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    <title>Chameth.com - posts like sense-api, tailscale-docker-gotcha, understanding-docker-volume-mounts, why-you-should-be-using-https but not migrating-from-github-to-forgejo</title>
    <subtitle>Personal homepage of Chris Smith</subtitle>
    <link href="https://chameth.com/feeds/posts/like/sense-api,tailscale-docker-gotcha,understanding-docker-volume-mounts,why-you-should-be-using-https/unlike/migrating-from-github-to-forgejo/" rel="self"/>
    <link href="https://chameth.com/"/>
    <icon>https://chameth.com/favicon.png</icon>
    <updated>2026-04-09T00:00:00Z</updated>
    <id>https://chameth.com/</id>
    <author>
        <name>Chris Smith</name>
    </author>
    <entry>
        <title>The Case of the Unchanging Config</title>
        <link href="https://chameth.com/the-case-of-the-unchanging-config/"/>
        <updated>2026-04-09T00:00:00Z</updated>
        <id>https://chameth.com/the-case-of-the-unchanging-config/</id>
        <content xml:lang="en" type="html">&lt;p&gt;Last week I was attempting to make it so I could share pictures on IRC directly from my client. This sounds simple, but it involves a bouncer&lt;sup id=&#34;fnref:1&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:1&#34; role=&#34;doc-noteref&#34;&gt;1&lt;/a&gt;&lt;/sup&gt; that proxies the request to a standalone image hosting service that I had to modify to be compatible. At one point my testing loop was:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;Make a change to the hosting service&lt;/li&gt;
&lt;li&gt;Commit it&lt;/li&gt;
&lt;li&gt;Tag a new release&lt;/li&gt;
&lt;li&gt;Wait for it to build&lt;/li&gt;
&lt;li&gt;Update the version I’m running on my server&lt;/li&gt;
&lt;li&gt;Reconfigure the bouncer to pass the new parameter or change the URL or whatever&lt;/li&gt;
&lt;li&gt;Try uploading a photo from my phone&lt;/li&gt;
&lt;li&gt;Realise I’ve overlooked something and go back to step one&lt;/li&gt;
&lt;/ol&gt;
&lt;p&gt;I &lt;em&gt;could&lt;/em&gt; have set up a local copy of everything and tested it sensibly. I &lt;em&gt;should&lt;/em&gt; have set up a local copy of everything and tested it sensibly. But it seemed like such a trivial change, and setting up the whole environment seemed like such a pain. After the third or so iteration of failure I was pretty annoyed with myself, computers, and basically everything.&lt;/p&gt;
&lt;p&gt;My biggest annoyance was that my bouncer would not pick up the new URL from the config when I changed it. It’s meant to reload the config when it receives a &lt;code&gt;SIGHUP&lt;/code&gt;, and it claimed to in the logs, but I could clearly see it was still hitting the old URL. Restarting the bouncer to update the config is a pain, as it disconnects me from all the IRC networks, and has to reconnect to them all, reauthenticate, etc. It also mildly spams everyone who shares a channel with me&lt;sup id=&#34;fnref:2&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:2&#34; role=&#34;doc-noteref&#34;&gt;2&lt;/a&gt;&lt;/sup&gt;.&lt;/p&gt;
&lt;p&gt;When I finally got everything working I had a look at the bouncer source, and thought I’d spotted the issue. I raised a bug report, ending in this remark:&lt;/p&gt;
&lt;blockquote&gt;
&lt;p&gt;It looks like the config is reloaded properly, but the handler for uploads is created once at startup and has its own copy of the uploader, so effectively snapshots the config to whatever it is at startup:&lt;/p&gt;
&lt;/blockquote&gt;
&lt;pre class=&#34;chroma-chroma&#34;&gt;&lt;code&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-nx&#34;&gt;fileUploadHandler&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-o&#34;&gt;:=&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;http&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nf&#34;&gt;HandlerFunc&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;(&lt;/span&gt;&lt;span class=&#34;chroma-kd&#34;&gt;func&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;(&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;w&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;http&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;ResponseWriter&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;r&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-o&#34;&gt;*&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;http&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;Request&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;)&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;    &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;cfg&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-o&#34;&gt;:=&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;srv&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nf&#34;&gt;Config&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;()&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;    &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;h&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-o&#34;&gt;:=&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;fileupload&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;Handler&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;        &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;Uploader&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;    &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;cfg&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;FileUploader&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;        &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;DB&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;          &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;db&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;        &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;Auth&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;        &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;cfg&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;Auth&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;        &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;HTTPOrigins&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;cfg&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;HTTPOrigins&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;    &lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;}&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-w&#34;&gt;    &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;h&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;.&lt;/span&gt;&lt;span class=&#34;chroma-nf&#34;&gt;ServeHTTP&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;(&lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;w&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt; &lt;/span&gt;&lt;span class=&#34;chroma-nx&#34;&gt;r&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;)&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-p&#34;&gt;})&lt;/span&gt;&lt;span class=&#34;chroma-w&#34;&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;I’m not quite sure what I thought I saw there, but that’s not right. I want to call it a hallucination, but that feels like a very overloaded word these days. I guess I was just seeing what I wanted to see, and that was a good excuse to stop investigating. Still, even if I misidentified the cause, the bug was still present, right? … Right?&lt;/p&gt;
&lt;h3 id=&#34;the-science-of-deduction&#34;&gt;The Science of Deduction&lt;/h3&gt;
