Blog posts in English on jkossen.nl

A few examples of and notes on Podman quadlets

Jochem Kossen — Thu, 26 Feb 2026 00:00:00 +0000

WARNING: this post is incomplete, i published it because someone needed its content. I’ll rework it soonish.

Enable automatic updates

1systemctl --user enable podman-auto-update.service
2systemctl --user enable podman-auto-update.timer

rproxy.container

Put this file, and the other quadlets (rproxy-data.volume, podman-ipv6.network, …), in .config/containers/systemd/ within the home dir of the user which runs the container.

This will create the rproxy systemd service automatically. If not, test your configuration with:

1/usr/libexec/podman/quadlet --dryrun --user

Enable the service with:

1systemctl --user enable rproxy

contents of rproxy.container

 1[Container]
 2Image=docker.io/caddy:latest
 3PublishPort=[::]:10080:80
 4PublishPort=[::]:10443:443
 5Volume=/containers/rproxy/Caddyfile:/etc/caddy/Caddyfile
 6Volume=/containers/rproxy/security-headers.conf:/etc/caddy/security-headers.conf
 7Volume=rproxy-data.volume:/data
 8Network=podman-ipv6.network
 9AutoUpdate=registry
10
11[Install]
12WantedBy=default.target

rproxy-data.volume

1[Volume]

podman-ipv6.network

1[Network]
2Driver=bridge
3IPv6=true
4Subnet=10.85.1.0/24
5Gateway=10.85.1.1
6Subnet=fd41:22a1:adca:2142::/64
7Gateway=fd41:22a1:adca:2142::1
8IPAMDriver=host-local
9DisableDNS=true

Simply Vim

Jochem Kossen — Sat, 13 Sep 2025 00:00:00 +0000

In search of a calm editor with few distractions, I made a configuration for the Vim text editor. While some don’t consider Vim to be an editor with low cognitive load, I humbly disagree with this. Yes it has a learning curve, but it’s well documented, and you can learn basic functionality very quickly. Also, the basic use of Vim does not change much, so everything you learn is knowledge you’ll be able to use for decades.

Note: there’s also nvi which is even lighter than vim. Unfortunately that doesn’t provide UTF-8 support, which makes it unsuitable for some of my writing.

You can get the configuration (.vimrc) at #code

Features

No syntax highlighting by default
No package management, so no automatic updates and breakage. Just download the plugins you use and put them in `~/.vim`
Most settings from vim-sensible by Tim Pope, but without the plugin
Toggle light / dark background
Clear the search highlight
For a nice writing environment, I use the *Goyo* and *Limelight* plugins
Insert a timestamp easily
All the power the Vim editor offers!

Keyboard shortcuts

Use these in 'normal' mode. Press SPACE before each key.

Key	Action
c	Clear search highlight
d	Toggle dark / light background
s	Toggle syntax highlighting
t	Insert timestamp
G	Toggle the Goyo plugin (center your text)
L	Toggle the Limelight plugin (highlight current paragraph, darken others)

A few tips on using Vim

Vim offers a lot of shortcuts for functionality to help you edit conveniently and fast. But you don’t need to remember them all. I don’t. Here are a few I do use regularly and which seem to stick in my mind.

Key	Action
{	Move cursor to before current paragraph
}	Move cursor to after current paragraph
/Fore	Move cursor to next occurrence of 'Fore'
?Back	Move cursor to previous occurrence of 'Back'
n	Move cursor to next match of previous search term
gg	Move cursor to beginning of file
G	Move cursor to end of file
:42	Move cursor to line 42
y4l	Yank (copy) the next 4 characters starting from the cursor
y4y	Yank (copy) 4 lines starting from the cursor
p	Paste yanked contents after current line
P	Paste yanked contents before current line
ciw	Replace word (think Change In Word)
ci(	Change next text between ()
ci<	Change next text between < and > (think HTML tags)
.	Repeat last modification action

Screenshots

Below are some screenshots of how this configuration of Vim looks. Click on them to see a larger version. I mostly have Limelight and syntax disabled, and use Vim full screen. So my screen usually looks like something resembling the first screenshot.

Vim and Goyo

Vim, Goyo and LimeLight

Vim, Goyo, LimeLight and syntax highlighting

Code

Save this file as $HOME/.vimrc and customize it to your heart’s desire :-)

