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I was interested in learning about htmx, so I used it to improve the experience of posting comments on my blog.

It seems much of modern web development is structured around having a JavaScript program on the front-end (browser) which exchanges data encoded in JSON asynchronously with the back-end servers. htmx uses a novel (or throwback) approach: it asynchronously fetches snippets of HTML from the back-end, and splices the results into the live page. For example, a htmx-powered button may request a URI on the server, receive HTML in response, and then the button itself would be replaced by the resulting HTML, within the page.

I experimented with incorporating it into an existing, old-school CGI web app: IkiWiki, which I became a co-maintainer of this year, and powers my blog. Throughout this project I referred to the excellent book Server-Driven Web Apps with htmx.

Comment posting workflow

I really value blog comments, but the UX for posting them on my blog was a bit clunky. It went like this:

1. you load a given page (such as this blog post), which is a static HTML document. There's a link to add a comment to the page.

2. The link loads a new page which is generated dynamically and served back to you via CGI. This contains a HTML form for you to write your comment.

3. The form submits to the server via HTTP POST. IkiWiki validates the form content. Various static pages (in particular the one you started on, in Step 1) are regenerated.

4. the server response to the request in (3) is a HTTP 302 redirect, instructing the browser to go back to the page in Step 1.

First step: fetching a comment form

First, I wanted the "add a comment" link to present the edit box in the current page. This step was easiest: add four attributes to the "comment on this page" anchor tag:

hx-get="<CGI ENDPOINT GOES HERE>"

suppresses the normal behaviour of the tag, so clicking on it doesn't load a new page.

issues an asynchronous HTTP GET to the CGI end-point, which returns the full HTML document for the comment edit form

hx-select=".editcomment form"

extract the edit-comment form from within that document

hx-swap=beforeend and hx-target=".addcomment"

append (courtesy of beforeend) the form into the source page after the "add comment" anchor tag (.addcomment)

Now, clicking "comment on this page" loads in the edit-comment box below it without moving you away from the source page. All that without writing any new code!

Second step: handling previews

The old Preview Comment page

In the traditional workflow, clicking on "Preview" loaded a new page containing the edit form (but not the original page or any existing comments) with a rendering of the comment-in-progress below it. I wasn't originally interested in supporting the "Preview" feature, but I needed to for reasons I'll explain later.

Rather than load new pages, I wanted "Preview" to insert a rendering of the comment-in-progress being inserted into the current page's list of comments, marked up to indicate that it's a preview.

IkiWiki provides some templates which you can override to customise your site. I've long overridden page.tmpl, the template used for all pages. I needed to add a new empty div tag in order to have a "hook" to target with the previewed comment.

The rest of this was achieved with htmx attributes on the "Preview" button, similar to in the last step: hx-post to define a target URI when you click the button (and specify HTTP POST); hx-select to filter the resulting HTML and extract the comment; hx-target to specify where to insert it.

Now, clicking "Preview" does not leave the current page, but fetches a rendering of your comment-in-progress, and splices it into the comment list, appropriately marked up to be clear it's a preview.

Third step: handling submitted comments

IkiWiki is highly configurable, and many different things could happen once you post a comment.

On my personal blog, all comments are held for moderation before they are published. The page you were served after submitting a comment was rather bare-bones, a status message "Your comment will be posted after moderator review", without the original page content or comments.

I wanted your comment to appear in the page immediately, albeit marked up to indicate it was awaiting review. Since the traditional workflow didn't render or present your comment to you, I had to cheat.

handling moderated comments

Moderation message upon submitting a comment

One of my goals with this project was not to modify IkiWiki itself. I had to break this rule for moderated comments. When returning the "comment is moderated" page, IkiWiki uses HTTP status code 200, the same as for other scenarios. I wrote a tiny patch to return HTTP 202 (Accepted, but not processed) instead.

I now have to write some actual JavaScript. htmx emits the htmx:beforeSwap event after an AJAX call returns, but before the corresponding swap is performed. I wrote a function that is triggered on this event, filters for HTTP 202 responses, triggers the "Preview" button, and then alters the result to indicate a moderated, rather than previewed, comment. (That's why I bothered to implement previews). You can read the full function here: jon.js.

Summary

I've done barely any front-end web development for years and I found working with htmx to be an enjoyable experience.

You can leave a comment on this very blog post if you want to see it in action. I couldn't resist adding an easter egg: Brownie points if you can figure out what it is.

Adding htmx to an existing CGI-based website let me improve one of the workflows in a gracefully-degrading way (without JavaScript, the old method will continue to work fine) without modifying the existing application itself (well, almost) and without having to write very much code of my own at all: nearly all of the configuration was declarative.

Here's our bi-monthly update from KDE's personal information management applications team. This report covers progress made in September and October 2024.

Since the last report, 24 people have contributed over 1100 changes to the KDE PIM code base. We also released a two bugfix releases of the KDE PIM Suite with the Gear releases 24.08.1 and 24.08.2

Please note this is the last bi-monthly blog post for KDE PIM. We will continue to work on KDE PIM but weekly improvements to KDE PIM are now included in the This Week in KDE Apps blog.

Akademy

The KDE PIM team was at Akademy from the 7th to the 12th of September in Würzburg (Germany). We hosted again a PIM BoF.