&lt;p&gt;When the developer got back and said he couldn’t reproduce my issue, I went back to my install and immediately reproduced it. With a calmer head, I figured it was probably something with my particular set up. First thing to check: am I actually running the version I think I am?&lt;/p&gt;
&lt;p&gt;Unfortunately the bouncer doesn’t actually seem to expose the version anywhere that I can see. It’s not in the logs, it doesn’t have a &lt;code&gt;-version&lt;/code&gt; flag, and none of the IRC-based status commands seem to include it. But I know it’s a Go app, and I know Go embeds the version information. &lt;code&gt;go version -m &amp;lt;binary&amp;gt;&lt;/code&gt; will dump it all out, but the binary is inside a Docker image, and the Docker image is one of my &lt;a href=&#34;https://chameth.com/artisanal-docker-images/&#34;&gt;nice, minimal, artisanal ones&lt;/a&gt; so doesn’t ship a &lt;code&gt;go&lt;/code&gt; binary. No problem, &lt;code&gt;docker compose cp bouncer:/bnc ./bnc&lt;/code&gt; yoinks the binary out of the container, and then dumping the version shows that, yes, I am running the version I thought I was. Hmm.&lt;/p&gt;
&lt;p&gt;The next tool I reached for in &lt;a href=&#34;https://chameth.com/debugging-beyond-the-debugger/&#34;&gt;my toolbox&lt;/a&gt; was &lt;code&gt;strace&lt;/code&gt;. Maybe it’s not actually reading the file for some reason? I immediately executed &lt;code&gt;strace -p &amp;lt;pid&amp;gt; -e trace=openat,open,read,pread64 -f&lt;/code&gt; without having to look any part of that up. Yep. Definitely. Then I edited the config, &lt;code&gt;HUP&lt;/code&gt;’d the bouncer, and saw that it was… reading the config file. As it’s meant to. By default &lt;code&gt;strace&lt;/code&gt; truncates strings to 32 bytes, so I couldn’t actually see the line I’d changed. Some more definitely-not-RTFMing later, and rerunning it with an extra &lt;code&gt;-s 65536&lt;/code&gt; let me see the full config. Surprise! The config hadn’t changed!&lt;/p&gt;
&lt;p&gt;To confirm my findings, I used &lt;code&gt;docker compose cp&lt;/code&gt; again, this time yoinking the config file from inside the container. The inside config file was definitely different to the outside config file. What? My hypothesis at this point was “something something Docker nonsense”. I mount the config as read-only, and was wondering if that meant that Docker was doing something &lt;em&gt;weird&lt;/em&gt; instead of just bind mounting it. A quick trip to &lt;code&gt;/proc/&amp;lt;pid&amp;gt;/mounts&lt;/code&gt; showed that it was, in fact, not doing anything weird, and was just bind mounting it.&lt;/p&gt;
&lt;p&gt;If the file is bind mounted, then surely it’s the same file? I ran &lt;code&gt;stat&lt;/code&gt; on the file on the host, noted the inode number, then pondered how to actually run &lt;code&gt;stat&lt;/code&gt; on the file inside the container, given the aforementioned awkwardly minimal image. The solution was easy: access it via &lt;code&gt;/proc/&amp;lt;pid&amp;gt;/root/&lt;/code&gt;. I could’ve saved myself a bunch of &lt;code&gt;docker compose cp&lt;/code&gt; if I’d thought about that earlier. Oh well. The inode of that file was different. What?&lt;/p&gt;
&lt;p&gt;The answer was DNS. It’s always DNS. Oh, sorry, force of habit. I meant the answer was &lt;em&gt;vim&lt;/em&gt;. I was editing the config in vim, and when it saves files, by default, it writes the new content to a temporary file and does an atomic rename. That’s normally a good thing: it prevents corruption if the write fails midway through&lt;sup id=&#34;fnref:3&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:3&#34; role=&#34;doc-noteref&#34;&gt;3&lt;/a&gt;&lt;/sup&gt;. In this case, though, that means the new file has a new inode. Bind mounting a file binds to the inode, so the container just keeps clutching onto the original config from when it was started, blissfully unaware that the party has relocated down the street.&lt;/p&gt;
&lt;p&gt;This problem is likely to happen whenever you bind mount a file into a container. When I mentioned this to a friend, he immediately responded “oh yeah, never do that”, and went on to describe the horrible hacks he’s had to add to Ansible to sidestep the issue. The nicer solution is to just bind mount an entire directory if you can, as then it doesn’t matter what happens to the files within it. I really like having the config files sat alongside the Docker compose files, though; having to create a directory just to work around some bind mount weirdness upsets me.&lt;/p&gt;
&lt;p&gt;Now I knew what the problem was, I found there was an issue &lt;a href=&#34;https://github.com/moby/moby/issues/6011&#34;&gt;raised against Docker&lt;/a&gt; twelve years ago&lt;sup id=&#34;fnref:4&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:4&#34; role=&#34;doc-noteref&#34;&gt;4&lt;/a&gt;&lt;/sup&gt;. The first response was “that’s expected”, and I fully agree with the author: “respectfully, that might be expected by you, but it was not expected by me”!&lt;sup id=&#34;fnref:5&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:5&#34; role=&#34;doc-noteref&#34;&gt;5&lt;/a&gt;&lt;/sup&gt; As a result of the issue they &lt;a href=&#34;https://github.com/moby/moby/pull/6854/changes&#34;&gt;added a nice note to the docs&lt;/a&gt;:&lt;/p&gt;
&lt;blockquote&gt;
&lt;p&gt;&lt;strong&gt;Note:&lt;/strong&gt;
Many tools used to edit files including &lt;code&gt;vi&lt;/code&gt; and &lt;code&gt;sed --in-place&lt;/code&gt; may result
in an inode change. Since Docker v1.1.0, this will produce an error such as
“&lt;em&gt;sed: cannot rename ./sedKdJ9Dy: Device or resource busy&lt;/em&gt;”. In the case where
you want to edit the mounted file, it is often easiest to instead mount the
parent directory.&lt;/p&gt;
&lt;/blockquote&gt;
&lt;p&gt;But in the intervening twelve years, both the note and the functionality described have gone missing. Ho-hum.&lt;/p&gt;
&lt;p&gt;I found it interesting how I’ve only just hit this problem, given how long I’ve used Docker. But I realised that almost everything I run I’m happy to just restart. Cattle, not pets, and so on. My IRC bouncer is one of the few exceptions to that. The only other thing I regularly hot reloaded was &lt;a href=&#34;https://github.com/csmith/centauri&#34;&gt;Centauri&lt;/a&gt;, my reverse proxy, but that had a whole config directory mounted because it was shared between containers, so nicely sidestepped the foot-gun.&lt;/p&gt;
&lt;p&gt;So lesson learnt: check for weird bind mount issues before raising issues about config hot reloading. It’ll join the esteemed company of “maybe the drive is full and causing completely unrelated problems?”, “perhaps everything is dog slow because the kernel ran out of entropy?”, and “did systemd sneakily take over that functionality while you weren’t looking?” in the troubleshooting checklist.&lt;/p&gt;
&lt;div class=&#34;footnotes&#34; role=&#34;doc-endnotes&#34;&gt;
&lt;hr/&gt;
&lt;ol&gt;
&lt;li id=&#34;fn:1&#34;&gt;
&lt;p&gt;An IRC bouncer is basically an always-on proxy. It connects to the IRC networks for you, then your clients connect to your bouncer. The bouncer can then send incoming messages to all your different clients, cache them when you’re offline and replay them later, and lots of other nice things people take for granted in their chat apps these days. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:1&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:2&#34;&gt;
&lt;p&gt;Join/part/quit spam is part of IRC, and clients have ways of handling it, but I still &lt;em&gt;feel&lt;/em&gt; bad about doing it excessively. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:2&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:3&#34;&gt;
