The Raymii.org RSS feed, all about GNU/Linux, programming and other topics that interest me.
One of my all time favorite calculators is the [HP 16C] (https://en.wikipedia.org/wiki/HP-16C). It is an RPN calculator aimed at computer programmers with support for hex, binary, octal and decimal and all sorts of useful operations like bit shifting, masking and rotations. I don't own one myself, I have a [Swiss Micro's DM16L] (https://www.swissmicros.com/en/products/dm16l), a high quality modern…
The emulation space is going crazy, after my previous [post on Windows booting on DEC Alpha es40 emulator](/s/blog/Run_Windows_2000_for_Dec_Alpha_on_a_new_es40_fork.html), there is now another huge breakthrough in the emulation of other non-x86 CPU emulation. [Yufeng Gao](https://github.com/TheBrokenPipe) with help from [gdwnldsKSC](https://github.com/gdwnldsKSC) (the man behind the updated…
As you might know, I'm involved a bit in the [OpenVMS](/s/tags/openvms.html) community and the [Alpha emulation side via AXPBox](/s/blog/AXPBox-version-1.0.0-released.html). AXPBox ([github](https://github.com/lenticularis39/axpbox)) is a fork of the es40 alpha emulator by Camiel Vanderhoeven (who is now Chief Architect at VSI, the company that makes OpenVMS, [for x86…
I've got a [long](/s/articles/Get_Started_With_The_Nitrokey_HSM.html) [history](/s/tags/hsm.html) [with](/s/tags/yubikey.html) [hardware security modules](/s/articles/Nitrokey_HSM_web_cluster.html), both professionally and for fun. For the longest time, my SSH private key has lived inside a hardware token of some sort, be it the Nitrokey, the Smartcard-HSM or a Yubikey. The private key never…
Ansible recently stopped working on one of my older servers. The playbooks wouldn't execute anymore, with a cryptic python error. With Ansible 2.14 this server worked, after upgrading to 2.19 the playbooks failed. It turned out that the Python version on the server was too old. This server runs Ubuntu 18.04, that ships with Python 3.6. That server still gets updates via Canonicals Ubuntu Pro…
Proxmox VE is a virtualization platform, like VMWare, but open source, based on Debian. It can run KVM virtual machines and Linux Containers (LXC). I've been using it for over 10 years, the [first article I wrote mentioning it was in 2012](/s/tags/proxmox.html). At home I have a 2 node Proxmox VE cluster consisting of 2 HP EliteDesk Mini machines, both running with 16 GB RAM and both an NVMe and…
I recently found a Navman Bike 1000 in a thrift store for EUR 10. This is a bike computer, a navigation device for cyclists, made by MiTaC, the same company that makes the Mio bike computers. This Navman Bike 1000 is a rebadged `Mio Cyclo 200`. It's from 2015 and as you might have guessed, no more map updates. This article shows how I dabbled a bit in reverse engineering, figuring out the device…
In this post, we'll walk through a fully declarative, Kubernetes-native setup for running a highly available MQTT broker using Eclipse Mosquitto. This configuration leverages core Kubernetes primitives (`Deployments`, `Services`, `ConfigMaps`, and `RBAC`), alongside Traefik `IngressRouteTCP` to expose MQTT traffic externally. It introduces a lightweight, self-healing failover mechanism that…
I'm pleased to announce the next version of Leaf Node Monitoring, the simple and easy to use open source site and server monitoring tool. This update adds two features users have requested, plus a couple of small but useful fixes. This post goes over everything that is new in this release.
