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    <title>Chameth.com - posts like docker-automatic-nginx-proxy, g15-ram-upgrade, travel-toolkit, utility-user-stories, why-you-should-be-using-https</title>
    <subtitle>Personal homepage of Chris Smith</subtitle>
    <link href="https://chameth.com/feeds/posts/like/docker-automatic-nginx-proxy,g15-ram-upgrade,travel-toolkit,utility-user-stories,why-you-should-be-using-https/" rel="self"/>
    <link href="https://chameth.com/"/>
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    <updated>2026-01-29T00:00:00Z</updated>
    <id>https://chameth.com/</id>
    <author>
        <name>Chris Smith</name>
    </author>
    <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>Building a travel toolkit</title>
        <link href="https://chameth.com/travel-toolkit/"/>
        <updated>2025-01-02T00:00:00Z</updated>
        <id>https://chameth.com/travel-toolkit/</id>
        <content xml:lang="en" type="html">&lt;figure class=&#34;image left&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/travel-toolkit/bag.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/travel-toolkit/bag.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/travel-toolkit/bag.png&#34; alt=&#34;UGREEN Travel Accessories Bag&#34; loading=&#34;lazy&#34; width=&#34;365&#34; height=&#34;578&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;The container for my toolkit, a UGREEN “travel accessories” bag&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;For a while now, whenever I’ve traveled anywhere I’ve dumped a selection of tools
into my backpack just in case I need them. Originally this was mostly focused
around being able to open and fix my laptop if anything went wrong, but
over time has slowly expanded to include other useful tools.&lt;/p&gt;
&lt;p&gt;Repeatedly packing these tools and then returning them to where they belonged
was tedious, though. I couldn’t just leave them in the backpack as I often
needed them for non-travelling purposes, and I didn’t want to just buy duplicate
tools that spent most of their life a few meters away from each other, so I
ignored the problem and just dealt with the tedium.&lt;/p&gt;
&lt;p&gt;Eventually I acquired enough tools that — while not quite duplicates — I
wouldn’t miss often if they were kept in the backpack. Building on these I’ve
created a little travel toolkit that contains everything I might want (and
more) while away.&lt;/p&gt;
&lt;h3 id=&#34;the-base&#34;&gt;The base&lt;/h3&gt;
&lt;p&gt;The biggest challenge I had before was finding a screwdriver set. I have an
&lt;a href=&#34;https://www.ifixit.com/products/mako-driver-kit-64-precision-bits&#34;&gt;iFixit Mako&lt;/a&gt;
set that did the in-and-out-of-the-bag routine for several years. Nothing else
covered the range of drivers I wanted for generic electronic tinkering and
more chunky work. I finally found one in the form of a
&lt;a href=&#34;https://toolrebels.de/en/products/wera-tool-rebel-tool-check-plus-tr-edition&#34;&gt;Wera Tool-Check PLUS TR-Edition&lt;/a&gt;.
“TR” stands for “Tool Rebel” and is Wera’s “fan club” brand. Its signature
features over the normal Tool-Check PLUS are a fancy fabric case and a 152mm
bit extender; but it also comes with a much different set of bits, which is
why I picked it up.&lt;/p&gt;
&lt;!--more--&gt;
&lt;p&gt;Here’s a comparison&lt;/p&gt;
&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Type&lt;/th&gt;
&lt;th&gt;Standard version&lt;/th&gt;
&lt;th&gt;Tool Rebel edition&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;Phillips&lt;/td&gt;
&lt;td&gt;2x PH1&lt;br/&gt;3x PH2&lt;br/&gt;1x PH3&lt;/td&gt;
&lt;td&gt;1x PH00&lt;br/&gt;1x PH0&lt;br/&gt;1x PH1&lt;br/&gt;1x PH2&lt;br/&gt;1x PH3&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Pozidrive&lt;/td&gt;
&lt;td&gt;None&lt;/td&gt;
&lt;td&gt;1x PZ1&lt;br/&gt;3x PZ2&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Slotted&lt;/td&gt;
&lt;td&gt;1x 5.5mm&lt;/td&gt;