&lt;p&gt;You can disable this in vim by setting &lt;code&gt;backupcopy=yes&lt;/code&gt;. Good luck redoing all the debugging if you ever accidentally remove that from your &lt;code&gt;vimrc&lt;/code&gt;, though! &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:3&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:4&#34;&gt;
&lt;p&gt;Which is weird, because Docker can’t possibly be that old. That would make me much older than I’m prepared to accept. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:4&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:5&#34;&gt;
&lt;p&gt;If you read the thread they didn’t actually mean to sound so dismissive, but it’s still pretty funny. “Yes, it’s expected that the foot-gun causes your foot to hurt. Duh. What did you expect?” &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:5&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;/ol&gt;
&lt;/div&gt;
</content>
    </entry>
    <entry>
        <title>An interesting Tailscale + Docker gotcha</title>
        <link href="https://chameth.com/tailscale-docker-gotcha/"/>
        <updated>2026-01-29T00:00:00Z</updated>
        <id>https://chameth.com/tailscale-docker-gotcha/</id>
        <content xml:lang="en" type="html">&lt;p&gt;As I’ve &lt;a href=&#34;https://chameth.com/how-i-use-tailscale/&#34;&gt;written&lt;/a&gt; &lt;a href=&#34;https://chameth.com/avoiding-the-consequences-of-dumb-laws-with-tailscale/&#34;&gt;about&lt;/a&gt; &lt;a href=&#34;https://chameth.com/exposing-game-servers-over-tailscale/&#34;&gt;before&lt;/a&gt;, I use &lt;a href=&#34;https://tailscale.com/&#34;&gt;Tailscale&lt;/a&gt; for a lot of things. I thought I had it set up in a reasonably secure manner, but I recently noticed a problem.&lt;/p&gt;
&lt;p&gt;I use Tailscale’s ACLs to limit what each node can access, based on the tags I apply to it. So an &lt;code&gt;app&lt;/code&gt; node can’t access anything via Tailscale, while an &lt;code&gt;integration&lt;/code&gt; or &lt;code&gt;server&lt;/code&gt; node can access things tagged with either &lt;code&gt;app&lt;/code&gt; or &lt;code&gt;integration&lt;/code&gt;. This is expressed pretty simply in the Tailscale ACL JSON:&lt;/p&gt;
&lt;pre class=&#34;chroma-chroma&#34;&gt;&lt;code&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;	&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;tagOwners&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-c1&#34;&gt;// Servers that can be SSH&amp;#39;d into
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;tag:server&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-c1&#34;&gt;// Applications that are exposed on tailscale but never connect out
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;tag:app&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-c1&#34;&gt;// Things which talk to other services over tailscale (connecting to apps etc)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;tag:integration&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;	&lt;span class=&#34;chroma-p&#34;&gt;},&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;	&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;grants&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-c1&#34;&gt;// Users can access everything
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;src&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;autogroup:member&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;dst&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;*&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;ip&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;  &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;*&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;},&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-c1&#34;&gt;// Servers and integrations can access integrations and apps
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;src&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:server&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt; &lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:integration&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;dst&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:integration&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt; &lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:app&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;ip&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;  &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;*&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;},&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;	&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-p&#34;&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;Over the past week I’ve been setting up a private &lt;a href=&#34;https://forgejo.org/&#34;&gt;Forgejo&lt;/a&gt; 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 (&lt;code&gt;forgejo:3000&lt;/code&gt;) instead of using full Tailscale HTTPS URL that I use when accessing it (&lt;code&gt;http://git.example-net.ts.net/&lt;/code&gt;)&lt;sup id=&#34;fnref:1&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:1&#34; role=&#34;doc-noteref&#34;&gt;1&lt;/a&gt;&lt;/sup&gt;.&lt;/p&gt;
&lt;p&gt;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!&lt;/p&gt;
&lt;p&gt;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 &lt;code&gt;server&lt;/code&gt; tag. That creates a &lt;code&gt;tailscale0&lt;/code&gt; 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 &lt;code&gt;tailscale0&lt;/code&gt; interface.&lt;/p&gt;
&lt;p&gt;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” things&lt;sup id=&#34;fnref:2&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:2&#34; role=&#34;doc-noteref&#34;&gt;2&lt;/a&gt;&lt;/sup&gt;.&lt;/p&gt;
&lt;p&gt;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 iptables&lt;sup id=&#34;fnref:3&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:3&#34; role=&#34;doc-noteref&#34;&gt;3&lt;/a&gt;&lt;/sup&gt;. As a stopgap I did hold my nose and add some iptables rules to drop traffic to the &lt;code&gt;tailscale0&lt;/code&gt; interface if it originated from the IP ranges that Docker was configured to use:&lt;/p&gt;
&lt;pre class=&#34;chroma-chroma&#34;&gt;&lt;code&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;iptables -I DOCKER-USER -s 192.168.0.0/16 -o tailscale0 -j DROP
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;iptables -I DOCKER-USER -s 172.17.0.0/12 -o tailscale0 -j DROP
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;The &lt;code&gt;DOCKER-USER&lt;/code&gt; chain is a nice little escape hatch; it comes before the main auto-generated &lt;code&gt;DOCKER&lt;/code&gt; chain, and Docker leaves the rules in it alone.&lt;/p&gt;
&lt;p&gt;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 DNS&lt;sup id=&#34;fnref:4&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:4&#34; role=&#34;doc-noteref&#34;&gt;4&lt;/a&gt;&lt;/sup&gt;. The server’s DNS resolver is &lt;code&gt;100.100.100.100&lt;/code&gt;, a special Tailscale address. This is so that it can resolve tailnet hostnames via &lt;a href=&#34;https://tailscale.com/kb/1081/magicdns&#34;&gt;MagicDNS&lt;/a&gt; (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.&lt;/p&gt;
&lt;p&gt;Obviously the solution here is to double down and add MORE iptables rules:&lt;/p&gt;
&lt;pre class=&#34;chroma-chroma&#34;&gt;&lt;code&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;iptables -I DOCKER-USER -s 192.168.0.0/16 -d 100.100.100.100 -o tailscale0 -j ACCEPT
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;iptables -I DOCKER-USER -s 172.17.0.0/12 -d 100.100.100.100 -o tailscale0 -j ACCEPT
