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Happy end-of-2024! It’s been a pretty good year overall. I’m thankful. There’s no way that I’ll be able to remember and carve out the time around New Years to write this, so here’s some end-of-year roundup, ahead of schedule! Running This was my biggest year for running on record: 687 miles as of today. I think the biggest difference with this year was just that nothing stood in the way of my being pretty consistent and putting in the miles: the weather has been mild, I haven’t had any major injuries, and long runs have felt pretty good. I was happy to hit a half-marathon PR (1:36:21), but my performance in 5Ks was far short of the goal of sub-20 – partly because Brooklyn’s wonderful 5K series was run at the peak of summer, with multiple races at over 85°F. I learned the value of good lightweight running gear: Bakline’s singlets and Goodr sunglasses were super helpful in getting me through the summer. Work Val Town raised a seed round and hired a bunch of excellent people. We moved...
6 months ago

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Reading Zanzibar

Google published Zanzibar: Google’s Consistent, Global Authorization System in 2019. It describes a system for authorization – enforcing who can do what – which maxes out both flexibility and scalability. Google has lots of different apps that rely on Zanzibar, and bigger scale than practically any other company, so it needed Zanzibar. The Zanzibar paper made quite a stir. There are at least four companies that advertise products as being inspired by or based on Zanzibar. It says a lot for everyone to loudly reference this paper on homepages and marketing materials: companies aren’t advertising their own innovation as much as simply saying they’re following the gospel. A short list of companies & OSS products I found: Companies WorkOS FGA Authzed auth0 FGA Ory Permify Open source Ory Keto (Go) Warrant (Go) probably the basis for WorkOS FGA, since WorkOS acquired Warrant. SpiceDB (Go) the basis for Authzed. Permify (Go) OpenFGA (Go) the basis of auth0 FGA. I read the paper, and have a few notes, but the Google Zanzibar Paper, annotated by AuthZed is the same thing from a real domain expert (albeit one who works for one of these companies), so read that too, or instead. Features My brief summary is that the Zanzibar paper describes the features of the system succinctly, and those features are really appealing. They’ve figured out a few primitives from which developers can build really flexible authorization rules for almost any kind of application. They avoid making assumptions about ID formats, or any particular relations, or how groups are set up. It’s abstract and beautiful. The gist of the system is: Objects: things in your data model, like documents Users: needs no explanation Namespaces: for isolating applications Usersets: groups of users Userset rewrite rules: allow usersets to inherit from each other or have other kinds of set relationships Tuples, which are like (object)#(relation)@(user), and are sort of the core ‘rule’ construct for saying who can access what There’s then a neat configuration language which looks like this in an example: name: "doc" relation { name: "owner"} relation { name: "editor" userset_rewrite { union { child { _this f } } child { computed_userset { relation: "owner" } } relation { name: "viewer" userset_rewrite { union { child {_this f} } child { computed_userset & relation: "editor" 3 } child { tuple_to_userset { tupleset { relation: "parent" } computed_userset { object: $TUPLE_USERSET_OBJECT # parent folder relation: "viewer" } } } } } } It’s pretty neat. At this point in the paper I was sold on Zanzibar: I could see this as being a much nicer way to represent authorization than burying it in a bunch of queries. Specifications & Implementation details And then the paper discusses specifications: how much scale it can handle, and how it manages consistency. This is where it becomes much more noticeably Googley. So, with Google’s scale and international footprint, all of their services need to be globally distributed. So Zanzibar is a distributed system, and it is also a system that needs good consistency guarantees so that it avoid the “new enemy” problem, nobody is able to access resources that they shouldn’t, and applications that are relying on Zanzibar can get a consistent view of its data. Pages 5-11 are about this challenge, and it is a big one with a complex, high-end solution, and a lot of details that are very specific to Google. Most noticeably, Zanzibar is built with Spanner Google’s distributed database, and Spanner has the ability to order timestamps using TrueTime, which relies on atomic clocks and GPS antennae: this is not standard equipment for a server. Even CockroachDB, which is explicitly modeled off of Spanner, can’t rely on having GPS & atomic clocks around so it has to take a very different approach. But this time accuracy idea is pretty central to Zanzibar’s idea of zookies, which are sort of like tokens that get sent around in its API and indicate what time reference the client expects so that a follow-up response doesn’t accidentally include stale data. To achieve scalability, Zanzibar is also a multi-server architecture: there are aclservers, watchservers, a Leopard indexing system that creates compressed skip list-based representations of usersets. There’s also a clever solution to the caching & hot-spot problem, in which certain objects or tuples will get lots of requests all at once so their database shard gets overwhelmed. Conclusions Zanzibar is two things: A flexible, relationship-based access control model A system to provide that model to applications at enormous scale and with consistency guarantees My impressions of these things match with AuthZed’s writeup so I’ll just quote & link them: There seems to be a lot of confusion about Zanzibar. Some people think all relationship-based access control is “Zanzibar”. This section really brings to light that the ReBAC concepts have already been explored in depth, and that Zanzibar is really the scaling achievement of bringing those concepts to Google’s scale needs. link And Zookies are very clearly important to Google. They get a significant amount of attention in the paper and are called out as a critical component in the conclusion. Why then do so many of the Zanzibar-like solutions that are cropping up give them essentially no thought? link I finished the paper having absorbed a lot of tricky ideas about how to solve the distributed-consistency problems, and if I were to describe Zanzibar, those would be a big part of the story. But maybe that’s not what people mean when they say Zanzibar, and it’s more a description of features? I did find that Permify has a zookie-like Snap Token, AuthZed/SpiceDB has ZedTokens, and Warrant has Warrant-Tokens. Whereas OpenFGA doesn’t have anything like zookies and neither does Ory Keto. So it’s kind of mixed on whether these Zanzibar-inspired products have Zanzibar-inspired implementations, or focus more on exposing the same API surface. For my own needs, zookies and distributed consistency to the degree described in the Zanzibar paper are overkill. There’s no way that we’d deploy a sharded five-server system for authorization when the main application is doing just fine with single-instance Postgres. I want the API surface that Zanzibar describes, but would trade some scalability for simplicity. Or use a third-party service for authorization. Ideally, I wish there was something like these products but smaller, or delivered as a library rather than a server.