&lt;td&gt;1x 4mm&lt;br/&gt;1x 4.5mm&lt;br/&gt;2x 5.5mm&lt;br/&gt;1x 6.5mm&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Torx&lt;/td&gt;
&lt;td&gt;1x T10&lt;br/&gt;1x T15&lt;br/&gt;1x T20&lt;br/&gt;1x T25&lt;br/&gt;1x T30&lt;br/&gt;1x T40&lt;/td&gt;
&lt;td&gt;1x T10&lt;br/&gt;1x T15&lt;br/&gt;1x T20&lt;br/&gt;1x T25&lt;br/&gt;1x T30&lt;br/&gt;1x T40&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Security Torx&lt;/td&gt;
&lt;td&gt;1x T10&lt;br/&gt;1x T15&lt;br/&gt;1x T20&lt;br/&gt;1x T25&lt;br/&gt;1x T30&lt;/td&gt;
&lt;td&gt;1x T25&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Hex&lt;/td&gt;
&lt;td&gt;1x H3&lt;br/&gt;1x H4&lt;br/&gt;1x H5&lt;br/&gt;1x H6&lt;br/&gt;1x H8&lt;/td&gt;
&lt;td&gt;1x H1.5&lt;br/&gt;1x H2&lt;br/&gt;1x H2.5&lt;br/&gt;1x H3&lt;br/&gt;1x H4&lt;br/&gt;1x H6&lt;br/&gt;1x H8&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p&gt;There are only five bits present in the standard version that are missing in
the TR edition: 5mm hex (pretty uncommon) and four sizes of security torx (rare).
In exchange for those and the removal of a bunch of duplicates, you get two extra
phillips sizes (0 and 00, both very useful for electronics and spectacles),
some pozidrive bits (extremely common on random hardware/furniture/etc),
smaller hex bits (for electronics, 3D printers, and so on), and a few other
bits and pieces.&lt;/p&gt;
&lt;p&gt;Overall it’s a vastly superior selection for my needs. And while it doesn’t have
the full range of bits provided by the iFixit kit, it does cover almost
everything I’m ever actually likely to need while travelling, and it’s probably
around a third of the size.&lt;/p&gt;
&lt;p&gt;The other core part of the toolkit is the bag. I had a UGREEN “travel accessory”
bag hanging around unused, and noticed it was almost the exact right size for
the Tool-Check. Now, how many other tools could I stuff in there?&lt;/p&gt;
&lt;h3 id=&#34;all-the-tools&#34;&gt;All the tools&lt;/h3&gt;
&lt;figure class=&#34;image full&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/travel-toolkit/contents.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/travel-toolkit/contents.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/travel-toolkit/contents.jpg&#34; alt=&#34;The contents of my toolkit, spread out on a mat&#34; loading=&#34;lazy&#34; width=&#34;1024&#34; height=&#34;912&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;The array of tools that make up the travel toolkit&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;The kit can be broken down into a few sections:&lt;/p&gt;
&lt;h4 id=&#34;screwdriving&#34;&gt;Screwdriving&lt;/h4&gt;
&lt;ul&gt;
&lt;li&gt;The aforementioned Wera Tool-Check&lt;/li&gt;
&lt;li&gt;Its 152mm bit extender&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;I’ve talked enough about this already, I think, so I’ll spare you any additional
commentary on screwdrivers and bits.&lt;/p&gt;
&lt;h4 id=&#34;splitting-gripping-and-cutting&#34;&gt;Splitting, gripping and cutting&lt;/h4&gt;
&lt;ul&gt;
&lt;li&gt;Engineer tweezers&lt;/li&gt;
&lt;li&gt;Engineer mini snips&lt;/li&gt;
&lt;li&gt;Engineer mini screw removal pliers&lt;/li&gt;
&lt;li&gt;Knipex mini waterpump pliers&lt;/li&gt;
&lt;li&gt;Two iFixit spudgers (one metal, one plastic)&lt;/li&gt;
&lt;li&gt;iFixit jimmy&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;I have bigger or slightly different versions of these that stay in my normal
toolkit. The tweezers and snips are useful in a variety of situations,
and the spudgers are handy for getting inside laptops and other devices. The
pliers are less useful, but they’re one of those things where when you &lt;em&gt;do&lt;/em&gt;
need them there aren’t any good alternatives.&lt;/p&gt;
&lt;h4 id=&#34;sewing&#34;&gt;Sewing&lt;/h4&gt;
&lt;ul&gt;
&lt;li&gt;Two needles&lt;/li&gt;
&lt;li&gt;Some black thread&lt;/li&gt;
&lt;li&gt;Set of mini clips&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;You never know when you’re going to rip a seam in something. I find the clips a