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;This got DNS working again, but it all feels a bit gross. Not least because to actually make these persist you need to use &lt;code&gt;iptables-save&lt;/code&gt;, and then you also get all the rules that both Docker and Tailscale have inserted. I came across &lt;a href=&#34;https://github.com/giangi/iptables-docker-filter&#34;&gt;a script&lt;/a&gt; to filter out the Docker ones, but… yuck&lt;sup id=&#34;fnref:5&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:5&#34; role=&#34;doc-noteref&#34;&gt;5&lt;/a&gt;&lt;/sup&gt;.&lt;/p&gt;
&lt;p&gt;I realised a cleaner idea might just be to lock down what &lt;code&gt;server&lt;/code&gt; tagged nodes could access within Tailscale itself. That way I can avoid touching iptables at all. It’s handy to be able to &lt;code&gt;curl&lt;/code&gt; 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 &lt;code&gt;infrastructure&lt;/code&gt;, which can be accessed from &lt;code&gt;server&lt;/code&gt; 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 &lt;code&gt;tests&lt;/code&gt; feature of Tailscale’s ACL config to make sure I’d got the rules right:&lt;/p&gt;
&lt;pre class=&#34;chroma-chroma&#34;&gt;&lt;code&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;	&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;tests&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-c1&#34;&gt;// Servers can only access infrastructure
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;src&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;   &lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:server&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;proto&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tcp&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;allow&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;				&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:infrastructure:8080&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;deny&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;				&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;100.84.16.43:8080&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;				&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;me@example.com:8080&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;				&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:server:8080&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;				&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:app:8080&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;				&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;tag:integration:8080&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;},&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;	&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;&lt;span class=&#34;chroma-p&#34;&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;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.&lt;/p&gt;
&lt;div class=&#34;footnotes&#34; role=&#34;doc-endnotes&#34;&gt;
&lt;hr/&gt;
&lt;ol&gt;
&lt;li id=&#34;fn:1&#34;&gt;
&lt;p&gt;I discovered later on that logging into the container registry at &lt;code&gt;forgejo:3000&lt;/code&gt; actually issued a redirect to &lt;code&gt;https://git.example-net.ts.net/&lt;/code&gt; so this was all basically for naught… &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:1&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:2&#34;&gt;
&lt;p&gt;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. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:2&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:3&#34;&gt;
&lt;p&gt;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… &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:3&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:4&#34;&gt;
&lt;p&gt;It’s always DNS… &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:4&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:5&#34;&gt;
&lt;p&gt;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. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:5&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;/ol&gt;
&lt;/div&gt;
</content>
    </entry>
    <entry>
        <title>Exposing game servers over Tailscale</title>
        <link href="https://chameth.com/exposing-game-servers-over-tailscale/"/>
        <updated>2025-12-07T00:00:00Z</updated>
        <id>https://chameth.com/exposing-game-servers-over-tailscale/</id>
        <content xml:lang="en" type="html">&lt;p&gt;I’ve recently been playing a lot of &lt;a href=&#34;https://factorio.com/&#34;&gt;Factorio&lt;/a&gt; with a friend. I’ve been
hosting, but my desktop computer is behind far too many layers of NAT, and I can’t be bothered
dealing with setting up port forwards. Up until today we made do with Steam’s networking support,
which in our case ended up relaying the connection via one of their servers. This is amazing as
a free, no-hassle service, but the performance was so-so. We’d get random lag spikes, or the
initial map download would crawl along at about 1/100th of the speed we should be able to get.
We’re both fans of &lt;a href=&#34;https://tailscale.com/&#34;&gt;Tailscale&lt;/a&gt; though, so maybe there’s an easy solution
there?&lt;/p&gt;
&lt;p&gt;Tailscale even have an article on &lt;a href=&#34;https://tailscale.com/blog/factorio-multiplayer-video&#34;&gt;sharing a Factorio server&lt;/a&gt;
but it’s a ten minute long video&lt;sup id=&#34;fnref:1&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:1&#34; role=&#34;doc-noteref&#34;&gt;1&lt;/a&gt;&lt;/sup&gt;, and focused on setting up an actual dedicated server in Docker
rather than just clicking the convenient “Host” button in the game client. What we did instead was:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;I shared my desktop’s Tailscale node with my friend, by creating a sharing link in the &lt;a href=&#34;https://login.tailscale.com/admin/machines&#34;&gt;Admin console&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;My friend accepted the link, and could then see my machine in their admin panel&lt;/li&gt;
&lt;li&gt;I used &lt;code&gt;tailscale lock&lt;/code&gt; to sign my friend’s desktop’s node key, as I have &lt;a href=&#34;https://tailscale.com/kb/1226/tailnet-lock&#34;&gt;tailnet lock&lt;/a&gt; enabled&lt;/li&gt;
&lt;li&gt;I added a grant to my tailnet’s ACL to permit access from my friend to the specific IP/port on my tailnet:&lt;/li&gt;
&lt;/ol&gt;
&lt;pre class=&#34;chroma-chroma&#34;&gt;&lt;code&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;src&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;friend@example.com&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;dst&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt; &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;100.0.0.42&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;,&lt;/span&gt; &lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;fd7a::42&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;			&lt;span class=&#34;chroma-nt&#34;&gt;&amp;#34;ip&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;:&lt;/span&gt;  &lt;span class=&#34;chroma-p&#34;&gt;[&lt;/span&gt;&lt;span class=&#34;chroma-s2&#34;&gt;&amp;#34;udp:34197&amp;#34;&lt;/span&gt;&lt;span class=&#34;chroma-p&#34;&gt;],&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span class=&#34;chroma-line&#34;&gt;&lt;span class=&#34;chroma-cl&#34;&gt;		&lt;span class=&#34;chroma-p&#34;&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;After this, my friend could connect to Factorio by entering the Tailscale IP address, or the Tailscale hostname (as they use &lt;a href=&#34;https://tailscale.com/kb/1081/magicdns&#34;&gt;MagicDNS&lt;/a&gt;).