We covered a few topics and made plans. In particular we touched upon contributions blockers, we hope the milestone system will help and also working on the amount of repositories which are not part of KDE Frameworks. Things are progressing in the right direction but slowly. Feel free to reach out to help!

Milestones

Talking about the milestones. You can see what we got in store on the Gitlab board. Some of them are progressing nicely like the resurrection of Kontact for Windows or the port away from QCA.

If you see anything you fancy and you would like to help, reach out to us on the #kontact:kde.org Matrix channel!

Applications Itinerary

Our travel assistance app Itinerary got a new two-level trip/timeline view, an extended public transport location search, a new full trip map view and better Android platform integration. Read more in [its own bi-monthly update] (https://volkerkrause.eu/2024/10/03/kde-itinerary-august-september-2024.html).

KAlarm

David has been working on fixing bugs around sound handling. In particular, repeating audio alarms only playing once have been fixed. Likewise the failure to play sound files using libVLC on some systems is gone. Also the backend to play sound can be changed at build time, it can use VLC or MPV.

But that's not the only bugs which got squashed. It's now possible to wake from suspend when using RTC wake and a crash has been fixed affecting systems where the kernel supports alarm timers.

Last but not least, the GUI has been improved around the run mode options in the preferences dialog.

Merkuro

Claudio has been busy fixing regressions and improving the stability of Merkuro. Notably, maps are now displayed again (if the event contains coordinates). Also, the collection combobox in the editors are now initialized with a valid collection and filtering features have been repaired.

KAddressBook and KOrganizer

The general improvements to support Plasma Activities is still on going. It is not enabled by default as it requires Akonadi Resources support to become really useful and the corresponding changes are not there yet.

KMail

On the KMail front the search has been greatly improved. There is now a custom syntax usable in the search text field. One can now use keywords like subject:, body:, to, from, has:attachment, is:important, is:replied and so on to make more precise queries.

For instance one could write "from:vkrause@kde.org to:kde-pim@kde.org is:important" to get only the emails from Volker on the kde-pim mailing list which are also flagged as important.

As you may know, Fedora KDE 41 was released a couple of weeks ago.

I wanted to talk about a special feature that our colleague @farchord (with support from upstream developer @Nate Graham) has brought to our Fedora KDE distribution:

Enabling Third Party Repositories With A Single Click!

Thanks to the flexibility of plasma-welcome we can offer this feature

Right after installing Fedora and on first login you will be presented with the Plasma Welcome window:

Before you click on Skip , you can go through the different slides to read about KDE and Fedora and also to decide whether you want to contribute with anonymous metrics or not (note: I personally do not):

Here is where the interesting part comes in, on the next slide:

With a simple click of a button you will enable the most commonly requested by our users Third Party Repositories like rpmfusion! (note: you will be asked for your administrator password)

Once the request is processed, the message will change to:

That’s it! You have successfully enabled Third Party Repositories without needing to modify any file or running any command whatsoever

Before you do anything with your system and your new configuration, I will strongly recommend to update your system via Plasma Discover :

Proceed with all the update and reboot to get the latest and shiniest from our repositories.

Finally, to verify that the Third Party software is available, you can check:

And that is it!

Enjoy!

This is all thanks to farchord, siosm , aleasto and ngraham‘s work!

Has this ever occurred to you? The most joyful moments of your life got filled with sorrow, a grief of loss…

Let’s talk about the Ubuntu Summit first, my international conference and solo travel outside my country. Probably I am the first from my entire extended family to visit a European country. My parents, well-wishers everyone was so happy. Only person didn’t know much about this, my maternal grandfather, whom I called (yes, “called”, he left us on 27th October 2024) Dada. Let me tell you about the summit first.

This week was full of major feature work and UI polishing, in addition to a lot of bug-fixing! I'm pretty sure everyone will find something to be excited about here:

Notable New Features

You can now swap the functions of drawing tablet pen buttons if you like the function performed by one of the buttons, but not which button activates it. (Joshua Goins, 6.3.0. Link)

Info Center now shows all of your GPUs, not just one of them. And they are now indicated in a fancy way! (Harald Sitter, 6.3.0. Link 1 and link 2)

Discover now shows you when apps are either packaged directly by their developer, or verified by a trusted third party. (Aleix Pol Gonzalez, 6.3.0. Link)

The Printers widget now shows each printer's print queue inline, right there in the widget! (Kai Uwe Broulik, 6.3.0. Link)

The Task Manager widget now lets you configure whether the "I'm playing audio" icons that appear in the corner of tasks can be clicked to mute the audio. In addition, the audio controls now always appear in the window preview thumbnails, and can't be accidentally disabled. (Petar Margetic, 6.3.0. Link)

When you've set up your system to reboot into the bootloader menu the next time it reboots (and not the firmware screen; that case was already handled), the logout screen how indicates this. (Nikolay Kochulin, 6.3.0. Link)

Notable UI Improvements

When you put a pie chart style System Monitor widget on a really skinny panel, the percentage circle in the center now looks nice, rather than being jagged and overly bold. (Arjen Hiemstra, 6.2.4. Link)

Made the progress indicators on Discover's Updates page more readable. (Nate Graham, 6.2.4. Link)