2 months ago 13 votes
Recently

I watched a large part of All Watched Over By Machines of Loving Grace this month. This also counts as a “listening” item, because the theme song, “Baby Love Child” by Pizzicato Five, is also spectacular. Guitar Moves is a good series of interviews by Matt Sweeney, who I mostly know via his involvement in Bonnie Prince Billy. It’s a really cool format. I like how he interviews guitarists with recognizable sounds, and you get to see how little they need to play to sound just like themselves. The episode with St. Vincent is excellent too: she’s one of my guitar heroes: check out the guitar solo in Just The Same But Brand New, or her version of Dig a Pony. I also watched No Other Land. Everyone should watch No Other Land. AI thoughts roundup I don’t have a conclusion. Really, that’s my current state: ambivalence. I acknowledge that these tools are incredibly powerful, I’ve even started incorporating them into my work in certain limited ways (low-stakes code like POCs and unit tests seem like an ideal use case), but I absolutely hate them. I hate the way they’ve taken over the software industry, I hate how they make me feel while I’m using them, and I hate the human-intelligence-insulting postulation that a glorified Excel spreadsheet can do what I can but better. Nolan Lawson: AI ambivalence As I always say, the purpose of the system is what it does. Or, in this case, how I think about AI stuff is mostly affected by how people use AI stuff, and how people use AI stuff is a real mixed bag. There’s the tidal wave of spam, the aesthetic of fascism, the low-effort marketing materials with nonsense images, the non-consensual AI porn. I see all of the bad stuff every day both online and in the odd subway ad. The good stuff seems pretty theoretical, though: the press releases about AI-driven medical advances never seem to break into the real world. The stories about engineers 10x’ing their ability seem pretty mixed: we’re already at the hangover-and-regret phase with programmers bemoaning how they’ve generated so much slop and lost so much knowledge. Anyway, I’m mildly optimistic about the potential! But it’s a lot like crypto in that you could theoretically use the technology for something good but most people loudly used it for bad stuff, and people including me judged it based on what it did. AI has to start doing some good stuff soon. Potential isn’t enough. I think one thing chatGPT’s invention has revealed is how many people - including some very important people in society - find just basic reading and writing to be laborious and cumbersome to perform, and how oddly closely that type of strained literacy correlates with having other shitty opinions. From mtsw on Bluesky, about this story about Andrew Cuomo using ChatGPT to half-assedly write a policy platform. Right off the bat I should say that judging people for their level of literacy reeks of classism and so on. My own ability to read & write has a lot to do with my place in society: I went to good schools, had a stable home life, and smart parents. However, “the way that society was set up” kind of evened this out. Extremely social people with cultural capital and chiseled jawlines and biceps would get their rewards, and people like… myself, we would get rewarded for literacy and critical thinking. When one group needed the other, it was usually some kind of payment or partnership: Cuomo pays his scriptwriter, the TV show creator pays the actors. And some people can do both sides of the equation. But LLMs definitely indicate that people do not like this deal. Whew, they don’t like writing, but they also don’t like paying the writers or reading what they write. Maybe they could rejigger the system so that they could do it all. They have ideas for music and art but no interest in learning about music, practicing instruments, going to art school, or concentrating on a task for a long time, so why not generate it all? Why not, well - there are reasons, those reasons being that the generated output usually passes their own vibe check but once someone who looks closely at things or reads all the words encounters it, everyone points at the slop and it’s embarrassing. (Cuomo will never be embarrassed) Plus, you’re always going to get average results by asking a device that is incapable of creativity or thought. Also, you’ll miss out on the human experience of creating. And you’ll be indirectly feeding output data into training data for future LLMs, consequentially making their output worse. (Cuomo does not care about consequences) Colophon update I’ve moved the images for this website to Bunny (that’s an affiliate link, here’s a non-affiliate link if that’s what you prefer). When I initially moved my photos to this website, I set them up with Amazon S3 for storage and CloudFront to serve them with a CDN. Using AWS is painful for me, so I moved them to Cloudflare R2, which is Cloudflare’s equivalent to S3, and Cloudflare as a CDN. Thanks to owning my own domains, swapping out image hosts is pretty quick: switching to Bunny took all of five minutes. So what’s the deal with Bunny? Partly I’ve become a little more negative on Cloudflare and R2: I think Cloudflare’s technology is neat, but R2 has iffy reliability and Cloudflare has iffy politics. I’m also intrigued by diversifying my dependencies geographically. Bunny is a Slovenian company, and my email is from an Australian company. This probably won’t have any practical effect, but it feels kind of good for obvious reasons to even minutely hedge my bets here. So far Bunny has been great. They don’t support the S3 protocol but they do support SFTP, which works just as well for my purposes and works great with the beautiful Transmit app. Before, with R2, I was using the significantly less beautiful Cyberduck application because Cloudflare R2 doesn’t support all of the S3 protocol. It seems to be just as fast as Cloudflare was, too. And I’m somewhat reassured by the prospect of paying Bunny. I don’t like the feeling of getting “free” services like I can from Cloudflare. I want that customer relationship. Reading Then again, pop culture is powerful, and even the dumbest marketing both affects and reflects it. Busch Light’s can holder shaped like a cup that holds beer is dumb, which is fine, because most beer promos are. But the fact that the brand frames it as a functional, masculine alternative to Stanley’s H2.0 Flowstate affirms a similarly retrograde outlook on gender roles to the one that young American men are seeking out on the political right. From my friend Dave’s article about Busch Light’s weird attempt to riff on the Stanley Tumbler trend. I was once a loyal listener of the Chapo Trap House podcast, but fell off of it in 2020 when their support of Bernie Sanders led them to be jerks about Elizabeth Warren. But reading this Vanity Fair article about the cohosts of the podcast endeared them to me a bit. “Like to thank” is linguistic phlegm. “I’d like to thank the Academy.” They’d “like to thank” me. Well I’d like to be 6’3” and drive a G Wagon, thanks. I’d like you to accept my novella. I’d like to quit paying three dollars to Submittable every time I want to send a story out. The world is full of actions I would like to do. The most direct way to say thank you is just to say it: “thank you, name, for doing X.” “I’d like to thank” is a performative thanks, a thanks with a smirk and a blink, eyeing for extra credit. Just because people say it in their award show acceptance speeches doesn’t mean you should say it, too. In fact, that’s the reason you shouldn’t say it. Loved this article “Close reading my rejections” from friend of the blog Barrett Hathcock.

