Author: valerauko

A way to extract an image from Firefox

The problem I faced: I was scrolling through a hashtag‘s timeline in Tweetdeck, when I spotted a nice image. I wanted to retweet it, but that failed: turns out the tweet was deleted in the meanwhile. This usually means that either the artist themselves deleted the tweet for some reason, or it was stolen in the first place and (by some miracle) it was moderated.

In this case it seems to have been the latter, so finding the image through the author’s profile was not an option. As Tweetdeck displays images as CSS backgrounds in the timeline, right-click “Open image in new tab” was not an option. Since the tweet was deleted, its URL was invalidated too, so I couldn’t give that to Saucenao or similar to find matches either.

However, while digging through the Firefox Dev Tools, I noticed that the context menu when right clicking the URL of the background-image had an item “Copy image data URL”. This turned out to be just what I needed.

Pasting the copied (data blob) URL to the address bar I got the image that I could magnify so that I could decipher the artist’s signature on it. (It turned out to have been a partial image so Saucenao couldn’t help either.) After a few tries I found the artist’s profile and there the original post. Yay.


Adding Grafana annotations based on Flux CD events

Earlier this year I wrote about adding Grafana annotations based on Argo CD events. Since this year I actually got around testing out Flux some more, it was natural to follow up with adding some Grafana annotations based on Flux events.


ClojureDartの第一印象

Clojureの文法でFlutterが書けると聞いた時、これだ!と思った。ClojureDartはただClojureの文法をDartに変換するツールよりも、Flutterがメインだと感じた(個人的にDartもそうだと思っている)。ClojureDartはすごく短時間で「やるぞ」の発表から実際にだれでも試せるような形に発展した。あとからコミットログ見返すと、もっと前から作っていたらしいけど。

最近モバイルアプリ手掛けることになって、プロトタイプ作るにClojureDart試すことにした。困ったことはいろいろとあったが、後悔はしていない。

black and brown dart board

Clojure multimethods and derivation

I’ve known about Clojure multimethods of course, but I never really used them much. I didn’t really have data that I’d need polymorphism like multimethods to handle, and when I did need something like that I’d use protocols. However protocols dispatch based on class, so when I faced the problem of handling ActivityPub objects that are all maps, it was time for defmulti to save the day.

red yellow and green abstract painting

Structured logging in Clojure

The first time I ran into “structured logging” was way, way back when I first started working on kitsune. Back then I went with the approach of using a Logback Formatter (the JacksonJsonFormatter) to log Clojure maps as JSON. This was nice because I didn’t have to do anything to “transform” the logs further, but had the quite significant downside that logs weren’t really human readable anymore. This plus that that log processors like Loki and CloudWatch can easily parse huge amounts of “traditional” text logs made me pretty much forget about structured logging until recently.

That is until in a thread on the clojurians slack about logging someone mentioned mulog, a structured logging library that caught my attention. I guess maybe from a traditional Clojure background it would’ve been natural to end up with taoensso/timbre at this point, but I never did that bit (though I do have it as an indirect dependency).


キーボードの感想文です

いろいろと秋田。飽きた。ここ2年はlogicoolのG613をキーボードとして使っていたが、今年のブラックフライデーをきっかけに買い換えようと決めた。最大の理由はやっぱりキーの不調。キーが反応しなかったり、多重に反応したりして、タイポが多発していた。またスタート?スーパー?キーは爆死していて一切反応しなかった。前者はまだbackspaceという神機能でなんとかなったけど、スタートキーはUbuntuだとActivitiesを起動させるショートカットで重宝なのでないと困る(Windowsだとalt-tabみたいなものかな?)

さて買い換えるのもまた簡単じゃない。まず日本語配列であーる。英語で打つことも少なくないないが、日常の業務などでは日本語入力が当たり前でレイアウトに慣れている(変換・無変換キーとか)。また、同時に最低限2端末に接続ができること。仕事用のPCにはBluetoothで、私用PCにはBluetoothもしくは直に指すUSBで。3端末同時に行けると助かる。最後に、とんでもない金額ではないこと。キーボードに出す金は1.5万で上限、それもかなりかけた気分になる。

この条件のキーボード見つけるまではかなり苦戦した。その最大の理由はAmazonの検索はゴミである点にはあるが、検索の過程はキーボード自体に関係ないので省略する。最終的に落ち着いたのはまたlogi製ではあるが、K855という製品だ。


スマート電球の第一印象

スマート電球っていいね… と思っちゃった。わざわざベッドから起きなくても消せるし、スマホから操作もできるし、遠距離で点けたり消したりできるし、明度も調整できるし、強いでしょう?とか思いながらも結局金出すほどやりたいことでもなかった。そして今年の夏、ようつべでルームツアーやインテリア動画にハマった時期に紹介の動画を見たら結局衝動買いしちゃった。なぜかというとその辺飲みに行った店の内観がめっちゃササって、それっぽくできるじゃない?と思ったから。


The Weave GitOps UI for Flux

Unlike Argo, Flux has no built-in UI. CD tools should be invisible most of the time, just quietly running in the back, getting changes in the cluster. This is fine for “most of the time” when there are no changes to the applications I’m making myself or the cluster itself. It can just look at the various helm charts and other (git) sources and deploying the changes as configured. It’s nice that I can be sure that my cluster has the latest possible versions of everything running within 10-15 minutes of release (depending on the Flux interval configured) without ever touching kubectl.


How do foreign keys work in MariaDB system versioned tables?

When I read about the system versioned (and bitemporal) tables in MariaDB, I was both surprised and delighted. This kind of data versioning is thought of as standard in the “immutable” databases that are big in Clojureland, such as Datomic and XTDB. On the other hand, these databases in Clojureland are usually EAVT based and not the “usual” relational kind. After a little thinking I could think of a bunch of really tricky issues that could arise from system versioning (eg having a by-default immutable log of all changes to some piece of data) in a relational context. The first being foreign keys.

If you create a foreign key in MariaDB without any further specifiers, it assumes ON UPDATE RESTRICT ON DELETE RESTRICT, meaning no referenced key could be changed and no referenced row could be deleted. Just consider this: if there’s a row in some table referencing a row in another, system versioned table, can the row in the system versioned “parent” table be deleted? After all the referenced version of the row will still exist… Or in a similar scenario if the “child” row is system versioned and updated to now reference a different row, will both of those referenced rows be RESTRICTed? After all, both referencing rows will still exist… Of course I had to try.

brown-and-white clocks

自分でアドカレを作ってみた

アドカレのブログでアドカレ作った話を書くのはさすがにちょっとメタすぎる気もするが、学ぶことは少なくなかったのでまとめる。思いの外スムーズにいったこともあって、小規模ながらもおもしろかった。