Running &lt;code&gt;tailscale status&lt;/code&gt; shows that Tailscale managed to establish a direct connection despite the many layers of NAT involved,
and the performance improvements were significant and immediate.&lt;/p&gt;
&lt;p&gt;We did a bit of testing, and confirmed that no other services on my machine are accessible. And sharing a machine by default
only allows it to accept incoming connections, so I can’t get unwanted access to anything on my friend’s Tailnet, either.&lt;/p&gt;
&lt;p&gt;I’ve &lt;a href=&#34;https://chameth.com/how-i-use-tailscale/&#34;&gt;written before&lt;/a&gt; about all the different ways I use Tailscale; this is yet
another new way it’s solved a problem for me.&lt;/p&gt;
&lt;div class=&#34;footnotes&#34; role=&#34;doc-endnotes&#34;&gt;
&lt;hr/&gt;
&lt;ol&gt;
&lt;li id=&#34;fn:1&#34;&gt;
&lt;p&gt;I’m not a fan of video tutorials at the best of times, but especially not when I want to do something as quickly as possible so I can get back to &lt;del&gt;my addiction&lt;/del&gt; growing the factory. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:1&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;/ol&gt;
&lt;/div&gt;
</content>
    </entry>
    <entry>
        <title>Avoiding the Consequences of Dumb Laws with Tailscale</title>
        <link href="https://chameth.com/avoiding-the-consequences-of-dumb-laws-with-tailscale/"/>
        <updated>2025-09-30T00:00:00Z</updated>
        <id>https://chameth.com/avoiding-the-consequences-of-dumb-laws-with-tailscale/</id>
        <content xml:lang="en" type="html">&lt;p&gt;More and more sites are implementing privacy-invading age checks or just
completely blocking the UK thanks to the &lt;a href=&#34;https://www.legislation.gov.uk/ukpga/2023/50/contents&#34;&gt;Online Safety Act&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;Protecting kids from &lt;em&gt;some&lt;/em&gt; content online is certainly a noble goal, but
the asinine guidance from Ofcom, threats of absolutely disproportionate fines,
and the stupidly broad categories of content have resulted in companies just
giving up or going through a tick-box exercise that offers very little
protection but lots of inconvenience and a complete invasion of privacy.&lt;/p&gt;
&lt;p&gt;Instead of uploading my ID to some third party company, I’ve taken to proxying
my traffic through to a country that doesn’t have such stupid laws. Thankfully,
Tailscale makes this really easy. I’ve discussed &lt;a href=&#34;https://chameth.com/how-i-use-tailscale/&#34;&gt;how I use Tailscale&lt;/a&gt;
before, but not really covered &lt;em&gt;app connectors&lt;/em&gt;. I find Tailscale’s description
of these pretty confusing, but they basically amount to automatic, DNS-based
subnet routing configurations (or, to put it another way, a per-website exit
node). You can safely ignore all references to ‘SaaS apps’ in their docs.&lt;/p&gt;
&lt;p&gt;I create a custom app connector, and give it the domains to be included:&lt;/p&gt;
&lt;figure class=&#34;image full&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/avoiding-the-consequences-of-dumb-laws-with-tailscale/apps.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/avoiding-the-consequences-of-dumb-laws-with-tailscale/apps.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/avoiding-the-consequences-of-dumb-laws-with-tailscale/apps.png&#34; alt=&#34;Screenshot of the app section in the Tailscale admin console. It shows a table with two entries: &amp;#39;reddit&amp;#39; and &amp;#39;bluesky&amp;#39;. Each entry has a list of domain names like &amp;#39;*.reddit.com, *.reddit.it&amp;#39;.&#34; loading=&#34;lazy&#34; width=&#34;1151&#34; height=&#34;397&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;App configuration in the Tailscale admin console&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;Tailscale then magically resolves those domains, and has the ‘connector’
advertise routes for them. Any client that accepts routes will start sending
requests to the connector, which passes them onto the Internet at large. Any
other traffic is left alone, unlike when you use an exit node.&lt;/p&gt;
&lt;p&gt;The special bit here is how you can specify wildcard domains. Tailscale proxies
the DNS requests from clients (so it can inject responses for nodes on your
tailnet), which means it can dynamically update the routes as you resolve new
domains. I tried to set this up more manually, and quickly came unstuck: despite
using the same DNS servers, my server and my desktop would get different responses
for the same query as it varied by geography. Trying to get the full set of
IPs (and keeping them updated) would have been a nightmare. Tailscale expanding
the wildcards nicely sidesteps all of that.&lt;/p&gt;
&lt;p&gt;At first I was just proxying the traffic to one of my servers, but just today
I added a new connector for Imgur and found I was still blocked, just for
different reasons. They not only block my entire country but also a load
of known datacenter IP ranges. Hmph. I fixed this by hacking up a new side
project: &lt;a href=&#34;https://github.com/csmith/tsv&#34;&gt;tsv&lt;/a&gt;. It’s a simple Go app that accepts
traffic from the tailnet (advertising itself as both an app connector and an
exit node), and passes it on to another VPN.&lt;/p&gt;
&lt;p&gt;There are lots of other ways you could accomplish this, but this makes it so
all my devices can still access services without any additional configuration.