2 months ago 11 votes
Tidbyt without the company

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It’s a super low-resolution, internet-connected, wood-paneled display that I wrote a review of it back in 2022. It’s been on my shelf for years now, showing the time, weather, warning me when the UV is going to be high. In 2023 I used it as an excuse to learn some Rust, to render custom graphics. It’s a toy, a distraction, a worry stone for me to work on when I need something open-ended and low-stakes. Anyway, the company that made the Tidbyt is no more. They got acquihired by Modal, a company that makes serverless AI compute hosting. So, they aren’t making devices right now, and the blog post promises that their cloud services will keep working. I don’t hold anything against the Tidbyt team: in fact, our Val Town office was coincidentally right next to theirs in a WeWork, and we met in real life! They’re very nice folks, and were doing so much with a small team. Lots of respect to them. Modal made a smart choice acquiring Tidbyt. But realistically, it’s time to make sure my device doesn’t become e-waste. The Tidbyt is ready for this One of the biggest critiques of the Tidbyt was that it was just an LED matrix and an ESP chip. You could buy an LED matrix on Sparkfun, the ESP, a power supply, some wood for the enclosure, and you’d have your own DIY Tidbyt. Maybe you could do it for half the price! But that’s also a strength. The Tidbyt is not some custom SoC with an exotic custom software stack and boutique hardware. It is what it looks like: a neat combination of commonplace parts. That makes it kind of future-proof and flexible. The first step is to replace the firmware. Tidbyt’s stock firmware routes all of its requests through the Tidbyt company’s servers. I want to eliminate that hop. Replacing the firmware Thankfully, Tidbyt published their ‘HDK’, which is an open source version of their stock firmware. It’s remarkably simple: It connects to Wifi It downloads a WebP image from a URL It displays that WebP image The HDK contains the code to do this stuff. There’s very little code required, but it does drag in a WebP decoder, Wifi library, and a library for running the LED matrix. But, setting up the HDK I ran into issues both small and large: it had issues with HTTPS URLs and Wifi passwords that contain spaces. Plus nobody has been added as a contributor to the HDK repository, so Pull Requests aren’t being accepted and it hasn’t had a change in 7 months. But the community came to the rescue with tronbyt’s firmware-http, a fork of the HDK that fixes every issue I experienced. Open source works! So back in 2022 I included this chart of the Tidbyt network: With an updated HDK, this workflow is a lot simpler. Instead of sending images to the Tidbyt servers and those Tidbyt servers delivering them to my device, the device makes requests directly of the server that generates the images. Replacing pixlet The Tidbyt team wrote pixlet, a little framework for generating pixel graphics that the Tidbyt displays. It lets you define a React-like tree of components - some text in a stack, a rectangle, images, and so on - and does all of the layout and rendering. The tronbyt community also forked pixlet and are actively developing it, which is fantastic. But this part of the stack I really never liked. That’s why I spent so much time reimplementing it in Rust and JavaScript. Partly it’s the language - pixlet apps are written in starlark, which is kind of an outgrowth of the Bazel build system from Google. Starlark is sort of like Python, but isn’t actually compatible with anything in the Python ecosystem. It’s very niche, limited, and overall just weird. I think I understand why Tidbyt would choose Starlark - it’s fast and has hermetic execution - making it safe to run untrusted Starlark programs because they can’t access the filesystem, network, or even the system clock without being given explicit controlled APIs to do those things. If you’re building a cloud service that runs a lot of untrusted user code, dictating that code is all Starlark is a really good cheat code - I know firsthand how hard it is to run untrusted JavaScript. But I’m not building a cloud service full of untrusted code. People who are self-hosting their Tidbyt devices (dozens of us!) don’t benefit from the tradeoffs of the Starlark language. They’d be better off with something normal. I rewrote pixlet again It’s called indiepixel and it’s a Python reimplementation of pixlet. It supports almost the entire pixlet API, and comes with the added benefit of being Python. You can use Python modules! You can read from the filesystem, parse CSVs, do all of your usual Python stuff. You can embed it in a Python application to render some graphics. What does indiepixel do currently? Renders text in the glorious retro BDF pixel font format. Renders pixelated pie charts, rectangles, and boxes. Supports animation for its WebP outputs. Provides a nice UI for browsing your selection of screens. It’ll probably never be finished, but it works well enough to power my Tidbyt. I’m running indiepixel on a free Render server instance, but it should run pretty much the same on any Python-compatible hosting: the only tricky dependency is Pillow, which it uses for image parsing and rendering. My free time for computer-oriented side projects has been limited, due to other commitments and an intention to get offline on the weekends. I’ve been sewing, biking, and running more. So I really want a side project I can enjoy, and indiepixel has fit the bill. It’s really satisfying to implement a new widget and see it rendered in blocky 64x32 pixels. The Pillow image rendering library for Python is mostly wonderful and very powerful. Why Python? Why is indiepixel written in Python? Well - I learned from tidbyt-rs that Rust would be an awkward fit as a scripting language for rendering graphics. The well-known Rust complexities around memory management made simple things difficult for me, which would make them totally unacceptable for others. Besides the attraction of being able to compile a small binary that might be able to run on the Tidbyt itself, Rust didn’t have many other advantages. The Pillow module really is such an advantage for Python. JavaScript doesn’t have a real alternative: there’s sharp, a great module for image conversion, but nothing that has such a great canvas interface. node-canvas is fine, but it doesn’t support WebP or animation, which are critical features for this project. I also wanted a test out the amazing new Python tooling that Astral is cooking up, like uv. I now have a better grasp of the Python ecosystem than I did a few months ago, and it’s optimistic but mixed. uv is amazing, but Python has a lot of legacy cruft around packaging. People are critical of NPM, but I think it did benefit from being established after PyPI and learning from its lessons. Thank you Steven Loria for a PR that fixed everything and made it all work and saved me months of tweaking settings. The graphic I watercolored that Tidbyt a while while ago and have been seriously dragging my feet on finishing this blog post. Sometimes the watercolor-illustration wags the technical-blog-post dog’s tail? Anyway, it’s a callback to that little world, with some small tweaks: this time I thought it’d be nice to have it be both watercolored and interactive. That ‘cybernetic’ feel. The secret recipe: a nice palette from lospec, creating a black & white mask of areas in Affinity Photo and vectorizing it with potrace, and then just some JavaScript that recolors based on hover handling. If you’re using the Tidbyt or some similar pixel-displaying device, try out indiepixel! It’s niche and has required a silly amount of effort to generate a glorified weather clock in my apartment, but it was a fun time chasing another interest.