 1" vi compatibility
 2set nocompatible
 3
 4" locale
 5language en_US.UTF-8
 6
 7" Encoding
 8set encoding=utf-8
 9
10" true color support
11set termguicolors
12
13" Color scheme (terminal)
14set t_Co=256
15
16" Syntax highlighting
17syntax off
18
19" Blink cursor on error instead of beeping (grr)
20set visualbell
21
22" How many lines of command history to remember?
23set history=1000
24
25" Show status line
26set laststatus=2
27
28" Show menu for completion
29set wildmenu
30
31" Show cursor position
32set ruler
33
34" Reread file changed outside vim
35set autoread
36
37" Delete comment character when joining commented lines
38set formatoptions+=j
39
40" Wrapping
41set wrap
42" Wrap at word boundary
43set lbr
44
45" Whitespace
46set textwidth=0
47set formatoptions=tcqrn1
48set tabstop=8
49set shiftwidth=8
50set softtabstop=8
51set noexpandtab
52set noshiftround
53set smarttab
54
55" How to indicate whitespace
56set listchars=tab:⟶\ ,trail:▸,extends:⟶,precedes:⟵,nbsp:+
57
58" Incremental search
59set incsearch
60
61" Highlight search
62set hlsearch
63
64" For plugins to load correctly
65filetype plugin indent on
66
67" limelight
68let g:limelight_conceal_ctermfg = 'gray'
69let g:limelight_conceal_ctermfg = 240
70
71" Use space for keyboard shortcuts
72nnoremap <SPACE> <Nop>
73let mapleader=" "
74
75" toggle syntax on/off
76nnoremap <expr> <Leader>s exists("syntax_on") ? ':syntax off<CR>' : ':syntax on<CR>'
77
78" toggle background light/dark
79nnoremap <expr> <Leader>d &background == 'light' ? ':set background=dark<CR>' : ':set background=light<CR>'
80
81" toggle listing of whitespace
82nnoremap <expr> <Leader>w ':set list!<CR>'
83
84" clear search highlight
85nnoremap <expr> <Leader>c ':noh<CR>'
86
87" insert timestamp
88map <Leader>t :put =strftime('%Y-%m-%d %a, %H:%M')<CR>
89
90" toggle Goyo
91nnoremap <expr> <Leader>G ':Goyo<CR>'
92
93" toggle Limelight
94nnoremap <expr> <Leader>L ':Limelight!!<CR>'

A simple JavaScript Lightbox without dependencies

Jochem Kossen — Mon, 19 Feb 2024 00:00:00 +0000

TLDR

photo.js: a simple zero-dependencies JavaScript image lightbox.

Abstract

Recently I got back into photography and wanted to show my photos on this website. So I searched the web for a script which would show large versions of the photos on a dark overlay without leaving the page. It should be easy to integrate into websites and pages should still be visible when the user has no JavaScript enabled. And as a rule, I also like smallish pieces of code. Most scripts that I found online consisted of many lines of code, probably because they were developed in a time when browser engines were far less compliant than those of today. Some also required multiple dependencies. And then there were those that lacked a feature I wanted to support: having multiple galleries on a single page.

Given all the possibilities web browsers nowadays give us I didn’t think it would be that hard coding this myself without using dependencies.

W3Schools (♥ you) has a nice little tutorial on how to get to the basics of a Lightbox done.

Starting from that I built a simple image gallery script that I use on this website.

You can see it in action in my IJssel Highwater 2024 and Litterland galleries.

Features

No dependencies on external libraries
Multiple galleries on a single page
Keyboard navigation:
- Left arrow moves back
- Right arrow moves forward
- ESC or x closes the lightbox
Disabling JavaScript should not break the website
Themeable using CSS

The Code

This is the version from the time of writing this article. It currently consists of 200-ish lines of code, that’s including JSDoc comments.

The JavaScript code consists essentially of two factory functions. One for the gallery to find the images, the other for the lightbox to show the large versions of the image.

Then there’s a main() function which loads everything.

It searches for HTML elements with the class gallery. For each such element, it searches <figure> elements with an image link in it. The lightbox will show the href of the <a href="...">. So when JavaScript is disabled, the links will still work.

