

I spent a while looking at different ways of hosting the music centrally. Plexamp gets lots of good reviews, and I’ve used Plex a fair bit. I set about spinning up a Plex server, and just could not get it working. The server ran fine, served the web interface, but would neither associate with my account nor run standalone. The docs were contradictory and there was very little useful logging. After a lot of frustration, I stumbled across mentions that Plex block running on Hetzner. I assume that’s the cause of my issues, although I have no way to know for sure. I use Hetzner for all my servers and other hosted services, but Plex have decided I can’t run the self-hosted software that I have a lifetime subscription for there. What the actual fuck?

I could have probably worked around the arbitrary restriction, but I didn’t want to throw more time down the drain. Instead, I set up Navidrome, an open source music server. It supports the Subsonic protocol, which means you can use a whole slew of different clients with it (or even write your own). It also means there’s a nice way to get data in and out of it programmatically, which I recall being a bit of a fight with Plex.

Syncing and organising

All my music lived on my desktop, but now I wanted it on my server. At first I just used rsync to copy everything up. I’d maintain a local “master” copy, and periodically shove the changes to the server³. That quickly got old, so I set up Syncthing to keep the two folders in sync. That worked… for a while.

Concurrently, I was looking at improving the organisation of my music. It was mostly organised by some Go programs I’d thrown together to automate the importing, with no real validation of metadata or anything else. Some albums got split up into multiple folders because the tracks had different artists (and didn’t have an album artist set); some artists ended up with multiple folders with slight spelling or case variations. It was upsetting.

I’d used MusicBrainz Picard before to fix some issues, but I didn’t really like the UI, especially when trying to do bulk actions. The main alternative is beets, which describes itself as “the music geek’s media organiser”, and is entirely command line. I was intrigued.

I started playing around with beets, and quickly noticed a problem. Every time I changed a metadata tag in a music file, Syncthing had to upload the entire file. I was frequently changing tags across the whole library as I got beets set up how I wanted, and Syncthing was handling it by uploading gigabytes of files for every minor change. I was already a bit unhappy with having the content duplicated in two places, so now I was using a command line organiser I figured I could just get rid of my local copy and move everything to the server.

I set up a Docker container for beets, and then wrote some incredibly hacky shell scripts so I could run beet locally on my desktop and it would SSH to the server over Tailscale and exec into the container, passing the arguments along. Then I did one final sync of the music library, got rid of Syncthing, double checked I had a backup and deleted all of my local music.

Bears, Beets, Battlestar Galactica

Beets is amazing. It has a vast array of plugins that can do almost anything you could want with a music library, and the command line workflow works really well for me. It’s very well documented, and all the individual parts are pleasingly simple and easy to understand.

Here’s what it looks like when importing some new music:

Beets importing an album

If it doesn’t get a perfect match then it shows the closest matches, and summarises what’s different about them (missing tracks, different names, etc), and lets you decide what to do. Aside from the metadata matching, it’s doing a lot of things under the hood that aren’t necessarily apparent. It:

Looks up the genre from Last.fm
Analyses all the tracks and writes ReplayGain metadata to them
Fetches album art
Checks all the files to make sure they’re actually playable
Scrubs any existing metadata tags

It also maintains its own database, and you can query against it. The query language is both simple and quite powerful, like the rest of beets. As an example:

$ beet ls artist:"Linkin Park" year:2025 length:2:00..2:30 
Linkin Park - From Zero - Casualty

Almost all the other commands also let you use the query syntax, which makes the whole tool really powerful. Want to delete all country tracks that you added last month? No problem. Redownload all the album art for a certain band? Easy. You can even do smart playlists using the filters.

Actually playing music

With all this organisation, I’ve not actually mentioned one tiny detail: how I actually play music now. Navidrome has a web UI, which is perfectly usable, but I don’t really want my web browser involved as it makes balancing sound levels tricky, and getting media keys working is a pain. Thankfully there are loads of Subsonic clients. I’ve tried several, but eventually settled on Feishin on the desktop. It’s very pretty:

Feishin’s ’now playing’ screen

What attracted me to it, though, was its built-in support for Navidrome’s smart playlists. These aren’t even properly exposed in Navidrome’s web UI yet, but Feishin has a visual editor that lets you create and edit them. I ended up with an identical system to the playlists I had in Tauon: a “blacklist” playlist which are tracks I never want to play, a “favourites” playlist, and then an “everything” playlist which is the entire catalogue minus the blacklist.