2 months ago 34 votes
Recently

Reading Whether it’s cryptocurrency scammers mining with FOSS compute resources or Google engineers too lazy to design their software properly or Silicon Valley ripping off all the data they can get their hands on at everyone else’s expense… I am sick and tired of having all of these costs externalized directly into my fucking face. Drew DeVault on the annoyance and cost of AI scrapers. I share some of that pain: Val Town is routinely hammered by some AI company’s poorly-coded scraping bot. I think it’s like this for everyone, and it’s hard to tell if AI companies even care that everyone hates them. And perhaps most recently, when a person who publishes their work under a free license discovers that work has been used by tech mega-giants to train extractive, exploitative large language models? Wait, no, not like that. Molly White wrote a more positive article about the LLM scraping problem, but I have my doubts about its positivity. For example, she suggests that Wikimedia’s approach with “Wikimedia Enterprise” gives LLM companies a way to scrape the site without creating too much cost. But that doesn’t seem like it’s working. The problem is that these companies really truly do not care. Harberger taxes represent an elegant theoretical solution that fails in practice for immobile property. Just as mobile home residents face exploitation through sudden ground rent increases, property owners under a Harberger system would face similar hold-up problems. This creates an impossible dilemma: pay increasingly burdensome taxes or surrender investments at below-market values. Progress and Poverty, a blog about Georgism, has this post about Herberger taxes, which are a super neat idea. The gist is that you would be in charge of saying how much your house is worth, but the added wrinkle is that by saying a price you are bound to be open to selling your house at that price. So if you go too low, someone will buy it, or too high, and you’re paying too much in taxes. It’s clever but doesn’t work, and the analysis points to the vital difference between housing and other goods: that buying, selling, and moving between houses is anything but simple. I’ve always been a little skeptical of the line that the AI crowd feels contempt for artists, or that such a sense is particularly widespread—because certainly they all do not!—but it’s hard to take away any other impression from a trend so widely cheered in its halls as AI Ghiblification. Brian Merchant on the OpenAI Studio Ghibli ‘trend’ is a good read. I can’t stop thinking that AI is in danger of being right-wing coded, the examples of this, like the horrifying White House tweet mentioned in that article, are multiplying. I feel bad when I recoil to innocent usage of the tool by good people who just want something cute. It is kind of fine, on the micro level. But with context, it’s so bad in so many ways. Already the joy and attachment I’ve felt to the graphic style is fading as more shitty Studio Ghibli knockoffs have been created in the last month than in all of the studio’s work. Two days later, at a state dinner in the White House, Mark gets another chance to speak with Xi. In Mandarin, he asks Xi if he’ll do him the honor of naming his unborn child. Xi refuses. Careless People was a good read. It’s devastating for Zuckerberg, Joel Kaplan, and Sheryl Sandberg, as well as a bunch of global leaders who are eager to provide tax loopholes for Facebook. Perhaps the only person who ends the book as a hero is President Obama, who sees through it all. In a March 26 Slack message, Lavingia also suggested that the agency should do away with paper forms entirely, aiming for “full digitization.” “There are over 400 vet-facing forms that the VA supports, and only about 10 percent of those are digitized,” says a VA worker, noting that digitizing forms “can take years because of the sensitivity of the data” they contain. Additionally, many veterans are elderly and prefer using paper forms because they lack the technical skills to navigate digital platforms. “Many vets don’t have computers or can’t see at all,” they say. “My skin is crawling thinking about the nonchalantness of this guy.” Perhaps because of proximity, the story that Sahil Lavingia has been working for DOGE seems important. It was a relief when a few other people noticed it and started retelling the story to the tech sphere, like Dan Brown’s “Gumroad is not open source” and Ernie Smith’s “Gunkroad”, but I have to nitpick on the structure here: using a non-compliant open source license is not the headline, collaborating with fascists and carelessly endangering disabled veterans is. Listening Septet by John Carroll Kirby I saw John Carroll Kirby play at Public Records and have been listening to them constantly ever since. The music is such a paradox: the components sound like elevator music or incredibly cheesy jazz if you listen to a few seconds, but if you keep listening it’s a unique, deep sound. Sierra Tracks by Vega Trails More new jazz! Mammoth Hands and Portico Quartet overlap with Vega Trails, which is a beautiful minimalist band. Watching This short video with John Wilson was great. He says a bit about having a real physical video camera, not just a phone, which reminded me of an old post of mine, Carrying a Camera.