Download the JavaScript code here: photo.js

JavaScript

  1/**
  2 * Photo gallery in JavaScript
  3 *
  4 * Copyright 2024 Jochem Kossen
  5 *
  6 * Permission is hereby granted, free of charge, to any person obtaining a
  7 * copy ofthis software and associated documentation files (the “Software”),
  8 * to deal in the Software without restriction, including without limitation
  9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 10 * and/or sell copies of the Software, and to permit persons to whom the
 11 * Software is furnished to do so, subject to the following conditions:
 12 *
 13 * The above copyright notice and this permission notice shall be included
 14 * in all copies or substantial portions of the Software.
 15 *
 16 * THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS
 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 22 * IN THE SOFTWARE.
 23 *
 24 */
 25
 26/**
 27 * Main script loop
 28 */
 29const main = function () {
 30  const galleries = document.getElementsByClassName("gallery");
 31
 32  for (let i = 0; i < galleries.length; i++) {
 33    const gallery = galleries[i];
 34    const lightbox = createLightbox();
 35    if (gallery instanceof HTMLElement) {
 36      createGallery(gallery, lightbox);
 37    }
 38  }
 39};
 40
 41/**
 42 * Create a Lightbox instance
 43 *
 44 * @returns {object}
 45 */
 46const createLightbox = function () {
 47  const lightbox = document.createElement("div");
 48  const lightboxContent = document.createElement("div");
 49  const img = document.createElement("img");
 50  const closeLink = document.createElement("a");
 51  const prevLink = document.createElement("a");
 52  const nextLink = document.createElement("a");
 53
 54  /** @type {function} */
 55  let onPrev;
 56
 57  /** @type {function} */
 58  let onNext;
 59
 60  closeLink.href = "#";
 61  closeLink.innerHTML = "&times;";
 62
 63  prevLink.href = "#";
 64  prevLink.innerHTML = "&#10094;";
 65
 66  nextLink.href = "#";
 67  nextLink.innerHTML = "&#10095;";
 68
 69  lightbox.id = "lightbox";
 70  lightbox.className = "lightbox";
 71
 72  lightbox.appendChild(closeLink);
 73  lightboxContent.appendChild(prevLink);
 74  lightboxContent.appendChild(img);
 75  lightboxContent.appendChild(nextLink);
 76  lightbox.appendChild(lightboxContent);
 77
 78  /**
 79   * @param {function} fn
 80   */
 81  const setOnPrev = (fn) => (onPrev = fn);
 82
 83  /**
 84   * @param {function} fn
 85   */
 86  const setOnNext = (fn) => (onNext = fn);
 87
 88  /**
 89   * @param {string} uri
 90   */
 91  const show = function (uri) {
 92    setImage(uri);
 93    lightbox.style.display = "block";
 94  };
 95
 96  const hide = function () {
 97    lightbox.style.display = "none";
 98  };
 99
100  /**
101   * @param {string} uri
102   */
103  const setImage = function (uri) {
104    img.src = uri;
105  };
106
107  /**
108   * Make the buttons in the lightbox work
109   */
110  const enableLightboxButtons = function () {
111    closeLink.addEventListener("click", (event) => {
112      event.preventDefault();
113      hide();
114    });
115
116    prevLink.addEventListener("click", (event) => {
117      event.preventDefault();
118      onPrev && onPrev();
119    });
120
121    nextLink.addEventListener("click", (event) => {
122      event.preventDefault();
123      onNext && onNext();
124    });
125
126    window.addEventListener("keydown", (event) => {
127      if (lightbox.style.display !== "block") {
128        return;
129      }
130
131      switch (event.key) {
132        case "ArrowLeft":
133          onPrev && onPrev();
134          break;
135        case "ArrowRight":
136          onNext && onNext();
137          break;
138        case "Escape":
139        case "x":
140          hide();
141          break;
142      }
143    });
144  };
145
146  enableLightboxButtons();
147  document.body.appendChild(lightbox);
148
149  return { show, setOnPrev, setOnNext };
150};
151
152/**
153 * Create a Gallery instance
154 *
155 * @param {HTMLElement} element
156 * @param {object} lightbox
157 */
158const createGallery = function (element, lightbox) {
159  /** @type {Array.<HTMLElement>} */
160  const slides = [];
161
162  /** @type {number} */
163  let prevSlide = 0;
164
165  /** @type {number} */
166  let nextSlide = 1;
167
168  const showLightboxOnClick = function(thumbnail, nr) {
169    thumbnail.firstElementChild?.addEventListener("click", (event) => {
170      event.preventDefault();
171      showLightbox(nr);
172    });
173  }
174    
175  const findSlides = function () {
176    const thumbnails = element.getElementsByTagName("figure");
177    for (let i = 0; i < thumbnails.length; i++) {
178      showLightboxOnClick(thumbnails[i], i);
179      slides.push(thumbnails[i]);
180    }
181  };
182
183  /**
184   * @param {number} slideNr
185   */
186  const showLightbox = function (slideNr) {
187    prevSlide = slideNr <= 0 ? slides.length - 1 : slideNr - 1;
188    nextSlide = slideNr >= slides.length - 1 ? 0 : slideNr + 1;
189
190    const link = slides[slideNr].firstElementChild;
191
192    if (link instanceof HTMLAnchorElement) {
193      lightbox.show(link.href);
194    }
195  };
196
197  findSlides();
198
199  lightbox.setOnPrev(() => showLightbox(prevSlide));
200  lightbox.setOnNext(() => showLightbox(nextSlide));
201};
202
203/**
204 * Start up the galleries
205 */
206main();

HTML

 1<div class="gallery">
 2  <figure>
 3    <a href="jpg-1280/DSCF8660-1280.jpg">
 4      <img src="jpg-500/DSCF8660-500.jpg" alt="IJssel" />
 5    </a>
 6  </figure>
 7
 8  <figure>
 9    <a href="jpg-1280/DSCF8663-1280.jpg">
10      <img src="jpg-500/DSCF8663-500.jpg" alt="IJssel" />
11    </a>
12  </figure>
13
14  <figure>
15    <a href="jpg-1280/DSCF8672-1280.jpg">
16      <img src="jpg-500/DSCF8672-500.jpg" alt="IJssel" />
17    </a>
18  </figure>
19</div>

CSS

 1div.gallery {
 2  display: flex;
 3  flex-wrap: wrap;
 4  gap: 1rem;
 5  justify-content: space-between;
 6  max-width: 1200px;
 7}
 8
 9div.gallery > figure {
10  flex: 27%;
11  margin: 0;
12  padding: 0;
13}
14
15div.gallery.two > figure {
16  flex: 47%;
17}
18
19.lightbox {
20  background-color: #000000ef;
21  color: #fafafa;
22  display: none;
23  font-size: 32px;
24  font-weight: 900;
25  height: 100%;
26  left: 0;
27  overflow: auto;
28  position: fixed;
29  top: 0;
30  width: 100%;
31  z-index: 1;
32}
33
34.lightbox a:link,
35.lightbox a:visited {
36  color: #ffffff;
37  text-align: center;
38  text-decoration: none;
39  width: 10%;
40}
41
42.lightbox > a:link,
43.lightbox > a:visited {
44  position: fixed;
45  right: 0px;
46  z-index: 2;
47}
48
49.lightbox > div {
50  align-items: center;
51  display: flex;
52  height: 100%;
53  justify-content: space-between;
54  width: 100%;
55}
56
57.lightbox img {
58  -webkit-animation: fadeIn 0.5s;
59  animation: fadeIn 0.5s;
60  max-height: 90%;
61  max-width: 80%;
62  width: auto;
63}
64/* Media queries */
65@media screen and (max-width: 800px) {
66  div.gallery > figure {
67    flex: 47%;
68  }
69}

Most recent version

The above download link gives you the version at the time of writing this article. The most recent version in Git can be found at Codeberg.