On iOS I’ve settled on Arpeggi. It’s not actually on the App Store yet, but available via TestFlight. It’s one of those really nicely polished apps that are obviously a labour of love, not just out to do the minimum possible to get your money. It can cache songs offline, and automatically download entire playlists, and supports all of the standard Subsonic features like rating, reporting plays back to the server, and so on.

One unexpected benefit of using a central server is that it handles reporting plays to Last.fm and ListenBrainz instead of the clients. I don’t think I’ve ever bothered to configure my mobile clients to do that before, and now it just works automagically. I’m relying on those services more for recommendations and discovery, as that’s something you lose out on when self-hosting.

Making bad decisions about bitrates

With all the moving, copying, and organising, I started thinking about how large the collection was. The songs were all in different formats, depending on when and where I’d picked them up, and I couldn’t tell the difference between them. I did a test and transcoded an MP3 file down to 128kbps, and still couldn’t tell the difference. So armed with that sample size of 1, I transcoded the entire library and saved so much space.

I don’t remember which track I did that first test with, but it must have been a very unlucky pick. I quickly started to notice the distortions caused by the low bitrate. It was particularly bad in any song with a lot of treble, and started to really annoy me. I started a painful process of reimporting things in their original format. Beets came in clutch again, both with the import process (if you import a duplicate album, it asks if you want to replace the original, and shows the format and bitrate of them for comparison), and keeping track of what was left to fix (beet ls bitrate:..128000).

Having started paying more attention to the sound quality, I think I’ve been nibbled on by the audiophile bug. I’ve been trying to get new music in FLAC format where possible. I’m pretty sure I can’t tell the difference between a decent bitrate MP3 and a FLAC, but maybe if I got a better DAC and some nice headphones…? Someone please hide my credit card!

As for the library taking up a lot of space, I now realise it’s a price worth paying. I might need to swap out the server to one with more storage at some point in the future, but it’s generally worth upgrading every few years with rented dedicated servers anyway, as you often get more for the same amount of money. Next upgrade I’ll just make sure there’s an appropriately-sized disk instead of focusing entirely on RAM and CPU.

Writing more code

Naturally, this whole process spawned several side projects. When browsing albums in Navidrome, I was a bit upset that the album art wasn’t all a consistent size. I thought about scripting something to crop them consistently, but then I had a better idea, and jewelcase was born. It takes the album art, crops it down to a consistent size, and then renders it inside a jewel case. It applies some slight effects, like adjusting the colours, rounding the corners, and tweaking the edges so it looks a bit more real. I don’t know why⁴, but every time I see the effect it gives me a little spark of joy.

Album art, before and after jewelcase is applied

The other project is BASS, a tool that uses the Subsonic API to grab information about my music catalogue, and then generates a “Daily Mix” playlist. It uses a system of weights to select tracks semi-randomly, biasing towards favourite tracks, those that haven’t been played much, and a few other criteria. This gives me a nice balance between having my favourites on repeat, and exploring the full library at random.

All the weights in BASS are customisable, so I can tweak it to my heart’s desire, and anyone else can also run it and configure it entirely differently to me if they want to. I can’t imagine I would’ve been able to do that if I were using Plex!

I was running a version from git as the stable release had fun dependency issues on Arch, so it’s possible this wouldn’t be an issue in normal use. I also started backing up the database, but it’s still annoying to have to restore it. ↩︎
A “favourites” playlist for me, and a more “family friendly” playlist for when I’m playing music out loud that has a bit less screaming/swearing/etc. ↩︎
One of the reasons for starting this was being annoyed by the periodic sync to my phone, obviously it makes perfect sense to introduce a new, different periodic sync. ↩︎
Nostalgia? A little bit of OCD? Both? ↩︎