2 months ago 31 votes
Personal tools

I used to make little applications just for myself. Sixteen years ago (oof) I wrote a habit tracking application, and a keylogger that let me keep track of when I was using a computer, and generate some pretty charts. I’ve taken a long break from those kinds of things. I love my hobbies, but they’ve drifted toward the non-technical, and the idea of keeping a server online for a fun project is unappealing (which is something that I hope Val Town, where I work, fixes). Some folks maintain whole ‘homelab’ setups and run Kubernetes in their basement. Not me, at least for now. But I have been tiptoeing back into some little custom tools that only I use, with a focus on just my own computing experience. Here’s a quick tour. Hammerspoon Hammerspoon is an extremely powerful scripting tool for macOS that lets you write custom keyboard shortcuts, UIs, and more with the very friendly little language Lua. Right now my Hammerspoon configuration is very simple, but I think I’ll use it for a lot more as time progresses. Here it is: hs.hotkey.bind({"cmd", "shift"}, "return", function() local frontmost = hs.application.frontmostApplication() if frontmost:name() == "Ghostty" then frontmost:hide() else hs.application.launchOrFocus("Ghostty") end end) Not much! But I recently switched to Ghostty as my terminal, and I heavily relied on iTerm2’s global show/hide shortcut. Ghostty doesn’t have an equivalent, and Mikael Henriksson suggested a script like this in GitHub discussions, so I ran with it. Hammerspoon can do practically anything, so it’ll probably be useful for other stuff too. SwiftBar I review a lot of PRs these days. I wanted an easy way to see how many were in my review queue and go to them quickly. So, this script runs with SwiftBar, which is a flexible way to put any script’s output into your menu bar. It uses the GitHub CLI to list the issues, and jq to massage that output into a friendly list of issues, which I can click on to go directly to the issue on GitHub. #!/bin/bash # <xbar.title>GitHub PR Reviews</xbar.title> # <xbar.version>v0.0</xbar.version> # <xbar.author>Tom MacWright</xbar.author> # <xbar.author.github>tmcw</xbar.author.github> # <xbar.desc>Displays PRs that you need to review</xbar.desc> # <xbar.image></xbar.image> # <xbar.dependencies>Bash GNU AWK</xbar.dependencies> # <xbar.abouturl></xbar.abouturl> DATA=$(gh search prs --state=open -R val-town/val.town --review-requested=@me --json url,title,number,author) echo "$(echo "$DATA" | jq 'length') PR" echo '---' echo "$DATA" | jq -c '.[]' | while IFS= read -r pr; do TITLE=$(echo "$pr" | jq -r '.title') AUTHOR=$(echo "$pr" | jq -r '.author.login') URL=$(echo "$pr" | jq -r '.url') echo "$TITLE ($AUTHOR) | href=$URL" done Tampermonkey Tampermonkey is essentially a twist on Greasemonkey: both let you run your own JavaScript on anybody’s webpage. Sidenote: Greasemonkey was created by Aaron Boodman, who went on to write Replicache, which I used in Placemark, and is now working on Zero, the successor to Replicache. Anyway, I have a few fancy credit cards which have ‘offers’ which only work if you ‘activate’ them. This is an annoying dark pattern! And there’s a solution to it - CardPointers - but I neither spend enough nor care enough about points hacking to justify the cost. Plus, I’d like to know what code is running on my bank website. So, Tampermonkey to the rescue! I wrote userscripts for Chase, American Express, and Citi. You can check them out on this Gist but I strongly recommend to read through all the code because of the afore-mentioned risks around running untrusted code on your bank account’s website! Obsidian Freeform This is a plugin for Obsidian, the notetaking tool that I use every day. Freeform is pretty cool, if I can say so myself (I wrote it), but could be much better. The development experience is lackluster because you can’t preview output at the same time as writing code: you have to toggle between the two states. I’ll fix that eventually, or perhaps Obsidian will add new API that makes it all work. I use Freeform for a lot of private health & financial data, almost always with an Observable Plot visualization as an eventual output. For example, when I was switching banks and one of the considerations was mortgage discounts in case I ever buy a house (ha 😢), it was fun to chart out the % discounts versus the required AUM. It’s been really nice to have this kind of visualization as ‘just another document’ in my notetaking app. Doesn’t need another server, and Obsidian is pretty secure and private.