For almost 5 years I've been using the `mqtt-data-logger` [python script](https://github.com/RaymiiOrg/mqtt-data-logger) to log all MQTT communication. This script works, but is a bit limited in how it stores logs (files per time it's started) and it often can't keep up with the message rate (tens of thousands per second) of my mqtt brokers. So I've written a new tool in C++ to log all MQTT…
As of the 18th of February, OpenVMS, known for its stability and high-availability, 47 years old and ported to 4 different CPU architecture, has a package manager! This article shows you how to use the package manager and talks about a few of its quirks. It's an early beta version, and you do notice that when using it. A small list of things I noticed, coming from a Linux (apt/yum/dnf) background:…
I'm using the Headlamp dashboard for my [high-available local kubernetes cluster](/s/tutorials/High_Available_k3s_kubernetes_cluster_with_keepalived_galera_and_longhorn.html) because I find that to be faster, more clear and useful than the full blown Kubernetes Dashboard. In [my first…
This is the result of my first attempt at learning KiCad during the Christmas break. I love the sound of a relay, so trying out [these relay logic gates](https://www.youtube.com/watch?v=_nXc439NTYk) from the Usagi video and the information [here on the MERCIA relay computer](https://web.archive.org/web/20250104211313/https://relaiscomputer.nl/index.php/elements) on a breadboard was fun, but a bit…
You probably recognise this situation. You're working on your code and realise that the thing you're writing might take long, be blocking or is batch-wise. It might be resizing images, calling some API or processing hardware inputs or a stream of incoming messages. These tasks, if not handled efficiently, can halt your application, leaving it unresponsive. To avoid this, one solution is to offload…
Sherlock Holmes tackles a modern computing dilemma involving a missing system call. In this case, a frustrated developer attempts to port an embedded device running Yocto to a newer version, only to be met with `Error 38` due to a missing syscall. Holmes and Watson delve into the intricacies of kernel versions, glibc, and system calls to uncover the truth behind the missing `syscall_397` and…
I recently faced a challenging issue with an application that wasn't shutting down correctly, either segfaulting or terminating without an active exception. Running the program via `valgrind` to check for memory leaks wasn't possible because the program couldn’t perform its cleanup if it didn't shut down correctly. This article covers adding runtime instrumentation provided by `gcc` to log…
Since [DECWindows / CDE](/s/blog/OpenVMS_x86_E9.2-3_fixes_CDE_and_adds_Guest_Console.html) now works on OpenVMS x86 (from 9.2-3 onwards) there is much fun stuff to do. Back in 2021 I wrote an article on the [CDE desktop on Alpha / AXPbox](/s/blog/OpenVMS_CDE_Desktop_remote_x_axpbox.html) and also an article on how to run [CDE on modern linux, since it's still…
I'm a big fan of OpenVMS. You can [read all my OpenVMS articles here](/s/tags/openvms.html). Since the [licensing changes](https://web.archive.org/web/20240814192656/https://vmssoftware.com/about/news/2024-03-25-community-license-update/) to the Hobbyist Program, I applied and was included in to the Ambassador Program. A new update of the X86 field test is released and this includes to major…
This guide shows you how to use Role-based access control (RBAC) to create a user account that only has rights for one specific namespace. I'll also show you how to limit the resource usage of that `Namespace`. Last but not least, I'll also show you how to create a `kubeconfig` file for that specific user.
If you have [set up a Self Signed Root CA](/s/tutorials/Self_signed_Root_CA_in_Kubernetes_with_k3s_cert-manager_and_traefik.html) for your local Kubernetes Cluster and have trusted the Root Certificate, you are at risk if the key is compromised. If the key is stolen, it can be used to create trusted certificates for everything. Luckily there is something we can do, using `nameConstraints` to limit…
Now that I'm learning Kubernetes for a few weeks, I'm finally at the point where I was 20 years ago with regular boring old tech, being able to [host multiple domains](/s/tutorials/Kubernetes_k3s_Ingress_for_different_domains_like_virtual_hosts.html), [password protection](/s/tutorials/Password_protect_web_services_in_Kubernetes_k3s_traefik_with_basic_auth.html) and [high available…
The `openssl x509` command can be used to get information from a certificate. If you supply a filename, the command will only use the topmost certificate in the file, not all certificates in the file, like in the case of a certificate chain. The `openssl s_client -connect` command can connect to a server and show all certificates served by that server. The command I'm providing in this snippet…
Now that I have a [high-available local kubernetes cluster](/s/tutorials/High_Available_k3s_kubernetes_cluster_with_keepalived_galera_and_longhorn.html) and am [experimenting with deploying apps](/s/snippets/Using_nodeSelector_to_deploy_a_Kubernetes_Helm_chart_only_on_x86_or_amd64_nodes_not_arm64.html), it's also time to look into securing those apps using certificates and passwords. In this case…
I'm pleased to announce the next version of Leaf Node Monitoring, the simple and easy to use open source site and server monitoring tool. Major new features include minimizing to the tray, automatic startup on Windows and Linux and a new check, SSL Certificate Expiry. This post goes over everything that is new in this release.