Web server setup with OpenBSD

Jochem Kossen — Tue, 20 Jun 2023 00:00:00 +0000

As a hobby, I host my website on my own server. It’s currently running the OpenBSD operating system. OpenBSD comes with batteries included. Among other things, it comes with a web (http / https) server, a transparent proxy and load balancer, a mail (SMTP) server, the OpenSSH shell server and a packet filter (“firewall”). Everything you need to host your website yourself. All nicely integrated. All for free.

OpenBSD is very consistent, lightweight and probably the most secure functional operating system available. Maintenance is a breeze, so it’s great for serving purposes.

Want to setup your own OpenBSD box? Then it can be helpful to see how other people have configured their machines.

Below you can find most of my configuration files.

By the way, I owe credit to Derek Sivers. While setting up OpenBSD and searching information about it I came across his website. He has quite some sensible things to say that rhyme with things I want to accomplish.

You might want to read his Tech Independence tutorial on how to set up your own server.

Doas

Doas is a replacement for sudo developed by the OpenBSD developers. It allows you to execute commands as another user. I’ve set it up to allow users in the wheel group to execute any command as root.

/etc/doas.conf

 1# $OpenBSD: doas.conf,v 1.1 2016/09/03 11:58:32 pirofti Exp $
 2# Configuration sample file for doas(1).
 3# See doas.conf(5) for syntax and examples.
 4
 5# Non-exhaustive list of variables needed to build release(8) and ports(7)
 6#permit nopass setenv { \
 7#    FTPMODE PKG_CACHE PKG_PATH SM_PATH SSH_AUTH_SOCK \
 8#    DESTDIR DISTDIR FETCH_CMD FLAVOR GROUP MAKE MAKECONF \
 9#    MULTI_PACKAGES NOMAN OKAY_FILES OWNER PKG_DBDIR \
10#    PKG_DESTDIR PKG_TMPDIR PORTSDIR RELEASEDIR SHARED_ONLY \
11#    SUBPACKAGE WRKOBJDIR SUDO_PORT_V1 } :wsrc
12
13# Allow wheel by default
14permit persist keepenv :wheel

Web

OpenBSD includes acme-client which I use to create and manage my SSL certificates from Let’s Encrypt. ACME stands for “Automatic Certificate Management Environment”.

For the Web server I use OpenBSD’s included httpd. It works fine for serving plain html. For more complex needs it supports the FastCGI protocol.

I also use relayd as a proxy server. It allows me to (among other things) add CSP (Content Security Policy).

acme-client

Certificate configuration

/etc/acme-client.conf:

 1#
 2# $OpenBSD: acme-client.conf,v 1.4 2020/09/17 09:13:06 florian Exp $
 3#
 4authority letsencrypt {
 5	api url "https://acme-v02.api.letsencrypt.org/directory"
 6	account key "/etc/acme/letsencrypt-privkey.pem"
 7}
 8
 9authority letsencrypt-staging {
10	api url "https://acme-staging-v02.api.letsencrypt.org/directory"
11	account key "/etc/acme/letsencrypt-staging-privkey.pem"
12}
13
14domain jkossen.nl {
15	alternative names { www.jkossen.nl }
16	domain key "/etc/ssl/private/jkossen.nl.key"
17	domain full chain certificate "/etc/ssl/jkossen.nl.fullchain.pem"
18	sign with letsencrypt
19}

To request your certificate, first set up httpd and relayd as below since it serves the acme challenge, then execute:

1$ doas acme-client -v jkossen.nl

Check certificates daily

/etc/daily.local:

1next_part "Refreshing Let's Encrypt certificates:"
2
3acme-client jkossen.nl && rcctl reload relayd

Make a symlink to the certificate

TODO: There’s a good reason to do this, but I forgot …

1$ cd /etc/ssl
2$ doas ln -s jkossen.nl.fullchain.pem jkossen.nl.crt

httpd

`/etc/httpd/httpd.conf`

 1# $OpenBSD: httpd.conf,v 1.22 2020/11/04 10:34:18 denis Exp $
 2
 3#
 4# jkossen.nl
 5#
 6server "jkossen.nl" {
 7	listen on 127.0.0.1 port 8080
 8	root "/jkossen.nl/public"
 9	log style forwarded
10	location "/.well-known/acme-challenge/*" {
11		root "/acme"
12		request strip 2
13	}
14	location match "/posts/(.*)" {
15		block return 301 "https://$HTTP_HOST/%1"
16	}
17	location "/*" {
18		directory auto index
19	}
20}
21
22server "jkossen.nl" {
23	alias "www.jkossen.nl"
24	listen on * port 80
25	location "/.well-known/acme-challenge/*" {
26		root "/acme"
27		request strip 2
28	}
29	location "/*" {
30		block return 301 "https://$HTTP_HOST$REQUEST_URI"
31	}
32}
33
34server "www.jkossen.nl" {
35	listen on 127.0.0.1 port 8080
36	log style forwarded
37	block return 301 "https://jkossen.nl$REQUEST_URI"
38}
39
40types {
41	include "/usr/share/misc/mime.types"
42
43	# by default httpd serves ascii, not utf-8
44	"application"/"rss+xml; charset=utf-8"			rss
45	"text"/"html; charset=utf-8"				html htm shtml
46	"text"/"plain; charset=utf-8"				txt
47	"text"/"xml; charset=utf-8"				xml
48	"text"/"markdown; charset=utf-8"			md
49}