The Keyboard Indicator widget now indicates when modifier keys are "latched" or "locked", as they can be when using certain accessibility settings. (Nicolas Fella, 6.3.0. Link)

Removed the "Settings" launcher menu category! Now all of its contents have been moved into the "System" category. This reduces the number of categories that don't offer meaningful grouping. (Nate Graham, 6.3.0. Link)

The Printers widget now shows a little busy spinner for any printers that are currently printing, to make them easier to pick out among others when there are a lot of printers available. (Kai Uwe Broulik. 6.3.0. Link)

Widgets placed on the desktop are now very slightly translucent, just like the popups of widgets placed on the panel. (Marco Martin, 6.3.0. Link)

When for some reason the system time zone is set incorrectly or not set at all, the Digital Clock widget now tells you what's going on and offers you the chance to fix it yourself instead of just being broken. (Niccolò Venerandi, 6.3.0. Link)

Added a distinct Breeze icon for System Settings' Shortcuts page. (Joshua Goins, Frameworks 6.9. Link)

Improved the Breeze icon shown on password dialogs. (Kai Uwe Broulik, Frameworks 6.9. Link)

Notable Bug Fixes

Fixed a case where KWin would crash when plugging in external screens. (Xaver Hugl, 6.2.3. Link)

Fixed a regression caused by a version 0.22 of the power-profiles-daemon service that caused power profiles to not be registered properly by Plasma's Power and Battery widget until you manually restarted the Powerdevil service. (Méven Car, 6.2.3. Link)

Discover's auto-update feature once again works for Flatpak apps. (Harald Sitter, 6.2.4. Link)

The speaker test window on System Settings' Audio page now always fits its content, no matter what the name of the device or its audio profile may be. (Ismael Asensio, 6.2.4. Link)

Fixed a strange issue that would make GTK 4 apps look too dark when using HDR mode. Now they're a bit too light, but this is a GTK 4 bug. (Xaver Hugl, 6.2.4. Link)

Plasma panels in "fit content" mode are now compatible with flexible spacers; placing one on a panel no longer causes it to slowly grow to its full width when Plasma starts up — which was hilarious, but wrong. (Niccolò Venerandi, 6.2.4. Link)

Fixed a small visual glitch in KWin's Overview effect that caused windows dragged-and-dropped onto the desktop bar to strangely glide off screen. (Marco Martin, 6.2.4. Link)

Did a major code refactor and bug-fixing spree for desktop icon positioning, which fixes almost all of the outstanding bug reports about icons moving around, and also adds autotests to validate the fixes! You can read more about it here, too. (Akseli Lahtinen, 6.3.0. Link)

Alt key accelerators for items in the Global Menu widget now work on Wayland. (Nicolas Fella, 6.3.0. Link)

Performing a major system update using Discover no longer makes a pointless and invisible authentication prompt appear behind the logout window when you try to reboot to complete the update. (Alessandro Astone, PackageKit 1.3.1. Link)

Other bug information of note:

• 4 Very high priority Plasma bug (same as last week). Current list of bugs
• 37 15-minute Plasma bugs (down from 40 last week). Current list of bugs
• 106 KDE bugs of all kinds fixed over the last week. Full list of bugs

Notable in Performance & Technical

The feature to let you record the screen without re-approval if it's the same as one you did last time now also works when using rectangular region recordings. (David Redondo, 6.3.0. Link)

Implemented support for the Wayland system bell protocol. (David Redondo, 6.3.0. Link)

How You Can Help

KDE has become important in the world, and your time and contributions have helped us get there. As we grow, we need your support to keep KDE sustainable.

You can help KDE by becoming an active community member and getting involved somehow. Each contributor makes a huge difference in KDE — you are not a number or a cog in a machine!

You don’t have to be a programmer, either. Many other opportunities exist:

• Filter and confirm bug reports, maybe even identify their root cause
• Contribute designs for wallpapers, icons, and app interfaces
• Design and maintain websites
• Translate user interface text items into your own language
• Promote KDE in your local community
• …And a ton more things!

You can also help us by donating to our yearly fundraiser! Any monetary contribution — however small — will help us cover operational costs, salaries, travel expenses for contributors, and in general just keep KDE bringing Free Software to the world.

To get a new Plasma feature or a bugfix mentioned here, feel free to push a commit to the relevant merge request on invent.kde.org.

In this week's Beyond Blocks podcast episode, I spoke to Jess Archer - Engineering Team Lead at Laravel.

We discuss Laravel Prompts which was released at Laracon US last year and added to Drush 13, but also about PHP, Laravel, Neovim, working in the terminal and bullet journaling.

Listen to the episode now.

A few weeks ago Qt 6.8 was released, delivering many fixes and improvements for our software. Some of them were contributed by yours truly, and in this post I want to highlight some of them.

They relate to graphics tablet/stylus input on Wayland. Before we go into the fixes let’s have a quick overview of the flow of tablet input events on Wayland:

The genesis of input events is in the kernel driver for the particular tablet, which talks to the hardware (via USB, bluetooth etc). The kernel passes events to userspace via the evdev system. On the userspace side a Wayland compositor reads those events. Most compositors leverage libinput for this, a library that transforms raw evdev events into something more usable for the compositor while applying some cleaning and configuration. The compositor then delivers events to native Wayland applications using the tablet-v2 protocol. For legacy XWayland applications the compositor uses this protocol to send events to XWayland, which translates them into things X11 apps understand. The compositor can apply useful transformations to the input, like which area of the screen the tablet is mapped to, changing the pressure curve of the pen, or binding buttons to keyboard shortcuts.