My [k3s cluster](/s/tutorials/My_First_Kubernetes_k3s_cluster_on_3_Orange_Pi_Zero_3s_including_k8s_dashboard_hello-node_and_failover.html) runs on Orange Pi Zero 3 small board computers, with a 1.5 GHz Allwinner H618 Quad-Core Cortex-A53 ARM64 CPU. Nowadays most popular software has support for `aarch64` due to the popularity of boards like the Raspberry Pi and the Apple M1 series processors, but…
Now that I have a [high-available local kubernetes cluster](/s/tutorials/High_Available_k3s_kubernetes_cluster_with_keepalived_galera_and_longhorn.html) it's time to learn not just managing the cluster but actually deploying some services on there. Most examples online use a `NodePort` or a `LoadBalancer` to expose a service on a port, but I want to have domains, like,…
After my [first adventure with Kubernetes](/s/tutorials/My_First_Kubernetes_k3s_cluster_on_3_Orange_Pi_Zero_3s_including_k8s_dashboard_hello-node_and_failover.html), getting started with k3s on my small 3 node ARM cluster that [boots via PXE / NFS](/s/tutorials/Netboot_PXE_Armbian_on_an_Orange_Pi_Zero_3_from_SPI_with_NFS_root_filesystem.html), I noticed that there is only one k3s node that has the…
I've been working as an embedded C++ developer for over 5 years now so my sysadmin / devops skills are becoming a bit rusty. The odd bit of Ansible here and there but no new stuff. I figured it was time to expore Kubernetes, as it is what all the cool kids do these days. So I [got myself 3 new SBC's] (/s/tutorials/Netboot_PXE_Armbian_on_an_Orange_Pi_Zero_3_from_SPI_with_NFS_root_filesystem.html),…
Because I wanted to experiment with Kubernetes I bought a few cheap SBC's and a Power over Ethernet switch to run `k3s`. Since Kubernetes is very resource intensive I wanted to try to boot the boards via the network without causing wear on the Micro SD card. The boards have built-in SPI flash from which it can boot `u-boot` and Armbian works quite well with a root filesystem over NFS. This guide…
I'm pleased to announce the next version of Leaf Node Monitoring, the simple and easy to use open source site and server monitoring tool. Major new features include better alerting and history of events. This post goes over everything that is new in this release.
Recently I was gifted a T65 rotary telephone. This was **the** standard telephone in The Netherlands in the seventies and eighties. I remember my parents having one as well. Because this phone does not use DTMF but pulse dialing it does not work with modern equipment, like the built in telephony / voip server on my FritzBox router. Using a hardware converter it is possible to convert pulse dialing…
Adding [properties to QObject based classes](https://web.archive.org/web/20240529180113/https://doc.qt.io/qt-6/properties.html) is cumbersome. Although [the property system](https://web.archive.org/web/20240529180113/https://doc.qt.io/qt-6/properties.html) and [Signals and Slots](https://web.archive.org/web/20240529180002/https://doc.qt.io/qt-6/signalsandslots.html) are great to use, especially…
I recently had to setup a Windows development environment with Qt 5.15. Qt 5.15 is still developed by the Qt company, but only released in binary form for paying customers. The [source code is released after 1 year](/s/blog/Qt_5.15_LTS_Docker_Image_for_Android_with_OpenSSL.html#toc_0). Via the Online Installer you can only install 5.15.2 and you must login with a Qt account. This guide shows you…
The [Atgames Legends Pinball Micro](https://web.archive.org/web/20240123213954/https://www.atgames.us/products/legends-pinball-micro) is a small virtual pinball cabinet for around USD 350. I imported one to the Netherlands, Atgames does not ship here. The built in tables are okay and more are for sale via Atgames' webshop. Overall for the price it is a nice device. Build quality is okay, software…
Which Root Certificates should you trust? Did you know that any certificate authority can issue a certificate for any website? There are protocols in place so that should not happen, but when (not if, when) they get hacked or coerced by their government, they can issue a certificate to intercept secure communication for any website. I've made an open source program,…
The [YouLess](https://youless.nl/home.html) is a device that can help you monitor energy usage. It works on so called smart meters using a P1 port, it can monitor solar panels but it also works with regular old analog meters. I have an old style analog meter but I like gadgets and monitoring / reducing my energy usage just as much as the next guy so I bought one. It has an optical sensor that you…
Recently I got an email from Google regarding the API level of [Leaf Node Monitoring](https://leafnode.nl), my open source monitoring app for Windows, Linux and Android. The Play Store version must be updated to target API level 33. For Windows and Linux I'm building the app automatically in a CI environment but the Android build was still a manual process. Until now, because after a bunch of…