lot less fiddly than using pins for keeping material in place when I’m trying to
sew.&lt;/p&gt;
&lt;h4 id=&#34;computering&#34;&gt;Computering&lt;/h4&gt;
&lt;ul&gt;
&lt;li&gt;Retractable ethernet cable&lt;/li&gt;
&lt;li&gt;RJ45 coupler&lt;/li&gt;
&lt;li&gt;USB-C to RJ45 adapter&lt;/li&gt;
&lt;li&gt;Dual USB-A and USB-C thumb drive, with an Arch ISO on it&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;Sometimes Wi-Fi just doesn’t cut it, or you need to fiddle with a router that
doesn’t expose its admin UI over Wi-Fi. The USB-C adapter is for use with my
phone, as it’s often easier to move that get the laptop where it needs to be.&lt;/p&gt;
&lt;p&gt;I can boot from the thumb drive into an Arch environment, and from there
reinstall my laptop from scratch if needed. There’s enough space left over so
it can be used to transfer files as well.&lt;/p&gt;
&lt;h4 id=&#34;miscellaneousing&#34;&gt;Miscellaneousing&lt;/h4&gt;
&lt;ul&gt;
&lt;li&gt;Fabric tape measure&lt;/li&gt;
&lt;li&gt;Spirit level&lt;/li&gt;
&lt;li&gt;Sharpie&lt;/li&gt;
&lt;li&gt;Superglue&lt;/li&gt;
&lt;li&gt;Spare batteries: 2 CR2032s, 2 AA, 2 AAA&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;I’m almost certain I won’t use the spirit level, but it’s tiny and I had a spare
so it went in. Everything else is just in the “generally handy to have”
category.&lt;/p&gt;
&lt;h3 id=&#34;putting-it-all-together&#34;&gt;Putting it all together&lt;/h3&gt;
&lt;figure class=&#34;image right&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/travel-toolkit/complete.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/travel-toolkit/complete.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/travel-toolkit/complete.png&#34; alt=&#34;The complete toolkit&#34; loading=&#34;lazy&#34; width=&#34;500&#34; height=&#34;506&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;The nicely-organised side of the toolkit&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;The Tool-Check PLUS fits almost perfectly into one side of the UGREEN bag,
leaving a little wiggle room along the side for the longer parts like spudgers.
The middle pockets can’t fit much in, but keep the batteries and sewing bits
out of the way. Everything else is in a big zip-up compartment in the other
side, which is slightly messy but still easy enough to dig through to find
whatever I need.&lt;/p&gt;
&lt;p&gt;The complete kit weighs in at around 1.2KG, so it’s not exactly lightweight,
but it goes in a bag with a heavy laptop and all of its peripherals so it’s
not as noticeable as it might otherwise be.&lt;/p&gt;
&lt;p&gt;It remains to be seen how much use I’ll actually get out of any of this. Maybe
I’ll put a bit of paper in so that I can track how often I use each tool…&lt;/p&gt;
</content>
    </entry>
    <entry>
        <title>Upgrading the RAM in a Dell G15 laptop</title>
        <link href="https://chameth.com/g15-ram-upgrade/"/>
        <updated>2023-07-29T00:00:00Z</updated>
        <id>https://chameth.com/g15-ram-upgrade/</id>
        <content xml:lang="en" type="html">&lt;figure class=&#34;image left&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/g15-ram-upgrade/g15.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/g15-ram-upgrade/g15.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/g15-ram-upgrade/g15.png&#34; alt=&#34;An open Dell G15 laptop&#34; loading=&#34;lazy&#34; width=&#34;580&#34; height=&#34;402&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;The Dell G15&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;I currently use a Dell G15 laptop for work. It has served me well for a little
over a year, but recently it has been struggling a little with my day-to-day
workload. It came with 32GB of RAM — the highest possible specification at the
time&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; — but that is apparently no longer enough for me.&lt;/p&gt;
&lt;p&gt;For a recent project, I was working on a Rust library used in an Android app.