The application then processes the events, potentially leveraging a UI toolkit like Qt. Qt creates QTabletEvent object for incoming Wayland events and delivers those to all UI elements. In case no UI element reacts to the event Qt will synthesize a mouse event from the tablet event and deliver that to the UI elements. That way most controls like buttons and menus don’t need special code to handle tablet input. Only when doing very low-level input handling or when needing tablet-specific interactions (like reacting to different pressure values) application developers need to explicitly handle tablet events in their code. Most UI toolkits will work somewhat similar to this. If an application doesn’t react to tablet input at all please file a bug against the application.

Qt Wayland had support for tablet input for a few years now, so what exactly needed fixing? The first thing is cursors. In Wayland the application tells the compositor which cursor to use. This can be done either by specifying a surface (i.e. an image) or a named cursor shape. Guess which one Qt used? That’s right: Neither. It just didn’t specify a cursor at all. The result depends on the compositor: KWin would display a cross-hair cursor as a fallback, which is ~okay, but not the cursor the application developer asked for. On other compositors I’ve tested there will be no cursor visible at all, which isn’t okay at all. For Qt 6.8 I implemented the missing cursor support, so now tablets get the same cursor as mouse input (unless of course the application developer wants a different cursor for tablet input).

Another thing that affected mostly non-Plasma users is client-side decorated windows. On Plasma Qt applications usually use the server-side decoration provided by KWin, but e.g. on GNOME Qt is responsible for drawing and handling window decorations. For this Qt features a plugin system so different decorations with different look-and-feels can be swapped out. Unfortunately those decorations didn’t handle tablet input at all, so it wasn’t possible to move around or close windows using a tablet stylus. I fixed this by pretending the tablet input is mouse input to the decorations, which was a simple yet effective solution for the issue. If there is ever a need for decorations to treat tablet input different to mouse input we can revisit this.

Talking about moving windows, a feature most KDE apps have (even if off-by-default these days) is dragging any empty area to move the window. This wasn’t working when using a stylus. Why? For that we need to look at how this works on a Wayland level. The xdg-shell protocol (the one responsible for most application windows) has a move request that asks the compositor to start a move interaction for the window. As part of the request the application must pass a serial, which is a number that corresponds to the last input event the application has received. To avoid applications suddenly deciding to move in the background compositors usually only allow move requests as a result of direct user input, so this serial must match the last input event. Qt wraps this move request inside the QWindow::startSystemMove function. The problem was that Qt didn’t keep track of the serial it received as part of tablet input, so when starting the move it would pass a wrong serial and the compositor (rightfully) refused the move. A few extra lines later the serial was tracked properly and moving windows with a stylus worked, just in time for Nate to disable the feature by default.

The same problem also affected drag-and-drop. When starting a drag with a stylus Qt now passes the correct serial, making drag-and-drop work (at least on the Qt side, there currently is a bug on the KWin side that prevents this from working).

The last fix for today relates to how applications react to the tablet events. Sometimes applications process clicks differently depending on what keyboard modifiers are pressed. For example pressing Ctrl while clicking on files in Dolphin allows to select multiple files. For this to work Qt conveniently delivers the active modifiers with every input event. Alas for tablet input the modifiers got lost along the way, so it wasn’t possible to select multiple files using a stylus. One small fix later it works as expected.

That’s all the Wayland tablet related fixes for today. If you find more issues in Qt/KDE apps related to tablet input on Wayland please report them on bugs.kde.org and I’ll look into them.

That’s not all there is about Wayland tablet improvements though. Fully in the spirit of the “We care about your input!” Goal there are exiting things happening on the KWin/Plasma side that I’ve been involved in. Stay tuned for more!

In my position of Software Platform Engineer at KDE I work on common building blocks for KDE software, like Qt and KDE Frameworks. This work is possible thanks to your generous donations. Check out our end-of-the-year fundraiser if you’d like to see more work like this.

Just in time for the winter holidays, the GNU Press shop is open!

Just in time for the winter holidays, the GNU Press shop is open!

Make sure you commit anything you want to end up in the KDE Gear 24.12
releases to them

Next Dates:

•   November 14, 2024: 24.12 freeze and beta (24.11.80) tagging and release
•   November 28, 2024: 24.12 RC (24.11.90) tagging and release
•   December  5, 2024: 24.12 tagging
•   December 12, 2024: 24.12 release

https://community.kde.org/Schedules/KDE_Gear_24.12_Schedule

I created a dashboard for testing multiple URLs at the same time using Axe.

Let’s go for my web review for the week 2024-45.