2 months ago 38 votes

More in programming

Digital hygiene: Emails

Email is your most important online account, so keep it clean.

12 hours ago 4 votes
Building a container orchestrator

Kubernetes is not exactly the most fun piece of technology around. Learning it isn’t easy, and learning the surrounding ecosystem is even harder. Even those who have managed to tame it are still afraid of getting paged by an ETCD cluster corruption, a Kubelet certificate expiration, or the DNS breaking down (and somehow, it’s always the DNS). Samuel Sianipar If you’re like me, the thought of making your own orchestrator has crossed your mind a few times. The result would, of course, be a magical piece of technology that is both simple to learn and wouldn’t break down every weekend. Sadly, the task seems daunting. Kubernetes is a multi-million lines of code project which has been worked on for more than a decade. The good thing is someone wrote a book that can serve as a good starting point to explore the idea of building our own container orchestrator. This book is named “Build an Orchestrator in Go”, written by Tim Boring, published by Manning. The tasks The basic unit of our container orchestrator is called a “task”. A task represents a single container. It contains configuration data, like the container’s name, image and exposed ports. Most importantly, it indicates the container state, and so acts as a state machine. The state of a task can be Pending, Scheduled, Running, Completed or Failed. Each task will need to interact with a container runtime, through a client. In the book, we use Docker (aka Moby). The client will get its configuration from the task and then proceed to pull the image, create the container and start it. When it is time to finish the task, it will stop the container and remove it. The workers Above the task, we have workers. Each machine in the cluster runs a worker. Workers expose an API through which they receive commands. Those commands are added to a queue to be processed asynchronously. When the queue gets processed, the worker will start or stop tasks using the container client. In addition to exposing the ability to start and stop tasks, the worker must be able to list all the tasks running on it. This demands keeping a task database in the worker’s memory and updating it every time a task change’s state. The worker also needs to be able to provide information about its resources, like the available CPU and memory. The book suggests reading the /proc Linux file system using goprocinfo, but since I use a Mac, I used gopsutil. The manager On top of our cluster of workers, we have the manager. The manager also exposes an API, which allows us to start, stop, and list tasks on the cluster. Every time we want to create a new task, the manager will call a scheduler component. The scheduler has to list the workers that can accept more tasks, assign them a score by suitability and return the best one. When this is done, the manager will send the work to be done using the worker’s API. In the book, the author also suggests that the manager component should keep track of every tasks state by performing regular health checks. Health checks typically consist of querying an HTTP endpoint (i.e. /ready) and checking if it returns 200. In case a health check fails, the manager asks the worker to restart the task. I’m not sure if I agree with this idea. This could lead to the manager and worker having differing opinions about a task state. It will also cause scaling issues: the manager workload will have to grow linearly as we add tasks, and not just when we add workers. As far as I know, in Kubernetes, Kubelet (the equivalent of the worker here) is responsible for performing health checks. The CLI The last part of the project is to create a CLI to make sure our new orchestrator can be used without having to resort to firing up curl. The CLI needs to implement the following features: start a worker start a manager run a task in the cluster stop a task get the task status get the worker node status Using cobra makes this part fairly straightforward. It lets you create very modern feeling command-line apps, with properly formatted help commands and easy argument parsing. Once this is done, we almost have a fully functional orchestrator. We just need to add authentication. And maybe some kind of DaemonSet implementation would be nice. And a way to handle mounting volumes…