relayd

`/etc/relayd/relayd.conf`

 1ipv4="192.168.2.10"
 2ipv6="2a02:a442:243a:1:221:86ff:fe9e:c2c4"
 3
 4table <local> { 127.0.0.1 }
 5
 6http protocol https {
 7	tls ciphers "ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256"
 8
 9	tls keypair "jkossen.nl"
10
11	match request header append "X-Forwarded-For" value "$REMOTE_ADDR"
12	match request header append "X-Forwarded-Port" value "$REMOTE_PORT"
13
14	match response header set "Referrer-Policy" value "same-origin"
15	match response header set "X-Frame-Options" value "deny"
16	match response header set "X-XSS-Protection" value "1; mode=block"
17	match response header set "X-Content-Type-Options" value "nosniff"
18	match response header set "Strict-Transport-Security" value "max-age=31536000; includeSubDomains; preload"
19	match response header set "Content-Security-Policy" value "default-src 'self'"
20	match response header set "Permissions-Policy" value "accelerometer=()"
21	match response header set "Cache-Control" value "max-age=86400"
22
23	return error
24	pass
25}
26
27relay wwwtls {
28	listen on $ipv4 port 443 tls
29	protocol https
30	forward to <local> port 8080
31}
32
33relay www6tls {
34	listen on $ipv6 port 443 tls
35	protocol https
36	forward to <local> port 8080
37}

E-mail

I use mailbox.org for my e-mail needs, and have OpenBSD set up to relay mail through them.

You don’t need to install packages. OpenBSD comes with OpenSMTPD installed.

`/etc/mail/smtpd.conf`

 1#	$OpenBSD: smtpd.conf,v 1.14 2019/11/26 20:14:38 gilles Exp $
 2
 3# This is the smtpd server system-wide configuration file.
 4# See smtpd.conf(5) for more information.
 5
 6table aliases file:/etc/mail/aliases
 7table secrets file:/etc/mail/secrets
 8
 9listen on socket
10
11# To accept external mail, replace with: listen on all
12#
13listen on lo0
14
15action "local_mail" mbox alias <aliases>
16action "mailbox" relay host smtps://account1@smtp.mailbox.org auth <secrets>
17#action "outbound" relay
18
19# Uncomment the following to accept external mail for domain "example.org"
20#
21# match from any for domain "example.org" action "local_mail"
22match from local for local action "local_mail"
23#match mail-from "@jkossen.nl" for any action "mailbox"
24match from local for any action "mailbox"
25#match from local for any action "outbound"

`/etc/mail/secrets`

Create this file containing your mailbox.org credentials.

1account1 me@mydomain.com:myPa$$w0rd

Replace me@mydomain.com with your mailbox.org user name (which should be your full e-mail address). Replace myPa$$w0rd with your password.

NOTE: account1 in smtps://account1@smtp.mailbox.org in smtpd.conf refers to account1 in /etc/mail/secrets.

If you change it, change both.

Set permissions

Make sure only root and smtpd can read your account information and password.

1$ doas chown root:_smtpd /etc/mail/secrets
2$ doas chmod 0640 /etc/mail/secrets

Imagine you are Jochem ... The Writer

Jochem Kossen — Mon, 12 Jun 2023 00:00:00 +0000

Imagine you, being me.

You have this vague sense of an idea.
It has to get out.
You feel you have to write it into a story.
Or a book perhaps!
You could just start.
Typing one letter after another.
But you want to do this right.
You decide to immerse yourself in the art of writing.

You read every book on writing you can find.
But you only remember On Writing by Stephen King.
In your defense, that’s a good one.
One thing you learn is that you have to read a lot of books.
So you read.

Every night before sleeping, you read a few pages.
One year later, you have read a grand total of six books.
Somehow, six does not seem much.
But what can you do?
You can start writing, that’s what you can do!

You use Hacker News as a procrastrinating device.
A few evenings.
A week.

Eventually, you come up with a plot for your book.
And decide to buy Scrivener.
It’s great for writing books.
Stephen King is a pantser.
So you should be one too.
You start typing.

It’s amazing.
Somehow, letter after letter gets written down.
It will become the next New York Times Best Seller.
Of course it will.

A few weeks later you notify your significant other about your writing endeavors.
She hears you saying the name of the main character.
She pulls a funny face.
One that you have never seen before.
That could be a good thing.
But it’s not.

You decide to rethink your plans.
And let your story simmer for a few days.

Six months later you rediscover the written chapters for your book.
You even like some of your ideas!
You decide to improve your text and carry on.

You decide all possibilities Scrivener offers are distracting.
You buy iAWriter.
You convert the book to Markdown.
It’s great.
Really.

Until you decide you want to write on Linux.
iAWriter does not run on Linux.
You rediscover Emacs.
You discover Jay Dixit, a successful author who writes using Emacs!
Jay explains how he has configured his Emacs.
It’s great.

Jay uses org-mode.
So you convert your Markdown into beautiful .org files.
You’re in heaven now.
Life is awesome.