Voted in America? This Site Doxed You

Tags: tech, democracy

I didn’t know the voting rolls were public record in the US… this is a really bad idea.

https://www.404media.co/voted-in-america-this-site-doxed-you/

One weird trick to get the whole planet to send abuse complaints to your best friend(s)

Tags: tech, networking, security, protocols

Looks like there are people out there to get Tor relays down… and they found a smart networking trick I’d expect to not work anymore.

https://delroth.net/posts/spoofed-mass-scan-abuse/

XMPP: the forgotten gem of Instant Messaging

Tags: tech, xmpp, ux

Could XMPP make a come back if the user experience was better?

https://adele.pages.casa/md/blog/xmpp-the-forgotten-gem-of-instant-messaging.md

A conceptual model of ATProto and ActivityPub

Tags: tech, protocols, fediverse, governance, decentralized

Interesting explanation of the different visions and governance behind ActivityPub and ATProto.

https://fediversereport.com/a-conceptual-model-of-atproto-and-activitypub/

A Map of Sync

Tags: tech, syncing, data

Interesting dimensions to use when classifying syncing solutions and to see which ones will meet your constraints.

https://stack.convex.dev/a-map-of-sync

DuckDB over Pandas/Polars

Tags: tech, databases, data-science

A good reminder that I should probably evaluate DuckDB for some of my tooling.

https://pgrs.net/2024/11/01/duckdb-over-pandas-polars/

Why systemd is a problem for embedded Linux

Tags: tech, systemd, embedded

This is a good point. systemd is kind of turning into a monoculture, but what are we loosing? Indeed, right now things could be better on deeply embedded systems (I insist on the “deep embedded” here which is often more limited in resources). Unlike the author I think they could be improved and they don’t quite apply to a good chunk of recent embedded platforms though.

https://kevinboone.me/systemd_embedded.html

How the New sqlite3_rsync Utility Works

Tags: tech, databases, sqlite, tools, syncing

If you wonder how the protocol is designed and how the actual implementation works, this is a nice introduction. Clearly it’s helped by the size of that program which is fairly small.

https://nochlin.com/blog/how-the-new-sqlite3_rsync-utility-works

C++, Complexity, and Compiler Bugs

Tags: tech, c++, complexity

Good illustration of how the C++ language complexity is out of hands.

https://azeemba.com/posts/cpp-complexity-compiler-bugs.html

Having fun with modern C++ – Daniel Lemire’s blog

Tags: tech, c++

Still, C++ improved in recent years. The problem is that we tend to stick too much to the old constructs we already know and that things keep piling up but nothing is removed.

https://lemire.me/blog/2024/11/02/having-fun-with-modern-c/

smolweb HTML specification

Tags: tech, html, accessibility, low-tech, complexity

A nice subset of HTML to ensure better accessibility and reduced complexity.

https://smolweb.org/specs/index.html

HTML link, or button, that is the question

Tags: tech, web, frontend, html

Each has a use, they shouldn’t be conflated. It makes for poor user experience and accessibility otherwise.

https://marijkeluttekes.dev/blog/articles/2024/11/04/html-link-or-button-that-is-the-question/

Long Distance Relationships

Tags: tech, remote-working, management, product-management

A bit biased toward stable product teams only. Still, there are good tips which are more widely applicable here. This gives a good idea of the management of a distributed team of remote workers.

https://matt.blwt.io/post/long-distance-relationships/

Bye for now!

The topic of this posting already tells you that an old Unix guy tells stories about old techniques.

I'm a happy NIS (formerly YP) user since 30+ years. I started using it with SunOS 4.0, later using it with Solaris and with Linux since 1999.

In the past, a colleague wasn't happyly using NIS+ when he couldn't log in as root after a short time because of some well known bugs and wrong configs. NIS+ was also much slower than my NIS setup. I know organisations using NIS for more than 80.000 user accounts in 2024.

I know the security implications of NIS but I can live with them, because I manage all computers in the network that have access to the NIS maps. And NIS on Linux offers to use shadow maps, which are only accessible to the root account. My users are forced to use very long passwords.

Unfortunately NIS support for the PAM modules was removed in Debian in pam 1.4.0-13, which means Debian 12 (bookworm) is lacking NIS support in PAM, but otherwise it is still supported. This only affects changing the NIS password via passwd. You can still authenticate users and use other NIS maps.

But yppasswd is deprecated and you should not use it! If you use yppasswd it may generate a new password hash by using the old DES crypt algorithm, which is very weak and only uses the first 8 chars in your password. Do not use yppasswd any more! yppasswd only detects DES, MD5, SHA256 and SHA512 hashes, but for me and some colleagues it only creates weak DES hashes after a password change. yescrypt hashes which are the default in Debian 12 are not supported at all. The solution is to use the plain passwd program.

On the NIS master, you should setup your NIS configuration to use /etc/shadow and /etc/passwd even if your other NIS maps are in /var/yp/src or similar. Make sure to have these lines in your /var/yp/Makefile:

PASSWD = /etc/passwd SHADOW = /etc/shadow

Call make once, and it will generate the shadow and passwd map. You may want to set the variable MINUID which defines which entries are not put into the NIS maps.

On all NIS clients you still need the entries (for passwd, shadow, group,...) that point to the nis service. E.g.:

passwd: files nis systemd group: files nis systemd shadow: files nis

You can remove all occurences of "nis" in your /etc/pam.d/common-password file.

Then you can use the plain passwd program to change your password on the NIS master. But this does not call make in /var/yp for updating the NIS shadow map.