That meant running the usual glut of Android tools (Android Studio, an emulator
and at least one Gradle daemon) alongside a normal IDE (IntelliJ IDEA). Throw
in a web browser and a couple of electron apps, and I often managed to
use all 32GB.&lt;/p&gt;
&lt;p&gt;When you start swapping memory out to an encrypted disk — even an SSD — it
doesn’t make for great performance. At first, I tried to work around this
by enabling the Linux out-of-memory (OOM) killer, but it turns out that it’s not
too good with Electron apps: it will kill the large browser process, but then
the small Electron wrapper will just respawn it.&lt;/p&gt;
&lt;!--more--&gt;
&lt;h3 id=&#34;can-it-be-upgraded-or-not&#34;&gt;Can it be upgraded or not?&lt;/h3&gt;
&lt;p&gt;The obvious solution to not having enough RAM is to add more RAM. A quick look
in the manual showed this might not be possible, though. The manual includes
the following “Memory specifications” table:&lt;/p&gt;
&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Description&lt;/th&gt;
&lt;th&gt;Values&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;Memory slots&lt;/td&gt;
&lt;td&gt;Two SODIMM slots&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Memory type&lt;/td&gt;
&lt;td&gt;DDR5&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Memory speed&lt;/td&gt;
&lt;td&gt;4800&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Maximum memory configuration&lt;/td&gt;
&lt;td&gt;32GB&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Minimum memory configuration&lt;/td&gt;
&lt;td&gt;8GB&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Memory size per slot&lt;/td&gt;
&lt;td&gt;8GB or 16GB&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Memory configurations supported&lt;/td&gt;
&lt;td&gt;&lt;ul&gt;&lt;li&gt;8 GB, 1 x 8 GB, DDR5, 4800 MHz&lt;/li&gt;&lt;li&gt;16 GB, 1 x 16 GB, DDR5, 4800 MHz&lt;/li&gt;&lt;li&gt;16 GB, 2 x 8 GB, DDR5, 4800 MHz, dual-channel&lt;/li&gt;&lt;li&gt;32 GB, 2 x 16 GB, DDR5, 4800 MHz, dual-channel&lt;/li&gt;&lt;/ul&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p&gt;That unambiguously says that an upgrade from 32GB is not possible. I gave up.&lt;/p&gt;
&lt;p&gt;Later though, I was complaining about memory issues to a friend, and he pointed
out a Dell forum thread where a couple of people claim to have successfully
installed dual-channel 32GB modules. Since the alternative was getting an
entire new PC after only a year, I decided to give it a go.&lt;/p&gt;
&lt;h3 id=&#34;the-upgrade-attempt&#34;&gt;The upgrade attempt&lt;/h3&gt;
&lt;p&gt;I ordered a pair of Crucial 32GB DDR5-4800 SODIMMs, and after they turned up
dismantled the laptop. The G15 comes apart pretty normally: there are uncovered
screws on the bottom holding the lower part of the case on. With those
removed and some gentle prying, it pops off, and you get access to the battery,
GPU and motherboard.&lt;/p&gt;
&lt;p&gt;The first thing I saw was this:&lt;/p&gt;
&lt;figure class=&#34;image full&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/g15-ram-upgrade/motherboard.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/g15-ram-upgrade/motherboard.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/g15-ram-upgrade/motherboard.jpg&#34; alt=&#34;The G15 motherboard, with a large &amp;#34;DDR5 8G/16G Only&amp;#34; label, and a smaller &amp;#34;DIMM B DDR5 8G/16G&amp;#34; label next to a SODIMM slot&#34; loading=&#34;lazy&#34; width=&#34;1536&#34; height=&#34;1300&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;The G15 motherboard adamantly proclaiming that it doesn’t want 32GB SODIMMs&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;Not one but two labels that indicate it will only accept 8GB or 16GB modules.