As long as Tailscale is installed, the Internet will still work as it’s meant
to, without all the nonsense. If I come across a site that doesn’t work, adding
it is trivial: I just make a new app connector in Tailscale.&lt;/p&gt;
&lt;p&gt;Obvious disclaimer: the laws in the UK are binding on the service providers,
not the end user. Doing this sort of thing in other countries might be illegal.
I don’t know; do your own research! Also all of this is a workaround
for something that should be fixed at a legislative level, but I’m not holding
my breath.&lt;/p&gt;
</content>
    </entry>
    <entry>
        <title>10 Weeks with an Apple Watch 10</title>
        <link href="https://chameth.com/10-weeks-with-an-apple-watch-10/"/>
        <updated>2025-09-09T00:00:00Z</updated>
        <id>https://chameth.com/10-weeks-with-an-apple-watch-10/</id>
        <content xml:lang="en" type="html">&lt;figure class=&#34;image right&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/10-weeks-with-an-apple-watch-10/watch.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/10-weeks-with-an-apple-watch-10/watch.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/10-weeks-with-an-apple-watch-10/watch.jpg&#34; alt=&#34;An Apple Watch 10 being worn, with a blue analogue clock on the display, and icons/data shown in the corners&#34; loading=&#34;lazy&#34; width=&#34;500&#34; height=&#34;644&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;My watch. Yes, I am available for wrist modelling opportunities.&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;Around ten weeks ago&lt;sup id=&#34;fnref:1&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:1&#34; role=&#34;doc-noteref&#34;&gt;1&lt;/a&gt;&lt;/sup&gt; I picked up an Apple Watch 10, and have been wearing
it almost constantly since. It’s not my first Apple Watch — I had a Series 5
for a bit back in 2020 — but it’s the first time I’ve actually stuck with it.
Ten weeks seems like an apt time to reflect on it.&lt;/p&gt;
&lt;p&gt;Firstly, why did I even bother? Well, for a couple of years I’d been wearing
a Xiaomi Smart Band 7, mainly to monitor my sleep stats and set alarms that
won’t wake up everyone else nearby. Its battery life was fantastic — with
notifications and other things turned off, I got about a month of use between
charges — but actually using it felt like trying to order food via the medium
of interpretive dance.&lt;/p&gt;
&lt;p&gt;My biggest gripe was the screen lock. If I didn’t have the screen locked then
I’d periodically trigger it during the night when I moved around
and it came in contact with my chest or leg. With the lock enabled you had to
deliberately swipe up from bottom to top to enable interaction, but it
didn’t work reliably. When I wanted to adjust an alarm, I’d be stood swiping
repeatedly trying to get it to respond. When you finally get it unlocked, the
whole interface is just &lt;em&gt;fiddly&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;The other issue was the data quality. There were some nights when I’d been
woken up, sometimes even getting up and moving around, and it just didn’t show
it in the data. If it can’t even get whether I’m asleep right, can I trust
anything else it says?&lt;/p&gt;
&lt;p&gt;I spent a while researching the best devices for sleep tracking. The Oura ring
came highly recommended, but it was expensive and required a subscription to
do anything useful. No thanks! The Apple Watch was consistently rated pretty
well, and I reasoned I could pick up a refurbished older unit. I’ve been
&lt;a href=&#34;https://chameth.com/apple-google-aligned-incentives/&#34;&gt;using an iPhone as my daily driver&lt;/a&gt; for
a while, so it’d fit right into my begrudged walled garden.&lt;/p&gt;
&lt;p&gt;The Series 10 has a significant advantage, though: it charges much quicker than
all the previous generations. On a 30-minute charge, the Series 10 can go from
0 to 60%; the 9 can only make it to 40%, and my old 5 a measly 30%. Shorter
charge times means I’m far less likely to leave it on charge and wander off
without it. In some ways the daily charging is more convenient than monthly: the
wireless charger sits on my desk, and I plop the watch on it for a little while
in the evening; I don’t need to dig out the weird pogo-pin connector that has
vanished sometime in the last four weeks, then carefully arrange it so it stays
attached.&lt;/p&gt;
&lt;h3 id=&#34;how-a-watch-maybe-saved-my-life&#34;&gt;How a watch maybe saved my life&lt;/h3&gt;
&lt;p&gt;One of the big features of the Apple Watch, like many other wearable devices,
is health and fitness tracking. I didn’t think much about this, beyond the
sleep data I wanted, at first. I’ve never had a particularly good relationship
with exercise&lt;sup id=&#34;fnref:2&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:2&#34; role=&#34;doc-noteref&#34;&gt;2&lt;/a&gt;&lt;/sup&gt;, but I do like some good statistics. I started going for
walks more often to get more data and see the graphs of VO2 max and HR recovery
gradually inch up. That wasn’t the most profound effect on my health, though…&lt;/p&gt;
&lt;!--more--&gt;
&lt;p&gt;The recent versions of the Apple Watch have a feature that monitors for sleep
apnea, a disorder where you don’t breathe properly during your sleep. I knew
I wasn’t sleeping great — that’s why I was paying attention to sleep tracking
data — but was still a bit surprised to get a notification from Apple Health
after wearing the watch for 30 days. It gives you a graph to print and take to
your doctor. So I diligently booked an appointment and a few weeks later went
to see my GP.&lt;/p&gt;
&lt;p&gt;The appointment went about as you’d expect: talking about referral to a sleep
centre for a study, and so on. Towards the end, the doctor took my blood
pressure (sleep apnea can be caused by, and can cause high blood pressure, in
a lovely little vicious cycle). I don’t think either of us expected anything;
it was just one of those standard checks for a related problem. After taking
the reading, the doctor looked at me and said, “I can’t let you leave with a
BP like this”. Yikes!&lt;/p&gt;
&lt;p&gt;Blood pressure readings are split into stages: normal is under 120 mmHg&lt;sup id=&#34;fnref:3&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:3&#34; role=&#34;doc-noteref&#34;&gt;3&lt;/a&gt;&lt;/sup&gt;
over 80 mmHg&lt;sup id=&#34;fnref:4&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:4&#34; role=&#34;doc-noteref&#34;&gt;4&lt;/a&gt;&lt;/sup&gt;, stage 1 is up to 140/90, stage 2 is up to 180/120,
and above is simply called “crisis”. Guess where I was? Also, fun fact:
depending on how exactly you count and attribute things, hypertension comes out
as the single largest cause of death in humans. It doesn’t kill you outright,
but contributes to strokes, coronary artery disease, heart failure, and lots
of other lovely things you don’t want on your CV.&lt;/p&gt;
&lt;p&gt;After doing a few more readings, it settled down to just under the “crisis”
stage and into the “holy crap, start treatment immediately” stage instead.