Let's use inotify(7) for that. First, create a small shell script /usr/local/sbin/shadow-change:

#! /bin/sh PATH=/usr/sbin:/usr/bin # only watch the /etc/shadow file if [ "$2" != "shadow" ]; then exit 0 fi cd /var/yp || exit 3 sleep 2 make

Then install the package incron.

# apt install incron # echo root >> /etc/incron.allow # incrontab -e

Add this line:

/etc IN_MOVED_TO /usr/local/sbin/shadow-change $@ $# $%

It's not possible to use IN_MODIFY or watch other events on /etc/shadow directly, because the passwd command creates a /etc/nshadow file, deletes /etc/shadow and then moves nshadow to shadow. inotify on a file does not work after the file was removed.

You can see the logs from incrond by using:

# journalctl _COMM=incrond e.g. Oct 01 12:21:56 kueppers incrond[6588]: starting service (version 0.5.12, built on Jan 27 2023 23:08:49) Oct 01 13:43:55 kueppers incrond[6589]: table for user root created, loading Oct 01 13:45:42 kueppers incrond[6589]: PATH (/etc) FILE (shadow) EVENT (IN_MOVED_TO) Oct 01 13:45:42 kueppers incrond[6589]: (root) CMD ( /usr/local/sbin/shadow-change /etc shadow IN_MOVED_TO)

I've disabled the execution of yppasswd using dpkg-divert

# dpkg-divert --local --rename --divert /usr/bin/yppasswd-disable /usr/bin/yppasswd chmod a-rwx /usr/bin/yppasswd-disable

Do not forget to limit the access to the shadow.byname map in ypserv.conf and general access to NIS in ypserv.securenets.

I've also discovered the package pamtester, which is a nice package for testing your pam configs.

Have you wanted the flexibility of f-strings but need safety checks in place? What if you could have deferred evaluation for logging or avoiding injection attacks? Christopher Trudeau is back on the show this week, bringing another batch of PyCoder's Weekly articles and projects.

[ Improve Your Python With 🐍 Python Tricks 💌 – Get a short & sweet Python Trick delivered to your inbox every couple of days. >> Click here to learn more and see examples ]

DrupalCamp Berlin 2024 has officially started! More than 200 Drupal enthusiasts are gathering at the atmospheric Alte Münze in the heart of Berlin to explore the latest trends and share insights. Our CEO, Grzegorz Bartman, is representing Droptica there. To mark the occasion, we've teamed up with our developers to curate a handpicked list of seven sessions from the event program that are well worth attending during this two-day gathering.

What is this pattern about?

The Pipeline design pattern (also known as Chain of Command pattern) is a flexible way to handle a sequence of actions, where each handler in the chain processes the input data and passes it to the next handler. This pattern is commonly used in scenarios involving data processing, web scraping, or middleware systems.

In this blog post, I’ll walk you through a specific example that leverages Python’s powerful functools.reduce and partial functions, along with the BeautifulSoup library for parsing HTML content. This code showcases the Pipeline pattern applied to HTML table extraction and processing.

What Does the Code Do?

The code defines a pipeline of data parsing steps for extracting and cleaning tables from an HTML file. It follows a functional programming approach to compose several processing functions into a unified flow using the Chain of Command pattern.

Key Concepts

1. Functional Composition: Combining multiple functions into one that executes in a specific order.
2. Data Parsing Pipeline: Sequential processing of HTML content into structured data (a DataFrame).
3. Error Handling: Ensuring the pipeline gracefully handles missing or malformed data.

Let’s break down the code step by step:

1. Function Composition with composefrom functools import reduce, partial from typing import Callable

The pipeline is created by composing multiple parsing functions into a single unified function. The compose function uses reduce to chain these functions together:

def compose(*functions: ParsingPipeline) -> ParsingPipeline: """Composes functions into a single function""" return reduce(lambda f, g: lambda x: g(f(x)), functions, lambda x: x)

This allows you to define an ordered flow of operations that process input data from one function to the next. Each function modifies the input data, which is then passed down the pipeline.

2. Reading HTML Content

The first step in the pipeline is to read the contents of an HTML file. This is done by read_htm_from:

def read_htm_from(filename: T, mode: T = "r", encoding: T = "utf-8") -> T: with open(filename, mode, encoding=encoding) as file: html_content = file.read() return html_content

This function opens an HTML file and returns its content as a string. It supports different file modes and encodings, making it flexible for various file formats.

Note that T is defined here as TypeVar("T"), see the typing docs.

3. Parsing the HTML Table

Next, read_table_from uses BeautifulSoup to find the HTML table within the file:

from bs4 import BeautifulSoup def read_table_from(htm_file: T, parser: str = "html.parser") -> T: soup = BeautifulSoup(htm_file, parser) table = soup.find("table") return table

This function converts the HTML content into a BeautifulSoup object and extracts the first table it finds. The parsed table is passed down the pipeline for further processing.