Except…
You thought you had written three chapters in the last year or so.
Now you can only find some notes.
And a single chapter.
But it’s an old version.

In 2023, you discover something.
You haven’t touched your text for three years.
But any day now …

That’s right.
That’s you, being Jochem the Writer.
You are being me.

Long(er) Term Software

Jochem Kossen — Thu, 08 Jun 2023 00:00:00 +0000

Abstract

Occasionally I think about the software I use. Why do I get excited about running the latest and greatest? I guess I’m not as immune to fancy marketing as I would like to be. I might have found a cure, though.

How it started

Recently whenever I throw away plastic in our plastic bin (we do separate waste!), I’m shocked to see how much plastic we use. It’s terrible and I am ashamed. It encouraged me to find ways to use less plastic. And reduce waste in general.

Other events led me to Roman Krznaric’s book The Good Ancestor: How to think Long Term in a Short-Term World.

Which made me think about how I could be(come) a better ancestor. And perhaps even a Time Rebel ;-)

I wanted to find out more about the author. So I started looking for podcast interviews with Roman. I came across the (mostly dutch) Plant podcast of Nynke Laverman. In it, she and Lex Bohlmeijer interview twelve scientists, philosophers and artists who inspire her. Also, she strives for and mostly achieves a zero-waste lifestyle. And she describes how she did it.

One of the sticking parts for me is about taking more than giving. And not expecting a reckoning some day.

So … what?

What does all this have to do with this article? For a good part, it’s about mindset. I’m trying to reduce consumerism, waste and the unnecessary in general. Software is a significant part of my life. What happens when you apply the same mindset to software?

Most people use software produced by big corporations. Microsoft, Apple, Adobe and so on. Those mostly produce closed, proprietary products. And are moving their software and your data to their clouds more and more. Meaning those corporations mostly decide what the consumer can do with their software. And for how long. It’s not you deciding what you can do with your data. It’s them deciding what you may and may not do with your data. Oh, and they might as well use your data to their advantage. These corporations top priority is to make money. They collect your data to exploit it so they can make more money out of it.

It’s not just about the software itself. It’s about the data it produces as well. Your data. The formats these software produce and use are often proprietary. They store your data in closed formats which you can only use with their software.

To quote my favorite band Elbow, “Empires crumble all the time”. If the software disappears, good luck with your data. Think about your photo library, your digital letters, notes, etcetera. Do you even realize what and how much data you have? Which parts of it would you like to preserve? Would you like to use software from a competitor? You’re in luck if you’re able to transfer your data. If so, now two corporations have access to your data.

I’m typing this text in a text editor called GNU/Emacs. Which has been around since 1976. I wasn’t even born yet. I’ve been using Emacs on and off for about 20 years now. It has been mostly consistent in how to use it throughout all this time. I imagine it will still be usable 20 years from now.

Operating Systems

The Proprietary world

What would a desktop operating system for the long haul look like? It won’t be Microsofts Windows. Windows grows and changes and gains weight with every release. When Microsoft announced Windows 11 it only worked on CPU’s produced in the last few years. They do things like this all the time. Causing perfectly usable hardware to be thrown with the trash. Such a waste. That’s not the way. Though Apple seemingly supports MacOS for longer, it still doesn’t support hardware from just ten years ago. Apple also is not the way.

The systems Microsoft and Apple produce are closed source, proprietary products. Closed source systems cannot be trusted for long term computing.

The Open Source world

Most known Open Source products include Linux, FreeBSD, OpenBSD and NetBSD.

All offer a bigger degree of separation between the operating system and the software that runs on top of it. Consumers not only have choices in client software, but in graphical interfaces as well. Which means there is a lot of choice.

The biggest graphical environments are Gnome and KDE. Both are changing continuously. Growing continuously. Chasing MacOS and Windows in an attempt to compete. Which on one hand excites consumers including myself.

Wouldn’t software be less fragile if it did not change as much? If developers would focus more on fixing existing code? If software contained less lines of code?

With each new release of the GTK or Qt toolkits, large parts of Gnome and KDE have to be rewritten. Just to offer the same functionality.

There are other options like IceWM. It has been around since 1997 and is still actively maintained. But it works with the X Window System protocol only. Most Linux distributions are shifting towards Wayland as a replacement for Xorg.

A few thoughts about the BSD’s

If you have used FreeBSD 20 years ago, chances are good you’ll feel right at home with the current version. Same goes for OpenBSD. I did. OpenBSD with its CalmWM Window Manager does have a learning curve. It’s not considered user friendly. But it is consistent. If I were to install OpenBSD 30 years from now, and OpenBSD is still actively developed, chances are good it will still work about the same way. So if I learn to use it now I can still work the same way 30 years from now. Wouldn’t that be user friendly? It has a learning curve. Is that so bad if there is great documentation available? What about webbrowsers constantly “needing” new functionalities to support the latest on the web?

Solutions

A different operating system

A simple operating system with graphical environment integrated. Without choice in graphical environments. With great documentation. Developed around toolkits and libraries that last.

Are enough developers and users interested in making this?

Recipes

Would it be possible to write recipes to achieve the above? Defining criteria that last a long time. When executing, it sets up your system and software according to the criteria. Using the same software when possible. But if not, setting up alternatives the same way as much as possible. Recipes could be made for several operating systems. Imagine having MacOS and OpenBSD setup the same way. It would be possible to make use of existing solutions.