I won’t labour on much more about this, but things are definitely moving in
the right direction now&lt;sup id=&#34;fnref:5&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:5&#34; role=&#34;doc-noteref&#34;&gt;5&lt;/a&gt;&lt;/sup&gt;.&lt;/p&gt;
&lt;p&gt;While the Apple Watch didn’t literally save my life, it triggered the chain of
events that led to this diagnosis and treatment. Who knows what would have
happened had it remained undetected? Probably nothing good. Also, go check your
blood pressure! It’s simple to do and simple to treat if there is an issue,
but so many people are walking around with hypertension and not even realising.&lt;/p&gt;
&lt;aside class=&#34;update raised-box&#34;&gt;
  &lt;h5 class=&#34;plain-header&#34;&gt;Update 2025-09-09:&lt;/h5&gt;
  &lt;p&gt;Just a couple of hours after I published this post, Apple announced that they’re
adding hypertension notifications in the new Series 11 watch. It looks like
it will also be supported in Series 9 and Series 10 watches. They expect it to
notify more than one million people of unknown hypertension in the first year.&lt;/p&gt;
&lt;/aside&gt;
&lt;h3 id=&#34;building-gates-in-the-walled-garden&#34;&gt;Building gates in the walled garden&lt;/h3&gt;
&lt;p&gt;Even though the watch is arguably a life-saver, not everything is rosy.
It’s an Apple product, so you’re firmly locked in a walled garden, jealously
guarded by people wearing black turtlenecks. Fortunately, there are a few ways
to make it less painful.&lt;/p&gt;
&lt;p&gt;All the health and fitness data is stored in Apple Health. You can export data
as a big messy file, but it’s a very manual process to do so and the data format
is gnarly. Luckily, there’s an app for that!
&lt;a href=&#34;https://www.healthyapps.dev/&#34;&gt;Health Auto Export&lt;/a&gt; can, well, automatically
export health data. It does what it says on the tin. It can send the data to
Home Assistant, over MQTT, or dump it in some cloud file services, but I just
have it post it all to a REST endpoint on a service I wrote. Then I dump it all
in a database and can do whatever I want with it!&lt;sup id=&#34;fnref:6&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:6&#34; role=&#34;doc-noteref&#34;&gt;6&lt;/a&gt;&lt;/sup&gt;&lt;/p&gt;
&lt;p&gt;Another tool that’s more useful on the watch itself is Apple Shortcuts. This
is their no-code “if-this-then-that”-type thing. You can make automations or
shortcuts that run a number of tasks. I have a whole slew of them I access
via a complication&lt;sup id=&#34;fnref:7&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:7&#34; role=&#34;doc-noteref&#34;&gt;7&lt;/a&gt;&lt;/sup&gt; on my watch face: one which prompts for input and adds an
item to my to-do list (swiping to write letters is surprisingly not horrible),
one which lets me select from a bunch of pre-written ones (“charge kindle”,
“take laundry out in 1 hour”, type things), one to log my weight into Apple
Health, one which can open and close the blinds in my room, and so on. It’s
a surprisingly robust and easy-to-use system and offers just enough freedom
that I’m not constantly grating on the edge of the walled garden.&lt;/p&gt;
&lt;p&gt;Shortcuts being able to initiate arbitrary web requests is the real killer
feature for me. Anything I can’t do on the watch itself, I can just farm off
to a web server and connect it up with a shortcut. No need to learn Swift or
pay Apple for the privilege of being a developer! For a lot of things, like
controlling the blinds or adding to-do items, I already had a HTTP endpoint
available and exposed over Tailscale&lt;sup id=&#34;fnref:8&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:8&#34; role=&#34;doc-noteref&#34;&gt;8&lt;/a&gt;&lt;/sup&gt;. Adding it to the watch was just a case
of entering the right things in the Shortcuts app.&lt;/p&gt;
&lt;h3 id=&#34;daily-nitty-gritty&#34;&gt;Daily nitty-gritty&lt;/h3&gt;
&lt;p&gt;There are lots of other little bits and pieces that come up when using the watch
daily. I don’t think I can bundle them up into a pleasing narrative arc, so
instead please enjoy some disjointed paragraphs of observations.&lt;/p&gt;
&lt;p&gt;The Apple Watch has a lot of nagging abilities. It can notify you about your
fitness “rings”, prompt you to stand up every hour, count how many seconds
you wash your hands for, etc. I think I’d dislike these just on general
principle, but the way it does them is &lt;em&gt;so&lt;/em&gt; condescending it’s painful. I think
there’s probably a cultural divide issue here, but there is no way in British
English to say “Great job! You washed your hands for 30 seconds!” without
it sounding like you’re being amazingly sarcastic or like you’re talking to a
young child. So I turned all of that nonsense off. It’s meant to be a tool
not a wannabe life coach.&lt;/p&gt;
&lt;p&gt;You can access Maps directly on the watch and even do navigation. It works
really well. The navigation mode has some nice haptic feedback: it does a short
pulse as you’re approaching a turn, and then a long pulse at the actual turn.
I like it a lot more than having to dig out my phone or have the directions
read out. You get one pulse, glance down and see where you need to go, then it
reminds you a little later when it’s time to do it. It’s a delightful user
experience.&lt;/p&gt;
&lt;p&gt;Watchfaces aren’t quite so delightful. There’s a limited number of built-in
ones, and some are “exclusive” to the Ultra Series, and you can’t use them on
a peasant watch like a Series 10. Annoyingly, there’s not one that does
exactly what I want: a plain analogue clock with an inset date and four
complication slots around the outside. Instead, I have to use one of the slots
to show the date. There are third-party watchfaces, but they have issues.