4. Extracting Rows and Data

Once the table is identified, the pipeline extracts the rows and applies filtering logic based on custom markers:

def extract_row_data_from( table_rows: T, start_markers: T, continue_markers: T, end_markers: T ) -> T: row_data: T = [] start_processing = False for row in table_rows: if any(marker in row.text for marker in start_markers) and not start_processing: start_processing = True continue if start_processing: if any(marker in row.text for marker in continue_markers): continue if any(marker in row.text for marker in end_markers): break row_data.append(row) return row_data[:-1]

This function inspects each row in the table, checking if the row text matches specified start, continue, or end markers. Data extraction begins after encountering the start marker and ends when the end marker is found.

5. Converting Rows to DataFrame

The next steps involve transforming the extracted row data into a structured pandas DataFrame. First, the rows are separated into individual columns using separate_columns_in:

def separate_columns_in(rows: T) -> T: data_rows: T = [] try: for row in rows: columns = row.find_all(["td", "th"]) data = [col.text for col in columns] data_rows.append(data) return data_rows except Exception as e: print(f"An error occurred: {str(e)}") return []

Then, convert_to_dataframe reshapes this data into a pandas DataFrame:

def convert_to_dataframe(data_rows: T) -> T: df = pd.DataFrame(data_rows) df = df.rename(columns=df.iloc[0]).drop(df.index[0]) df.columns = COLUMN_NAMES df.drop(columns=COLUMNS_TO_REMOVE, axis=1, inplace=True) df.set_index(df.columns[0], inplace=True, drop=True) return df

The DataFrame is cleaned up by renaming columns, removing unnecessary columns, and setting the correct index.

6. Assigning Correct Data Types

Finally, assign_correct_data_type_to ensures that the DataFrame columns have the appropriate data types:

def assign_correct_data_type_to( df: T, dict_types: dict[str, str] = COLUMN_TYPES, datetime_columns: list[str] = DATETIME_COLUMN_NAMES, ) -> T: if not isinstance(df, pd.DataFrame): raise ValueError("Input `df` must be a pandas DataFrame.") df = df.copy() for column in datetime_columns: if column in df.columns: df[column] = pd.to_datetime(df[column]) for column, col_type in dict_types.items(): if column in df.columns: try: if col_type == "numeric": df[column] = pd.to_numeric(df[column], errors="coerce") else: df[column].astype(col_type) except Exception as e: print(f"Error converting column {column} to {col_type}: {e}") return df

This function converts columns into numeric or datetime formats as needed, ensuring that the data is properly structured for analysis.

7. Putting It All Together

At the end of the code, the pipeline is composed by chaining all of the above functions together:

parse_gbx_bt: ParsingPipeline = compose( partial(read_htm_from, mode="r", encoding="utf-8"), read_table_from, read_rows_from, partial( extract_row_data_from, start_markers=["Closed Transactions:"], continue_markers=["Genbox", "balance", "Deposit"], end_markers=["Closed P/L:"], ), separate_columns_in, convert_to_dataframe, assign_correct_data_type_to, )

This creates a fully automated pipeline that:

1. Reads an HTML file.
2. Extracts table data.
3. Cleans and converts the data into a pandas DataFrame.
4. Assigns the correct data types.

Conclusion

This implementation of the Chain of Command or Pipeline pattern in Python demonstrates how to apply functional programming principles to data parsing tasks. The use of functools.reduce and partial, and BeautifulSoup provides a flexible, reusable way to process HTML content and structure it into usable data.

If you’re looking to create complex data processing pipelines that need to handle dynamic data from HTML or other sources, this approach is a clean and maintainable solution.

You can find the code in the repo: https://github.com/jjeg1979/pyBacktestAnalyzer.

And if you want to watch the code clinic where I presented the tool, feel free to check it out at https://pybites.circle.so/c/circle-coaching-calls/python-for-the-trader-code-clinic.

If you cannot access…well, what are you waiting for to become a PDM member?

Exposing External and Custom Data to Views with hook_views_data() admin Fri, 11/08/2024 - 11:12

Debian Contributions: 2024-10

Contributing to Debian is part of Freexian’s mission. This article covers the latest achievements of Freexian and their collaborators. All of this is made possible by organizations subscribing to our Long Term Support contracts and consulting services.

rebootstrap, by Helmut Grohne

After significant changes earlier this year, the state of architecture cross bootstrap is normalizing again. More and more architectures manage to complete rebootstrap testing successfully again. Here are two examples of what kind of issues the bootstrap testing identifies.

At some point, libpng1.6 would fail to cross build on musl architectures whereas it would succeed on other ones failing to locate zlib. Adding --debug-find to the cmake invocation eventually revealed that it would fail to search in /usr/lib/<triplet>, which is the default library path. This turned out to be a bug in cmake assuming that all linux systems use glibc. libpng1.6 also gained a baseline violation for powerpc and ppc64 by enabling the use of AltiVec there.

The newt package would fail to cross build for many 32-bit architectures whereas it would succeed for armel and armhf due to -Wincompatible-pointer-types. It turns out that this flag was turned into -Werror and it was compiling with a warning earlier. The actual problem is a difference in signedness between wchar_t and FriBidChar (aka uint32_t) and actually affects native building on i386.