16 hours ago 2 votes
Bugs I fixed in SumatraPDF

Unexamined life is not worth living said Socrates. I don’t know about that but to become a better, faster, more productive programmer it pays to examine what makes you un-productive. Fixing bugs is one of those un-productive activities. You have to fix them but it would be even better if you didn’t write them in the first place. Therefore it’s good to reflect after fixing a bug. Why did the bug happen? Could I have done something to not write the bug in the first place? If I did write the bug, could I do something to diagnose or fix it faster? This seems like a great idea that I wasn’t doing. Until now. Here’s a random selection of bugs I found and fixed in SumatraPDF, with some reflections. SumatraPDF is a C++ win32 Windows app. It’s a small, fast, open-source, multi-format PDF/eBook/Comic Book reader. To keep the app small and fast I generally avoid using other people’s code. As a result most code is mine and most bugs are mine. Let’s reflect on those bugs. TabWidth doesn’t work A user reported that TabWidth advanced setting doesn’t work in 3.5.2 but worked in 3.4.6. I looked at the code and indeed: the setting was not used anywhere. The fix was to use it. Why did the bug happen? It was a refactoring. I heavily refactored tabs control. Somehow during the rewrite I forgot to use the advanced setting when creating the new tabs control, even though I did write the code to support it in the control. I guess you could call it sloppiness. How could I not write the bug? I could review the changes more carefully. There’s no-one else working on this project so there’s no one else to do additional code reviews. I typically do a code review by myself with webdiff but let’s face it: reviewing changes right after writing them is the worst possible time. I’m biased to think that the code I just wrote is correct and I’m often mentally exhausted. Maybe I should adopt a process when I review changes made yesterday with fresh, un-tired eyes? How could I detect the bug earlier?. 3.5.2 release happened over a year ago. Could I have found it sooner? I knew I was refactoring tabs code. I knew I have a setting for changing the look of tabs. If I connected the dots at the time, I could have tested if the setting still works. I don’t make releases too often. I could do more testing before each release and at the very least verify all advanced settings work as expected. The real problem In retrospect, I shouldn’t have implemented that feature at all. I like Sumatra’s customizability and I think it’s non-trivial contributor to it’s popularity but it took over a year for someone to notice and report that particular bug. It’s clear it’s not a frequently used feature. I implemented it because someone asked and it was easy. I should have said no to that particular request. Fix printing crash by correctly ref-counting engine Bugs can crash your program. Users rarely report crashes even though I did put effort into making it easy. When I a crash happens I have a crash handler that saves the diagnostic info to a file and I show a message box asking users to report the crash and with a press of a button I launch a notepad with diagnostic info and a browser with a page describing how to submit that as a GitHub issue. The other button is to ignore my pleas for help. Most users overwhelmingly choose to ignore. I know that because I also have crash reporting system that sends me a crash report. I get thousands of crash reports for every crash reported by the user. Therefore I’m convinced that the single most impactful thing for making software that doesn’t crash is to have a crash reporting system, look at the crashes and fix them. This is not a perfect system because all I have is a call stack of crashed thread, info about the computer and very limited logs. Nevertheless, sometimes all it takes is a look at the crash call stack and inspection of the code. I saw a crash in printing code which I fixed after some code inspection. The clue was that I was accessing a seemingly destroyed instance of Engine. That was easy to diagnose because I just refactored the code to add ref-counting to Engine so it was easy to connect the dots. I’m not a fan of ref-counting. It’s easy to mess up ref-counting (add too many refs, which leads to memory leaks or too many releases which leads to premature destruction). I’ve seen codebases where developers were crazy in love with ref-counting: every little thing, even objects with obvious lifetimes. In contrast,, that was the first ref-counted object in over 100k loc of SumatraPDF code. It was necessary in this case because I would potentially hand off the object to a printing thread so its lifetime could outlast the lifetime of the window for which it was created. How could I not write the bug? It’s another case of sloppiness but I don’t feel bad. I think the bug existed there before the refactoring and this is the hard part about programming: complex interactions between distant, in space and time, parts of the program. Again, more time spent reviewing the change could have prevented it. As a bonus, I managed to simplify the logic a bit. Writing software is an incremental process. I could feel bad about not writing the perfect code from the beginning but I choose to enjoy the process of finding and implementing improvements. Making the code and the program better over time. Tracking down a chm thumbnail crash Not all crashes can be fixed given information in crash report. I saw a report with crash related to creating a thumbnail crash. I couldn’t figure out why it crashes but I could add more logging to help figure out the issue if it happens again. If it doesn’t happen again, then I win. If it does happen again, I will have more context in the log to help me figure out the issue. Update: I did fix the crash. Fix crash when viewing favorites menu A user reported a crash. I was able to reproduce the crash and fix it. This is the bast case scenario: a bug report with instructions to reproduce a crash. If I can reproduce the crash when running debug build under the debugger, it’s typically very easy to figure out the problem and fix it. In this case I’ve recently implemented an improved version of StrVec (vector of strings) class. It had a compatibility bug compared to previous implementation in that StrVec::InsertAt(0) into an empty vector would crash. Arguably it’s not a correct usage but existing code used it so I’ve added support to InsertAt() at the end of vector. How could I not write the bug? I should have written a unit test (which I did in the fix). I don’t blindly advocate unit tests. Writing tests has a productivity cost but for such low-level, relatively tricky code, unit tests are good. I don’t feel too bad about it. I did write lots of tests for StrVec and arguably this particular usage of InsertAt() was borderline correct so it didn’t occur to me to test that condition. Use after free I saw a crash in crash reports, close to DeleteThumbnailForFile(). I looked at the code: if (!fs->favorites->IsEmpty()) { // only hide documents with favorites gFileHistory.MarkFileInexistent(fs->filePath, true); } else { gFileHistory.Remove(fs); DeleteDisplayState(fs); } DeleteThumbnailForFile(fs->filePath); I immediately spotted suspicious part: we call DeleteDisplayState(fs) and then might use fs->filePath. I looked at DeleteDisplayState and it does, in fact, deletes fs and all its data, including filePath. So we use freed data in a classic use after free bug. The fix was simple: make a copy of fs->filePath before calling DeleteDisplayState and use that. How could I not write the bug? Same story: be more careful when reviewing the changes, test the changes more. If I fail that, crash reporting saves my ass. The bug didn’t last more than a few days and affected only one user. I immediately fixed it and published an update. Summary of being more productive and writing bug free software If many people use your software, a crash reporting system is a must. Crashes happen and few of them are reported by users. Code reviews can catch bugs but they are also costly and reviewing your own code right after you write it is not a good time. You’re tired and biased to think your code is correct. Maybe reviewing the code a day after, with fresh eyes, would be better. I don’t know, I haven’t tried it.