Oh well, what’s the worst that can happen?&lt;/p&gt;
&lt;h3 id=&#34;oops&#34;&gt;Oops?&lt;/h3&gt;
&lt;p&gt;I dutifully installed the new modules, reconnected the battery and put the
case back together. I pressed the power button, and… nothing. None of the
usual garish lights that immediately come on, no screen output, just a dead
laptop. After reading some more of the user manual, I found that there is a tiny
status LED on the side next to the ethernet port. Forcing the laptop to power
off and back on again, the status LED blinked a distress code at me: 2 amber
blinks, 4 white blinks. The manual says that is — unsurprisingly — a memory
fault.&lt;/p&gt;
&lt;p&gt;I figured at this point that the manual and labels on the motherboard were
probably right. I took the laptop apart again, reinstalled the original 2x16GB
modules, reassembled it, and pressed the power button. It didn’t boot. I don’t
spend a lot of time fiddling inside computers, but I’ve done it enough that
I’m reasonably confident I can’t entirely break a computer while swapping some
RAM modules. I took to Googling&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;, and found an interesting article that said
Dell laptops don’t like to boot after RAM changes unless you clear the CMOS by
popping out the battery for 15 minutes.&lt;/p&gt;
&lt;p&gt;I opened the laptop up, and looked around for the CMOS battery. There wasn’t
one. Turns out they don’t exist any more. I left the main battery disconnected
for a while to see if it would help, and it didn’t.&lt;/p&gt;
&lt;h3 id=&#34;unexpected-success&#34;&gt;Unexpected success&lt;/h3&gt;
&lt;p&gt;I started to get worried: if I couldn’t fix this, I wouldn’t be able to
work until I got a new PC, and that wasn’t really in my budget at the minute.
I sat reading old forum threads and help guides&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;, none of which were actually
useful. Out of nowhere, though, the laptop booted up.&lt;/p&gt;
&lt;p&gt;Naturally, I immediately shut the laptop down again, opened it up, and switched
back to the new RAM modules. Then I turned it on again and sat waiting. After
about 15 minutes of it looking totally dead, it turned on and showed a BIOS
warning about the hardware configuration being changed. It then booted perfectly
normally, and all 64GB of RAM was visible and usable.&lt;/p&gt;
&lt;p&gt;My theory is that the forum threads were right: Dell laptops are funny about
RAM upgrades. But somehow in removing the physical CMOS battery, they’ve kept
the same “you have to wait 15 minutes” behaviour just without any indication
that’s what’s happening. Regardless, I now have enough RAM even for the
greediest of IDEs and Electron apps.&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;Bizarrely, the maximum spec has &lt;em&gt;decreased&lt;/em&gt; to 16GB since then. &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;In the generic sense. I use &lt;a href=&#34;https://kagi.com/&#34;&gt;Kagi&lt;/a&gt; these days. &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;On my phone because, y’know, the laptop was busted. &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;/ol&gt;
&lt;/div&gt;
</content>
    </entry>
    <entry>
        <title>Docker reverse proxying, redux</title>
        <link href="https://chameth.com/docker-proxying-redux/"/>
        <updated>2022-12-06T00:00:00Z</updated>
        <id>https://chameth.com/docker-proxying-redux/</id>
        <content xml:lang="en" type="html">&lt;p&gt;Six years ago, &lt;a href=&#34;https://chameth.com/docker-automatic-nginx-proxy/&#34;&gt;I described&lt;/a&gt;
my system for configuring a reverse proxy for docker containers.
It involved six containers including a key-value store and a webserver.
Nothing in that system has persisted to this day. Don’t get me wrong – it
worked – but there were a lot of rough edges and areas for improvement.&lt;/p&gt;
&lt;h3 id=&#34;microservices-and-their-limitations&#34;&gt;Microservices and their limitations&lt;/h3&gt;
&lt;p&gt;My goal was to follow the UNIX philosophy of “do one thing and do it well”.
Unfortunately, that doesn’t really work when applied to network services that
have to interact with one and other. UNIX tools are built upon a common file
system and simple data passed over STDIN. Microservices don’t have that
shared foundation. You could make one:
companies that use microservices in anger often have a team that deals with
the “developer experience” of creating and using
microservices. But as a solo developer that’s not something I wanted to
spend my time doing.&lt;/p&gt;
&lt;!--more--&gt;
&lt;p&gt;This became very apparent when trying to debug issues. In the UNIX world,
if your series of commands piped together does something strange you can simply
echo the data at various stages. Not so much when that data is flying around
on a network, going into and out of things like etcd. Trying to figure out why
a certificate hadn’t been acquired was a case of searching through logs from
four containers, none of which had particularly good logging.