Sounds doable right?

Closing thoughts

After getting the above out of my head, some words keep floating in my head. Curious to hear what other people think.

Minimal (but not too minimal, perhaps functional but no excess)
Functional
Consistency
Simplicity
Reliability
Independence
Secure
Low maintenance
Open Source
Community
Compromises (just a few)
User friendly (does it mean having a low learning curve, or being consistent?)
Timeless design

Productivity apps

Jochem Kossen — Mon, 08 May 2023 00:00:00 +0000

An app for personal to-do’s.
An app for work tasks.
An app for work notes.
An app for personal notes.
An app for reminders.
An app for calendar items.
An app for text editing.

I changed from Microsoft Todo to Todoist as well. Each has half of my tasks.

Where are those notes on the to-do item I should finish by tomorrow? You know, the to-do item I’m unable to find. I’m not sure whether it was for work, for personal or both.

This is the opposite of productive. I’m lost. Lost in the pile of apps I have accumulated. It’s like a forest but I can’t find the right tree.

No, that’s not it. Forests are beautiful.

My app collection is more like a waste dump. That’s not what I want. I want to plant a seed, water it, nurture it, see it grow into a big strong oak tree that will blossom. I’d care about that tree.

So what if I’d use a single app? What if I’d write everything down in a text editor? I could use plain text! Write down a list of tasks in a todo file. Write notes in a single file per note. A folder containing plain text files with descriptive names. Could it really be this simple?

I’d know where to find everything. I’d know where to add tasks. I’d know where to write notes.

As a side effect, plain text is very malleable. Changing the structure is easy. It can be edited with every text editor in the world. It can be searched by every app. It does not depend on commercial “cloud” services.

Plain text won’t require new hardware, ever! Plain text will survive longer than «fill in any commercial app».

Like the oak tree. It will be beautiful.

I will need to take care of it. Prune it at the right moments. Make sure it will get the right nutrients in the correct amounts.

And who knows, perhaps one day, it will even give acorns!

I need to put in effort. But that will only make me care more about it.

I will still use a calendar app as well. Calendars are great for visualizing time, scheduling and inviting other people.

Learning Scheme

Jochem Kossen — Sun, 03 Jan 2021 00:00:00 +0000

At work, we talked our first-year students into participating in the Advent of Code 2020. It’s quite the challenge for them, but quite a few had a lot of fun solving the puzzles together. They mostly utilize PHP and JavaScript.

As a fun project I thought I’d participate as well and use the occasion to learn a different way of programming as an extra challenge. Ever since rediscovering Emacs I’ve been wanting to understand elisp better. Up to now I just considered LISP to be an annoying collection of parentheses containing bits of code. LISP code looks a bit like it was written by aliens. After considering a few options (Emacs with elisp, Common Lisp, Racket, Scheme). I picked the GNU Guile Scheme implementation.

Scheme is considered a minimal Lisp variant which made me think it’d be one of the easier options to start with. While not strictly required in Scheme, one of my personal goals was diving into functional programming, recursion and avoiding side-effects. Which meant I could not use iteration (for, foreach, while) and I was not allowed to mutate variables (change their values).

When telling my students they wondered if it was at all possible to write working code this way. We’ve only been teaching them imperative coding styles with some Object Orientated Programming up to now.

Challenging

For me, it did turn out to be quite the challenge. It does not help that there are multiple implementations of Scheme such as Guile, Chez, and Chicken Scheme. Each implement Scheme in slightly different ways. So when finding documentation online, you have to keep in mind the code will need adjustments in order to work in the specific Scheme implementation that you use. The documentation of Guile itself is lacking in giving examples.

Still, when writing this post, I’ve solved everything up to day 5, and I feel I am getting better thinking in recursive functions.

Here’s my solution to day 1, my very first Scheme code. It works but is still full of newborn-schemer-ugliness.

 1(define (do-num lst-a lst-b i)
 2  (define l (car lst-a))
 3  (define r (car lst-b))
 4  (define sum (+ l r))
 5  (if (= sum 2020)
 6      (format #t "\nFOUND: ~d+~d=~d\nSolution: ~d\n" l r sum (* l r)))
 7  (if (> (length lst-a) (+ i 1))
 8      (do-num lst-a (cdr lst-b) (+ i 1))
 9      (if (> (length lst-a) 2)
10          (do-num (cdr lst-a) (cdr (cdr lst-a)) 1))))
11
12(do-num lst (cdr lst) 1)

After programming with it a few more days, it gets better though. Day 5 looks like this:

 1(use-modules (srfi srfi-9) (ice-9 format) (ice-9 regex) (ice-9 match) (ice-9 rdelim))
 2
 3(define (parse-row chars res lower-char upper-char start end)
 4  ;;(format #t "start: ~a end: ~a\n" start end)
 5  (if (= (length chars) 0)
 6      res
 7      (let ((char (car chars)))
 8        (cond ((equal? lower-char char)
 9               (parse-row (cdr chars)
10                          start lower-char upper-char start
11                          (floor (+ start (/ (- end start 1) 2)))))
12              ((equal? upper-char char)
13               (parse-row (cdr chars)
14                          end lower-char upper-char
15                          (ceiling (+ start (/ (- end start) 2)))
16                          end))))))
17
18(define (get-seat-id pass)
19  (let* ((row (string-drop-right pass 3))
20         (col (string-drop pass 7))
21         (rowl (string->list row))
22         (coll (string->list col))
23         (res-row (parse-row rowl 0 #\F #\B 0 127))
24         (res-col (parse-row coll 0 #\L #\R 0 7)))
25    (+ (* res-row 8) res-col)))
26
27(define (get-pass-list port pass-list)
28  (let ((line (read-line port)))
29    (if (eof-object? line)
30        (sort pass-list <)
31        (let ((seat-id (get-seat-id line)))
32          (get-pass-list port (cons seat-id pass-list))))))
33
34;; find missing pass in _sorted_ list
35(define (get-missing pass-list)
36  (if (not (= (cadr pass-list) (+ (car pass-list) 1)))
37      (+ (car pass-list) 1)
38      (get-missing (cdr pass-list))))
39
40;; Correct solution: 739
41(define file (open-input-file "aoc5_input.txt"))
42(define missing (get-missing (get-pass-list file (list))))
43(format #t "Solution: ~a\n" missing)
44(close-input-port file)

Want to see more? Check my Git repository

Gains

Functional programming requires one to think different. You have to be more creative in finding a solution that works.
After writing code like this for a few days, the parentheses seem to fade into the background.
I find reading LISP code much easier now.
There’s not a whole lot of grammar in Scheme, which makes all Scheme code look quite consistent, and thus easier to understand.

Aside from that, Scheme re-peeked my interest in programming languages. I’ve been looking into Haskell which looks super nice and Rust which is currently hyped everywhere. Both are completely different beasts from Scheme but very interesting nonetheless.

Lasting code

Another aside, looking into Scheme and LISP made me think about writing long(er) lasting code. Scheme has been around for 40 years. Scheme code still looks about the same as it did back then. You can still use Scheme (and LISP) to write modern software.

One of the things annoying me at writing code is that most code will stop running once a newer version of the it’s mostly the frameworks (Laravel, Spring MVC, ASP.net, etc.) which don’t seem to care about keeping code working.

If you’d want to write code which will still compile and run a hundred years from now, which programming language / environment would you use?

Want to dive into Scheme as well?

If you want to dive into Scheme as well, here are a few resources which helped me along the way:

Structure and Interpretation of Computer Programs
The Little Schemer, there are freely downloadable PDF’s which can be found in your nearest search engine.
A Guile Mind Book

File format considerations

Jochem Kossen — Sun, 22 Nov 2020 00:00:00 +0000

When writing

I just want to read what I have written.
And write what I have not.
In other words I only want to deal with the contents.

I don’t want to get distracted by … features
Such as markup.
Or alignment.
Or shapes.
Or decoration.

My files should be backed up easily. To “the cloud” ¹. Or to other computers.

I want to edit on my computer.
Not in “the cloud”.

I should still be able to work on my files

When my editor software ² stops working.
When my computer stops working.
When my operating system vendor decides to go bankrupt. ³
When I decide I want to work on a different operating system.
Now and in the future.

As for what I have written

Software in 2035 should be able to open it correctly.
It should be readable and editable in multiple programs.
It should be convertable into modern formats (HTML for the web)
I want to see changes I make to lines I wrote easily
Searching should work well across multiple documents

In short

Proprietary formats are out of the question
“Document” formats (docx, odt, …) just complicate things

Plain text

There is only one right option: Plain text.
With Markdown ⁴ to add some fringe.

If you’re reading this in 2035 and have no clue what a “cloud” is, it’s a different word for services provided on the internet. ↩︎
GNU Emacs has been in development since the 1970’s. If there will be a “100-year” editor, there’s a good chance this will be it. ↩︎
Baby, empires crumble all the time - Elbow. ↩︎
Yes I know org-mode. Yes I like org-mode. But Markdown is everywhere. org-mode is mostly just Emacs.
Yes Markdown is limiting. Its limits prevent me from overusing it. I like that. Yes I know about asciidoc, asciidoctor and RestructuredText too ↩︎

Blog posts in English on jkossen.nl

A few examples of and notes on Podman quadlets

Enable automatic updates

rproxy.container

contents of rproxy.container

rproxy-data.volume

podman-ipv6.network

Simply Vim

Features

Keyboard shortcuts

A few tips on using Vim

Screenshots

Code

A simple JavaScript Lightbox without dependencies

Contents

TLDR

Abstract

Features

The Code

JavaScript

HTML

CSS

Most recent version

Web server setup with OpenBSD

Doas

/etc/doas.conf

Web

acme-client

Certificate configuration

Check certificates daily

Make a symlink to the certificate

httpd

/etc/httpd/httpd.conf

relayd

/etc/relayd/relayd.conf

E-mail

/etc/mail/smtpd.conf

/etc/mail/secrets

Set permissions

Imagine you are Jochem ... The Writer

Long(er) Term Software

Abstract

How it started

So … what?

Operating Systems

The Proprietary world

The Open Source world

A few thoughts about the BSD’s

Solutions

A different operating system

Recipes

Closing thoughts

Productivity apps

Learning Scheme

Challenging

Gains

Lasting code

Want to dive into Scheme as well?

File format considerations

When writing

I should still be able to work on my files

As for what I have written

In short

Plain text

`/etc/httpd/httpd.conf`

`/etc/relayd/relayd.conf`

`/etc/mail/smtpd.conf`

`/etc/mail/secrets`