Miscellaneous contributions

• Helmut sent 35 patches for cross build failures.
• Stefano Rivera uploaded the Python 3.13.0 final release.
• Stefano continued to rebuild Python packages with C extensions using Python 3.13, to catch compatibility issues before the 3.13-add transition starts.
• Stefano uploaded new versions of a handful of Python packages, including: dh-python, objgraph, python-mitogen, python-truststore, and python-virtualenv.
• Stefano packaged a new release of mkdocs-macros-plugin, which required packaging a new Python package for Debian, python-super-collections (now in NEW review).
• Stefano helped the mini-DebConf Online Brazil get video infrastructure up and running for the event. Unfortunately, Debian’s online-DebConf setup has bitrotted over the last couple of years, and it eventually required new temporary Jitsi and Jibri instances.
• Colin Watson fixed a number of autopkgtest failures to get ansible back into testing.
• Colin fixed an ssh client failure in certain cases when using GSS-API key exchange, and added an integration test to ensure this doesn’t regress in future.
• Colin worked on the Python 3.13 transition, fixing problems related to it in 15 packages. This included upstream work in a number of packages (postgresfixture, python-asyncssh, python-wadllib).
• Colin upgraded 41 Python packages to new upstream versions.
• Carles improved po-debconf-manager: now it can create merge requests to Salsa automatically (created 17, new batch coming this month), imported almost all the packages with debconf translation templates whose VCS is Salsa (currently 449 imported), added statistics per package and language, improved command line interface options. Performed user support fixing different issues. Also prepared an abstract for the talk at MiniDebConf Toulouse.
• Santiago Ruano Rincón continued the organization work for the DebConf 25 conference, to be held in Brest, France. Part of the work relates to the initial edits of the sponsoring brochure. Thanks to Benjamin Somers who finalized the French and English versions.
• Raphaël forwarded a couple of zim and hamster bugs to the upstream developers, and tried to diagnose a delayed startup of gdm on his laptop (cf #1085633).
• On behalf of the Debian Publicity Team, Anupa interviewed 7 women from the Debian community, old and new contributors. The interview was published in Bits from Debian.

The diffoscope maintainers are pleased to announce the release of diffoscope version 283. This version includes the following changes:

[ Martin Abente Lahaye ] * Fix crash when objdump is missing when checking .EFI files.

You find out more by visiting the project homepage.

I wrote in the past about how I'm a pessimist that strives for positive outcomes. One of the things that I gradually learned is is wishing others to succeed. That is something that took me a long time to learn. I did not see the value in positive towards other people's success, but there is. There is one thing to be sceptical to a project or initiative, but you can still encourage the other person and wish them well.

I think not wishing others well is a coping mechanism of sorts. For sure it was for me. As you become more successful in life, it becomes easier to be supportive, because you have established yourself in one way or another and you feel more secure about yourself.

That said, there is something I continue to struggle with, and that are morals. What if the thing the other person is doing seems morally wrong to me? I believe that much of this struggle stems from the fear of feeling complicit in another's choices. Supporting someone — even passively — can feel like tacit approval, and that can be unsettling. Perhaps encouragement doesn't need to imply agreement. Another angle to consider is that my discomfort may actually stem from my own insecurities and doubts. When someone's path contradicts my values, it can make me question my own choices. This reaction often makes it hard to wish them well, even when deep down I want to.

What if my tribe is just wrong on something? I grew up with the idea of “never again”. Anything that remotely looks like fascism really triggers me. There is a well known propaganda film from the US Army called “Don't Be a Sucker” which warns Americans about the dangers of prejudice, discrimination, and fascist rhetoric. I watched this a few times over the years and it still makes me wonder how people can fall for that kind of rhetoric.

But is it really all that hard? Isn't that happening today again? I have a very hard time supporting what Trump or Musk are standing for or people that align with them. Trump's rhetoric and plans are counter to everything I stand for and the remind me a lot of that film. It's even harder for me with Musk. His morals are completely off, he seems to a person I would not want to be friends with, yet he's successful and he's pushing humanity forward.

It's challenging to reconcile my strong opposition to their (and other's) rhetoric and policies with the need to maintain a nuanced view of them. Neither are “literal Hitler”. Equating them with the most extreme historical figures oversimplifies the situation and shuts down productive conversation.

Particularly watching comedy shows reducing Trump to a caricature feels wrong to me. Plenty of his supporters have genuine concerns. I find it very hard to engage with these complexities and it's deeply uncomfortable and quite frankly exhausting.

Life becomes simpler when you just pick a side, but it will strip away the deeper understanding and nuance I want to hold onto. I don’t want to fall into the trap of justifying or defending behaviors I fundamentally disagree with, nor do I want to completely shut out the perspectives of those who support him. This means accepting that people I engage with, might see things very differently, and that maintaining those relationships and wishing them well them requires a level of tolerance I'm not sure I possess yet.

The reason it's particularly hard to me that even if I accept that my tribe maybe wrong in parts, I can see the effects that Trump and others already had on individuals. Think of the Muslim travel ban which kept families apart for years, his border family separation policy, the attempted repeal of Section 230. Some of it was not him, but people he aligned with. Things like the overturning of Roe v. Wade and the effects it had on women, the book bans in Florida, etc. Yes, not quite Hitler, but still deeply problematic for personal freedoms. So I can't ignore the harm that some of these policies have caused in the past and even if I take the most favorable view of him, I have that track record to hold against him.

In the end where does that leave me? Listening, understanding, and standing firm in my values. But not kissing the ring. And probably coping by writing more.