There are many ways to get insight into what’s
happening with microservices but, again, that’s not something I wanted to do myself.&lt;/p&gt;
&lt;p&gt;Over time, and with experience in other projects, I came to realise that
microservices only really make sense if you’re unable to deploy a monolith.
For tech companies this naturally happens when different teams
contribute to the same service: splitting it out into smaller services that
are wholly owned by individual teams makes sense. For solo developers,
that never happens. You can still gain the other benefits
of microservices – such as code separation and having clearly defined APIs –
by sticking to certain coding standards.&lt;/p&gt;
&lt;h3 id=&#34;proxy-inconveniences&#34;&gt;Proxy inconveniences&lt;/h3&gt;
&lt;p&gt;As well as being unhappy with the microservice nature of the solution,
I wasn’t pleased with nginx. If you requested an unknown domain, nginx
would use the first server block in its config to serve a response, instead
of sending an “unrecognised name” alert as I wanted. It was a minor issue, but
it irked me.&lt;/p&gt;
&lt;p&gt;So from nginx I switched to haproxy. It has a &lt;code&gt;strict-sni&lt;/code&gt; option when configuring
TLS connections which makes it behave properly. It also performs a lot better for
this type of workload than nginx. All was well for a while, but then I started getting alerts
that requests were occasionally failing. I couldn’t reproduce the issue, but
my nightly jobs to build and push containers managed to hit it nearly every
night, causing them to fail.&lt;/p&gt;
&lt;p&gt;After some investigation, I found that the haproxy developers had refactored
the header parsing code, and
neglected to properly reset flags when multiple requests were sent over the same
connection. There was a patch, but it wasn’t released. No problem, I thought,
I’ll just cherry-pick it onto the last release… Except that haproxy use
Git in the most convoluted manner I’ve ever seen – they have one
repository per release. This makes it harder to patch, but it also made me question
whether I trusted them to ship stable software: there were no tests for
the header parsing code (which is both fundamental and finicky,
the perfect target for tests), the source code management was weird, and they didn’t
seem in any rush to patch this bug.&lt;/p&gt;
&lt;p&gt;Not long after that issue, &lt;a href=&#34;https://greg.holmes.name/&#34;&gt;Greg&lt;/a&gt; managed to
encounter another bug where haproxy returned a 500 error whenever the
upstream server replied with a particular, perfectly valid, header.
The die was cast – it was time to move to something else.&lt;/p&gt;
&lt;h3 id=&#34;not-invented-here-syndrome&#34;&gt;Not Invented Here syndrome&lt;/h3&gt;
&lt;p&gt;Looking for a new solution, there were many more options than
back in 2016. I’m still convinced, however, that anything
exposed to the Internet should not have access to run docker containers.
It’s the modern equivalent of running a CGI script as root. That
single requirement eliminates most off-the-shelf solutions.
What do you do when nothing quite meets
your specific requirements? You make something yourself! My new solution has two
components: &lt;a href=&#34;https://github.com/csmith/dotege&#34;&gt;Dotege&lt;/a&gt; and
&lt;a href=&#34;https://github.com/csmith/centauri&#34;&gt;Centauri&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;Dotege is a replacement for the
microservices that monitored containers and obtained certificates. It’s fundamentally
a templating engine - whenever the containers change, it evaluates a
template and saves the result to disk. The template has access to details about
the containers, their labels, ports, and so on. Dotege can also obtain certificates
from Let’s Encrypt, and raise a signal against another
process whenever the template or certificates change. I used this to generate
the configuration and certificates used by haproxy for a while, and more recently
changed the template so that it works for Centauri.&lt;/p&gt;
&lt;p&gt;Centauri is my own reverse proxy. It’s configured using a simple text file
and can also obtain certificates from an ACME provider. It doesn’t serve static
content, has no knowledge about docker, and avoids the other bells and
whistles that adorn most reverse proxies. It also has good test
coverage to ensure that I don’t, say, accidentally break header parsing.&lt;/p&gt;
&lt;p&gt;As a software engineer I enjoy writing software, but I also enjoy running
simple, easy to understand software. That’s what I’ve achieved here: it’s
very easy to identify where the problem is if anything goes wrong, both are small
Go programs rather than vast sprawling C
monstrosities, and their interaction is primarily through a file written to disk
that can be inspected or edited as needed.&lt;/p&gt;
</content>
    </entry>
    <entry>
        <title>On the utility of user stories</title>
        <link href="https://chameth.com/utility-user-stories/"/>