23 hours ago 1 votes
An Analysis of Links From The White House’s “Wire” Website

A little while back I heard about the White House launching their version of a Drudge Report style website called White House Wire. According to Axios, a White House official said the site’s purpose was to serve as “a place for supporters of the president’s agenda to get the real news all in one place”. So a link blog, if you will. As a self-professed connoisseur of websites and link blogs, this got me thinking: “I wonder what kind of links they’re considering as ‘real news’ and what they’re linking to?” So I decided to do quick analysis using Quadratic, a programmable spreadsheet where you can write code and return values to a 2d interface of rows and columns. I wrote some JavaScript to: Fetch the HTML page at whitehouse.gov/wire Parse it with cheerio Select all the external links on the page Return a list of links and their headline text In a few minutes I had a quick analysis of what kind of links were on the page: This immediately sparked my curiosity to know more about the meta information around the links, like: If you grouped all the links together, which sites get linked to the most? What kind of interesting data could you pull from the headlines they’re writing, like the most frequently used words? What if you did this analysis, but with snapshots of the website over time (rather than just the current moment)? So I got to building. Quadratic today doesn’t yet have the ability for your spreadsheet to run in the background on a schedule and append data. So I had to look elsewhere for a little extra functionality. My mind went to val.town which lets you write little scripts that can 1) run on a schedule (cron), 2) store information (blobs), and 3) retrieve stored information via their API. After a quick read of their docs, I figured out how to write a little script that’ll run once a day, scrape the site, and save the resulting HTML page in their key/value storage. From there, I was back to Quadratic writing code to talk to val.town’s API and retrieve my HTML, parse it, and turn it into good, structured data. There were some things I had to do, like: Fine-tune how I select all the editorial links on the page from the source HTML (I didn’t want, for example, to include external links to the White House’s social pages which appear on every page). This required a little finessing, but I eventually got a collection of links that corresponded to what I was seeing on the page. Parse the links and pull out the top-level domains so I could group links by domain occurrence. Create charts and graphs to visualize the structured data I had created. Selfish plug: Quadratic made this all super easy, as I could program in JavaScript and use third-party tools like tldts to do the analysis, all while visualizing my output on a 2d grid in real-time which made for a super fast feedback loop! Once I got all that done, I just had to sit back and wait for the HTML snapshots to begin accumulating! It’s been about a month and a half since I started this and I have about fifty days worth of data. The results? Here’s the top 10 domains that the White House Wire links to (by occurrence), from May 8 to June 24, 2025: youtube.com (133) foxnews.com (72) thepostmillennial.com (67) foxbusiness.com (66) breitbart.com (64) x.com (63) reuters.com (51) truthsocial.com (48) nypost.com (47) dailywire.com (36) From the links, here’s a word cloud of the most commonly recurring words in the link headlines: “trump” (343) “president” (145) “us” (134) “big” (131) “bill” (127) “beautiful” (113) “trumps” (92) “one” (72) “million” (57) “house” (56) The data and these graphs are all in my spreadsheet, so I can open it up whenever I want to see the latest data and re-run my script to pull the latest from val.town. In response to the new data that comes in, the spreadsheet automatically parses it, turn it into links, and updates the graphs. Cool! If you want to check out the spreadsheet — sorry! My API key for val.town is in it (“secrets management” is on the roadmap). But I created a duplicate where I inlined the data from the API (rather than the code which dynamically pulls it) which you can check out here at your convenience. Email · Mastodon · Bluesky

yesterday 2 votes
AmigaGuide Reference Library

As I slowly but surely work towards the next release of my setcmd project for the Amiga (see the 68k branch for the gory details and my total noob-like C flailing around), I’ve made heavy use of documentation in the AmigaGuide format. Despite it’s age, it’s a great Amiga-native format and there’s a wealth of great information out there for things like the C API, as well as language guides and tutorials for tools like the Installer utility - and the AmigaGuide markup syntax itself. The only snag is, I had to have access to an Amiga (real or emulated), or install one of the various viewer programs on my laptops. Because like many, I spend a lot of time in a web browser and occasionally want to check something on my mobile phone, this is less than convenient. Fortunately, there’s a great AmigaGuideJS online viewer which renders AmigaGuide format documents using Javascript. I’ve started building up a collection of useful developer guides and other files in my own reference library so that I can access this documentation whenever I’m not at my Amiga or am coding in my “modern” dev environment. It’s really just for my own personal use, but I’ll be adding to it whenever I come across a useful piece of documentation so I hope it’s of some use to others as well! And on a related note, I now have a “unified” code-base so that SetCmd now builds and runs on 68k-based OS 3.x systems as well as OS 4.x PPC systems like my X5000. I need to: Tidy up my code and fix all the “TODO” stuff Update the Installer to run on OS 3.x systems Update the documentation Build a new package and upload to Aminet/OS4Depot Hopefully I’ll get that done in the next month or so. With the pressures of work and family life (and my other hobbies), progress has been a lot slower these last few years but I’m still really enjoying working on Amiga code and it’s great to have a fun personal project that’s there for me whenever I want to hack away at something for the sheer hell of it. I’ve learned a lot along the way and the AmigaOS is still an absolute joy to develop for. I even brought my X5000 to the most recent Kickstart Amiga User Group BBQ/meetup and had a fun day working on the code with fellow Amigans and enjoying some classic gaming & demos - there was also a MorphOS machine there, which I think will be my next target as the codebase is slowly becoming more portable. Just got to find some room in the “retro cave” now… This stuff is addictive :)

yesterday 4 votes