Qt has no `Circle` built in to QML as a basic type, as for example the `Rectangle` or the `Button` control. This post shows you how to get a `Circle` in QML, from the most basic method (a `Rectangle` with a `radius` of 180) to more advanced methods, using the `Canvas` JavaScript API (which allows us to draw a partially filled Circle, for a Pie Chart) and a `c++` control based on…
This is a static site, meaning that no server-side processing occurs. All HTML is generated out of a few folders full of markdown source and then uploaded to the cluster. Searching on this site was always provided by a text-box form that sent you to google with 'site:raymii.org' appended to it. Works fine, but it sends all data to Google. With my recent removal of all Google Ads on this site, as…
I like to tinker with old hardware. The [DEC](https://raymii.org/s/tags/dec.html) PDP-8 is my favorite [retro computer](/s/tags/pdp-8.html) and [Office 2003](/s/blog/Using_a_Windows_Mobile_2003_PDA_hp_ipaq_in_2022_including_whatsapp.html) is the best version ever released IMHO. One of my other favorite retro devices is the HP Jornada 720. A small `handheld PC` (smaller than a netbook) running…
This guide shows you how to run `Vi` without an operating system, bare metal. This is a follow up on my article from 2014 where I made a custom linux distro that would [Boot to Vim, VIM as PID 1](https://raymii.org/s/blog/Vim_as_PID_1_Boot_to_Vim.html). This time we go further, we boot into `Vi` without an operating system. This is made possible by…
This article shows you how to install HAProxy on OpenVMS 9.2 for x86. I've often used HAProxy in my career as a sysadmin and find it a very useful tool. HAProxy is an open source, fast, reliable load balancer for TCP and HTTP-based applications. This guide assumes you've set up your OpenVMS system via [my guide](https://raymii.org/s/blog/OpenVMS_9.2_for_x86_Getting_Started.html) and the [second…
OpenVMS on x86 is now available for hobbyists! Almost a year after [the official release](/s/blog/OpenVMS_9.2_for_x86_will_be_released_tomorrow.html). This is a part 3 of my getting started guide. Part 2 ended with a working network setup and SSH access. In part 3 we'll do something very exciting, installing the WebUI, a web based management interface for OpenVMS. I'll also share a few smaller…
OpenVMS on x86 is now available for hobbyists! Almost a year after [the official release](/s/blog/OpenVMS_9.2_for_x86_will_be_released_tomorrow.html). This is a part 2 of my getting started guide. [Part 1](https://raymii.org/s/blog/OpenVMS_9.2_for_x86_Getting_Started.html) ended with an installed system, this part continues with automatic startup, activating the license files (PAKs) and setting up…
OpenVMS on x86 is now available for hobbyists! Almost a year after [the official release](/s/blog/OpenVMS_9.2_for_x86_will_be_released_tomorrow.html). This is a part 1 of my getting started guide, showing you how to install OpenVMS on VirtualBox on Windows 10/11. More parts will follow, documenting license installation, network setup, ssh, application installation etc.
OpenVMS x86 is now available for (most) hobbyists! Almost a year after [the official release](/s/blog/OpenVMS_9.2_for_x86_will_be_released_tomorrow.html) most hobbyists can now login to the [Service Portal](https://sp.vmssoftware.com) to download their copy of OpenVMS 9.2 for x86, `X86E921OE.ZIP` and the PAK (license) files (`x86community-20240401.zip`), valid until April 2024.
A small site update this time, just to let you know that I've added a cookie consent popup to this static site. If you reject all cookies, you should not see any advertisements and aren't tracked by Google Analytics. It's open source, cookieconsent by Orest Bida.
During a recent code review I found a hard to spot bug, a misplaced parenthesis in an `if` statement. I often employ a technique I call `named booleans`, which would have prevented this bug. It's a simple technique, instead of a long `if` statement, give every comparison a seperate boolean variable with a descriptive name and use those variables is the `if` statement. This post shows the bug in…
I've seen many C++ code bases where there was the concept of a service locator. An global static object that anyone can query to get a class. This is handy with old legacy spiderweb intertwined code that gets everything from everywhere, but not so useful when you're trying to unit test code, it is not visible from the header what dependencies you need. My preference goes to dependency injection,…
Recently a few of my Ubuntu 20.04 and Debian 11 servers failed to run an `apt update` because it insisted that the HTTPS certificate for a repository could not be validated, while `curl` on the same system had no issues connecting. Join me on a deep dive into certificate validation and troubleshooting `apt`, digging into the C++ source code for `apt` and `GnuTLS` and in the end, it turned out to…