        <updated>2021-10-16T00:00:00Z</updated>
        <id>https://chameth.com/utility-user-stories/</id>
        <content xml:lang="en" type="html">&lt;p&gt;User stories are a staple of most agile methodologies. You’d be hard-pressed to find
an experienced software developer that’s not come across them at some point in their
career. In case you haven’t, they look something like this:&lt;/p&gt;
&lt;blockquote&gt;
&lt;p&gt;As a frequent customer, &lt;br/&gt;
I want to be able to browse my previous orders, &lt;br/&gt;
So that I can quickly re-order products.&lt;/p&gt;
&lt;/blockquote&gt;
&lt;p&gt;They provide a persona (in this case “a frequent customer”), a goal (“browse my previous
orders”) and a reason (“so that I can quickly re-order products”). This fictitious user
story would probably rank among one of the better ones I’ve seen. More typically you end
up with something like:&lt;/p&gt;
&lt;blockquote&gt;
&lt;p&gt;As a user, &lt;br/&gt;
I want to be able to login,&lt;br/&gt;
So that I can browse while logged in.&lt;/p&gt;
&lt;/blockquote&gt;
&lt;p&gt;This doesn’t really provide a persona or any proper reasoning. It’s just a straight-forward
task pretending to be a user story. If this is written in an issue then it provides no
extra information over one that simply says “Allow users to login”. In fact, because it’s
expressed so awkwardly I’d argue that it’s worse.&lt;/p&gt;
&lt;!--more--&gt;
&lt;p&gt;This kind of task-disguised-as-a-user-story problem becomes more obvious when people try
to write technical tasks in the same way:&lt;/p&gt;
&lt;blockquote&gt;
&lt;p&gt;As a developer,&lt;br/&gt;
I want to refactor the JobFactory,&lt;br/&gt;
So that I can work with it more efficiently in the future.&lt;/p&gt;
&lt;/blockquote&gt;
&lt;p&gt;This just says “Refactor the JobFactory”. If you wrote that in a ticket you’d probably
feel bad for not describing it very well, but somehow when it’s dressed up as a user
story it feels more valuable.&lt;/p&gt;
&lt;h3 id=&#34;does-the-user-really-want-that&#34;&gt;Does the user really want that?&lt;/h3&gt;
&lt;p&gt;One thing that really irks me about user stories is that it lets you twist your
business objectives into sounding like they’re the user’s idea: the story becomes
a post-hoc justification for a task you decided was required.&lt;/p&gt;
&lt;p&gt;Say you’re making a mobile app for an online book store, and your team for whatever
reason has a target of increasing the number of users who view the daily book-of-the-day
offer. Maybe you do some interviews and users tell you they forget to check in each
day to see what the offer is. How can you funnel more users there?&lt;/p&gt;
&lt;blockquote&gt;
&lt;p&gt;As a mobile app user, &lt;br/&gt;
I want to receive a push notification whenever a new book-of-the-day is available, &lt;br/&gt;
So that I have the chance to buy the book.&lt;/p&gt;
&lt;/blockquote&gt;
&lt;p&gt;Some users probably do want such a thing, but I’d argue the vast majority of them
do not. Imagine if every app on your phone alerted you whenever there was a new
deal, or popped up a dialog whenever you went near a physical shop they had
vouchers for…&lt;/p&gt;
&lt;p&gt;Obviously in the cold reality of capitalism businesses make money by doing things
not strictly in the interests of users&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;. When written up like this it becomes so
painfully disingenuous, though. Despite writing a user story that starts with
the words “As a user”, you’re not really putting yourself in the user’s shoes.&lt;/p&gt;
&lt;h3 id=&#34;who-even-is-the-user&#34;&gt;Who even is the user?&lt;/h3&gt;
&lt;p&gt;One of the big benefits of user stories comes from using &lt;em&gt;personas&lt;/em&gt;
to describe users. It’s also one of the things that’s rarely actually done, at
least in my experience. Looking at Google Trends you can see the rise of searches
for “user story” as agile slowly takes over the world, but the movement in
searches about personas is very slight:&lt;/p&gt;
&lt;figure class=&#34;image center&#34;&gt;
  &lt;picture&gt;
      &lt;source srcset=&#34;https://chameth.com/utility-user-stories/google-trends-story-persona.avif&#34; type=&#34;image/avif&#34;/&gt;
      &lt;source srcset=&#34;https://chameth.com/utility-user-stories/google-trends-story-persona.webp&#34; type=&#34;image/webp&#34;/&gt;
      &lt;img src=&#34;https://chameth.com/utility-user-stories/google-trends-story-persona.png&#34; alt=&#34;Graph showing relative search frequency for user stories against user personas&#34; loading=&#34;lazy&#34; width=&#34;1000&#34; height=&#34;550&#34;/&gt;
  &lt;/picture&gt;
  &lt;figcaption&gt;&lt;p&gt;Graph showing relative search frequency for user stories against user personas&lt;/p&gt;
&lt;/figcaption&gt;
&lt;/figure&gt;
&lt;p&gt;A lot of the time stories are just written with “As a user”, or have some
adjectives tacked on to the start (“as a mobile user”, “as a logged-in user”).