Firstly, there’s no actual API for making watchfaces&lt;sup id=&#34;fnref:9&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:9&#34; role=&#34;doc-noteref&#34;&gt;9&lt;/a&gt;&lt;/sup&gt;, so what they do is
bodge it horribly by using a photo background that has fake widgets on it.
On top of that they’re almost universally subscription-based. Again, no
thanks&lt;sup id=&#34;fnref:10&#34;&gt;&lt;a class=&#34;footnote-ref&#34; href=&#34;#fn:10&#34; role=&#34;doc-noteref&#34;&gt;10&lt;/a&gt;&lt;/sup&gt;.&lt;/p&gt;
&lt;p&gt;The issue I had with the Smart Band triggering when I was sleeping is solved
trivially on an Apple Watch, by virtue of it having a physical button in the
crown. When you put it in sleep mode, you have to double-press the crown to
unlock it before it’ll do anything else. It hasn’t misfired once while I’ve
been using it.&lt;/p&gt;
&lt;figure class=&#34;image right&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/10-weeks-with-an-apple-watch-10/sleep.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/10-weeks-with-an-apple-watch-10/sleep.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/10-weeks-with-an-apple-watch-10/sleep.png&#34; alt=&#34;A graph showing sleep phases over time. There&amp;#39;s a noticeable transition form patchy data to more smooth data.&#34; loading=&#34;lazy&#34; width=&#34;284&#34; height=&#34;597&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;Sleep data; spot when I swapped devices!&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;Finally, a special mention for the gesture controls. If you raise the watch
it reliably wakes up (switching from a low refresh rate, dimmed screen to
an active, brighter one); you can then double-tap your index finger and thumb
together and it will scroll down or page through whatever you’re looking at.
The killer feature for this is navigating recipes: you can advance to the next
step in a recipe while your hands are covered in flour. It’s also handy for
reading notifications: when one pops up, you can double-tap to expand it, then,
when it gets to the bottom, it’ll outline the default button (often “Dismiss”)
and you can double-tap again to click it.&lt;/p&gt;
&lt;h3 id=&#34;the-verdict&#34;&gt;The verdict&lt;/h3&gt;
&lt;p&gt;I normally don’t like writing an actual labelled conclusion, but it feels
like one is needed here! Overall, I’m happy with the watch. The daily
charging doesn’t bother me, the data gathered seems reliable, the health
monitoring has obviously paid dividends already, and the walled garden isn’t
&lt;em&gt;too&lt;/em&gt; chafing. It’s a straight upgrade over my old Smart Band, and I think
it was worth the cost.&lt;/p&gt;
&lt;p&gt;The original reason for getting the watch was better sleep tracking, though,
so how well did it do? I’m much happier with the data: it seems to more
accurately represent when I was awake in the night, and overall the sleep
phases just seem to make more sense. You can see in the graph that the old
data switched frequently between phases, and they didn’t quite line up for
some reason; towards the right when the Apple Watch is supplying the data
instead there’s a much more consistent pattern of sleep phases that repeat
over the course of the night.&lt;/p&gt;
&lt;p&gt;I’m not going to advocate that you go out and buy one, though. I know my
requirements and usage aren’t typical, and I’ve also not got experience with
any recent Android Wear alternatives or the new version of the Pebble watch
that’s coming soon. You should definitely get your blood pressure checked,
though!&lt;/p&gt;
&lt;div class=&#34;footnotes&#34; role=&#34;doc-endnotes&#34;&gt;
&lt;hr/&gt;
&lt;ol&gt;
&lt;li id=&#34;fn:1&#34;&gt;
&lt;p&gt;OK, it’s more like 14 now, it’s taken a while for this post to make its
way from my brain into text. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:1&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:2&#34;&gt;
&lt;p&gt;Exercise for the sake of exercising just seems so overwhelmingly
tedious and boring to me. And other types of exercise generally require
social interaction, coordinating with people, and so on. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:2&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:3&#34;&gt;
&lt;p&gt;Who decided to use “millimetres of mercury displaced” as a unit? You
can’t just put random chemical symbols in units! That’s not how this works! &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:3&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:4&#34;&gt;
&lt;p&gt;Blood pressure readings have two parts: systolic (the pressure when the
heart is beating) and diastolic (the pressure between those beats). They’re
generally presented with the systolic reading on top and the diastolic reading
below, and read as “X over Y”. Now you know what some of the random numbers
they shout in medical shows mean! Yay learning! &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:4&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:5&#34;&gt;
&lt;p&gt;No thanks to how much salt is in everything. I’m pretty sure I’ve had at
least twice the recommended daily amount of salt in a single serving before.
Don’t even get me started on the things that are “low salt” but are still full
of sodium from other sources. I don’t have a problem with ionic compounds, I
have a problem with sodium! &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:5&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:6&#34;&gt;
&lt;p&gt;This mainly looks like drawing graphs that are slightly different to
the graphs in the Apple Health graphs, for reasons I’m not sure I can explain.
Making graphs is fun, OK? &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:6&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:7&#34;&gt;
&lt;p&gt;Complications are basically just home screen widgets, but with a fancy
name because they’re on a watch. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:7&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:8&#34;&gt;
&lt;p&gt;Tailscale actually causes me some problems here: everything works fine
when the watch is connected to my phone, as the phone handles the Tailscale
part, but if I’m not carrying my phone the watch will try to connect over
WiFi directly and doesn’t understand anything about Tailscale. It happens
infrequently enough that I’ll just live with it; it’s not much worse than
having no signal on a phone. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:8&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:9&#34;&gt;
&lt;p&gt;Yay walled gardens… &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:9&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;li id=&#34;fn:10&#34;&gt;
&lt;p&gt;I don’t object to subscribing to things in general, but it has to be
something that’s worth the ongoing cost and offers something in return for
the subscription. A watchface doesn’t need enough ongoing maintenance to
justify subscribing to it, it’s just a cash grab. &lt;a class=&#34;footnote-backref&#34; href=&#34;#fnref:10&#34; role=&#34;doc-backlink&#34;&gt;↩︎&lt;/a&gt;&lt;/p&gt;
&lt;/li&gt;
&lt;/ol&gt;
&lt;/div&gt;
</content>
    </entry>
</feed>
