Though I often use [Zellij] as terminal multiplexer when working on remote machine, sometimes I need to switch to [byobu] for its feature of keeping session alive when I disconnect SSH.

One inconvenience with byobu is that, when running Helix inside it, the "copy to clipboard" feature (press Space then y) stops working. Only recently did I learn that one of the backends that Helix uses for the clipboard feature is "tmux", the same software under byobu's hood. It means that, when running in byobu, Helix should still be able to do "copy to clipboard", it is just a configuration matter that byobu disable the feature.

Here is how to make the "copy" works again, open ~/.config/byobu/profile.tmux file and add these lines:

In that last April, I made [journald-send], to serve as replacement for [systemd-python], for folks who want to write logs to journald, using native protocol.

It is a partial replacement, because it only offers the "write" part, not "read". That's enough because most of applications which want to talk with journald just need to "write". I made [journald-send] out of the frustration that systemd-python development seems to be stuck, the last release was on the beginning of 2023, when it is 2026 now, and the compatibility with Python 3.14 is uncertain. Even after I contributed some code to modernize the Python project structure, the core developers still seems to not rush to make a release.

I wrote [jounald-send] in Rust, aiming for Python 3.14 free-threaded (No GIL) mode. Because I only need to support "write" operation, I decide not to depend on the C libsystemd, and go further by using Rust pure libraries ([rustix] and [memfd]) to talk with Linux API. I learnt from [tracing-journald] for how to prepare data for journald protocol and which steps to do with the sockets. The difference is that [tracing-journald] is using libc and I use [rustix], [memfd].

After finishing [journald-send], I updated my other libraries [chameleon-log], [structlog-journald] to use journald-send under the hood. [chameleon-log] is for integrating [logbook] and [structlog-journald] is for integrating with [structlog].

In a previous post, ["Define UI comprising Dropdown in Blueprint for modern GTK apps"][dropdown-post], I presented how to use [DropDown][dropdown] in [Blueprint][blueprint]. Now we go with a bit more complex example, with ListView widget.

This is the UI where ListView is used, in my [CoBang][cobang] app:

It shows a list of WiFi network config, for which user will pick to generate QR code. The list is accompanied with a search box, via which user will type part of Wi-Fi name to narrow down the list, to quickly find the needed Wi-Fi network.

GTK is one of the GUI toolkits for building Linux desktop apps, notable for its modern visual look, and with some advanced developer experience features, like Inspector.

But one of the things that is still old-fashioned is its support for declarative UI. GTK allows developer to describe the UI separately from application code, but the language is XML which is too verbose, comparing to QT's QML or Slint. Fortunately, there is an new language, Blueprint, to describe UI for GTK app, which brings the same taste of QML, Slint to the table. But Blueprint is still young, not integrated to GTK yet (the files written in Blueprint must be compiled to Gtk.Builder XML) and the documentation is not rich enough.

This post shows you how to use Dropdown or other list widgets (like ListView, GridView) in Blueprint. The example use case and code is drawn from my application, CoBang.

List widgets follow Model-View-Controller pattern, to dislay a list of data with dynamic length. The widget is not used alone, but with other non-display components from GTK library:

I have used Incus-based containers for nearly a year. From Ubuntu 25.04, somethings weird happened, many commands just hang, not return.

This post spot the cause: AppArmor blocks sending signals on Ubuntu 25.04 host.

There is no true fix yet, there are two workarounds:

1. Disable apparmor_unconfined_restriction

Ubuntu comes with a default terminal emulator, GNOME Terminal. But due to the limit of the underlying vte, many users don't want to use it. If you want to set a different program as default terminal, so that you can invoke it with Ctrl + Alt + T, here is how to do it.

Determine the desktop file of your terminal, by searching in /usr/share/applications/ or ~/.local/share/applications/. For example, kitty has one at ~/.local/share/applications/kitty.desktop, Ghostty has one at /usr/share/applications/com.mitchellh.ghostty.desktop.

Edit the ~/.config/xdg-terminals.list file (create it if it does not exist). Add the name of the desktop file at the top. For example, here is mine:

Recently I heard about Nginx Unit, a piece of software which lets you run Python web application on production with less components. It's like you let Nginx run your Python code, no longer Nginx - Gunicorn separation. So I installed it and learned how to use, but the default setup is not convenient: You have to switch to root user too often. So I share extra steps of setup to save you from it.

Nginx Unit is not configured via file like Nginx. It is done via HTTP API, which is nice because Nginx Unit can get update with new configuration without restarting, although I don't know what is the benefit over using SIGHUP signal to trigger rereading. The API communication is done via Unix domain socket, leveraging Linux authentication for restricting access, which is very reasonable because we don't have to remember port, username and password. But the issue is that, the default setup makes the socket writable by root only.

The annoyance come from the combination of these factors:

GraphQL là một dạng thiết kế HTTP API được dùng rộng rãi. Mặt lợi của nó thì không cần bàn. Tuy nhiên mình và có thể các bạn cũng thấy hơi phiền vì nó dài dòng. Bài này sẽ giới thiệu một số phương tiện phần mềm để làm việc với nó thoải mái hơn, ở phía client.

Python: Cách dùng Pydantic để kiểm tra hợp lệ

Lấy ví dụ API của BirdWeather. Đây là kho dữ liệu của các trạm thu thập tiếng chim hót, phục vụ nghiên cứu nhận dạng chim từ tiếng hót. Ta sẽ gọi vào truy vấn stations để lấy danh sách các trạm. Một response mẫu sẽ trông như sau:

Bạn đã thích thú với Nushell, đã cài vào nhưng không thấy tính năng auto-complete? Đừng vội buồn. Đó là vì các file cài đặt Nushell hiện tại không kèm sẵn các script auto-complete. Bạn sẽ phải làm thêm tí việc tay chân để cài các script này vào.

Mặc dù yêu thích Nushell, mình phải thừa nhận rằng mức độ hỗ trợ auto-complete của Nushell chưa dồi dào bằng Fish. Nushell được thiết kế để nhận dữ liệu auto-complete từ cả các script chuyên dụng viết bằng Nu và từ cả phần mềm khác.

1. Nguồn từ phần mềm khác

Từ trong Nushell, gõ:

If we have Fish installed and try to install pretty new softwares via APT package manager (on Ubuntu), we may encounter this error:

Error: error processing archive /var/cache/apt/archives/just_1.35.0-1build1_amd64.deb (--unpack):

Error: error processing archive /var/cache/apt/archives/just_1.35.0-1build1_amd64.deb (--unpack):
 trying to overwrite '/usr/share/fish/completions/just.fish', which is also in package fish 4.0b1-1~oracular