The best I’ve ever seen in the wild was specifying the class of user like
in the example at the start: “as a frequent customer”, or “as a visually impaired user”.&lt;/p&gt;
&lt;p&gt;The problem with using these classes is it requires you to come up with them
when you’re writing the story. Maybe one day you think about visually impaired
users, but the next you don’t. Maybe Bob thinks about certain classes of users,
but Alice concentrates on different ones.&lt;/p&gt;
&lt;p&gt;The ideal way to solve this is to come up with personas that all the team
understand. For example:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Kiera is addicted to books. She reads across genres, and often buys books
to gift to her friends and family. She has piles and piles of books to
read, but that doesn’t stop her ordering more if she sees a good deal.
She likes receiving new books almost as much as reading them, and opts
for the fastest delivery available.&lt;/li&gt;
&lt;li&gt;Sharon is a slow, methodical reader. She buys one book at a time when she’s
close to finishing her current one, and gifts or resells her old books.
She almost exclusively reads Science Fiction, and will generally read
complete series from start to finish. She’s short-sighted and often
struggles when using mobile phones or computers.&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;You’d probably want 2-4 personas that collectively represent most facets of your
userbase. They can be a lot more fleshed out than these - if you search for
example user personas you’ll find many beautifully presented examples that
have complete backgrounds including hobbies, education levels, and so on.
Even with this minimal level of detail, though, I’d argue they’re more useful
than just writing things in a standard user story form.&lt;/p&gt;
&lt;p&gt;Thinking back to the story about push notifications, writing it to use one
of these two personas forces you to think about the trade-offs involved. Kiera
probably &lt;em&gt;would&lt;/em&gt; like a notification, but it would annoy and possibly confuse
Sharon. This then leads you down the path of considering how to accommodate
both types of user — maybe adding it as an option, or doing some fancy machine
learning, etc. The conversation is now focused around the users, rather than
steamrolling over them to reach a business objective.&lt;/p&gt;
&lt;h3 id=&#34;youre-holding-it-wrong&#34;&gt;You’re holding it wrong&lt;/h3&gt;
&lt;p&gt;The problems I’ve described are not a problem with user stories &lt;em&gt;per se&lt;/em&gt;, but
rather common issues with how they’re used. But there’s only so many times you
can tell people they’re holding a tool wrong before you have to accept that maybe
the tool was badly designed.&lt;/p&gt;
&lt;p&gt;Considering features from the perspective of multiple personas is the single
best thing you can possibly do to ensure you’re providing value to your users.
You don’t even need to write things in the typical user story style to benefit
from this.&lt;/p&gt;
&lt;p&gt;Tacking “As a user,” to the start of all your JIRA tickets isn’t being agile,
and isn’t good for users, even if it lets you tick a box somewhere. In some
cases this lip-service to users is actively detrimental to them. We should
be valuing users and personas over stilted templates and check-box exercises
(&lt;a href=&#34;https://agilemanifesto.org/&#34;&gt;remind you of anything?&lt;/a&gt;).&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;As a user, I want to pay more money for the things that I buy,
so that the company’s CEO can afford to go to space. &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>
</feed>
