Our Blog

SSH and Old Servers

By Josh Ausborne
July 21, 2023

We recently updated one of our backup servers from Oracle Linux 8 to Oracle Linux 9, a free rebuild of Red Hat Enterprise Linux 9, also known as RHEL 9. As with any newer OS, there are bound to be unexpected little differences which crop up and which need to be handled.

In the case of our backup server, we found that it could no longer SSH to older servers, which includes a couple running CentOS 5 (yes, there really are a few of those out in the wild), some CentOS 6, and one Debian 8. We saw similar connection problems when we first went from CentOS 7 to Oracle Linux 8, and we addressed the issues by creating a Host entry for the servers in our ~/.ssh/config file.

Here is an example of of the entry that we used previously:

Host old-server-1 old-server-2 old-server-3
  User root
  Hostname %h.example.com
  KexAlgorithms +diffie-hellman-group-exchange-sha1

This worked fine for a couple of years until we upgraded from Oracle Linux 8 to 9. At this point we started to see a different problem when trying to connect.

Unable to negotiate with <nnn.nnn.nnn.nnn> port 22: no matching host key type found. Their
offer: ssh-rsa,ssh-dss

Troubleshooting

One of the good troubleshooting …

CSTE Conference 2023 Retrospective

By Samuel Stern
July 14, 2023

End Point is proud to have been an exhibitor at the 2023 Council of State and Territorial Epidemiologists (CSTE) conference in Salt Lake City, Utah.

We are grateful to have had the opportunity to showcase our public health software suite offering, CasePointer, to numerous state, tribal, territorial, and international epidemiologists.

The conference served as a meeting place to hear about the latest research in the fields of informatics and disease surveillance, and discuss the future of data management on state and national levels, with many talks exploring the technologies that will become future standards and practices.

The End Point booth was abuzz with visitors getting hands-on demos using the EpiTrax software as well as learning about the other aspects of the CasePointer suite, such as the Electronic Message Staging Area (EMSA), our new disease reporting portal, and the EpiTrax NMI module.

The CasePointer demo highlighted its capability of streamlining the management of epidemiological data with a user-friendly and highly customizable interface.

The CSTE conference provides a valuable opportunity to engage with epidemiologists and gain insights into the daily obstacles they …

Unix tools & tips

By Muhammad Najmi bin Ahmad Zabidi
July 5, 2023

The command line interface (CLI) programs/​tools found on UNIX-like (*NIX) systems are among the most useful tools available to system administrators. CLI tools allow a system administrator to handle the *NIX systems either remotely or locally without needing to install Graphical User Interface (GUI) packages.

Almost twenty years ago, I bought two O’Reilly books: “sed & awk, second edition,” written by Dale Dougherty & Arnold Robbins, and “Mastering Regular Expressions,” written by Jeffrey E.F. Friedl. These two books were printed in the late ’90s, and I bought them in 2004. I remembered them recently when my co-workers and I held a few study sessions to learn regular expressions. When a page and chapter are mentioned in this post, I’m referring to the editions of these books printed in that particular year.

In this blog post, I’ll detail some common use cases I encounter day to day, as well as some related tools that help me handle them.

sed

During my regular work as a system administrator, I usually use sed (“stream editor”) to do string replacement across files and awk for log files or file analysis with arbitrary strings …

Rocky Linux 9 at Hetzner Robot Made Quick and Easy

By Jeffry Johar
July 1, 2023

Image by Jeffry Johar

Introduction

In my last blog post, I shared my experience of installing Rocky Linux 8 on my Hetzner robot server and subsequently upgrading it to Rocky Linux 9.

Rocky Linux project manager Brian Clemens said that method is not recommended and suggested using a boot kickstart for an automated installation. Thanks, Brian!

Despite my attempts to utilize kickstart, I encountered difficulties in booting my NVMe disk. During this process, I discovered another workaround for installing Rocky 9 using the installimage script. This method is also experimental, just like the previous one.

The Steps

1. Access the rescue mode (refer to my previous blog post if you need guidance).

2. Copy the existing Rocky Linux 9 image to Rocky Linux 8 and place it in the root directory with the following command:

   cp /root/images/Rocky-91-amd64-base.tar.gz /root/Rocky-87-amd64-base.tar.gz

The filename should adhere to the required naming convention for the installimage script to function correctly.

3. Launch the installimage and select the Custom Image option.

   

4. Configure the disk settings as required, and at the end of the script, select the image accordingly.

   IMAGE …

Migrating Rails 6 React to Rails 7 React

By Indra Pranesh Palanisamy
June 26, 2023

CasePointer’s disease reporting portal is built on React and Rails 6, and it’s time for an upgrade to Rails 7. This blog post will cover the steps, benefits, and challenges of migrating from Rails 6 to Rails 7, and offer valuable insights into the world of Ruby on Rails.

With the recent release of Rails 7, there are many new features and improvements to explore. One of the biggest changes in Rails 7 is the retirement of Webpacker in favor of using the native webpack for bundling JavaScript.

For those who are not familiar, Webpacker is a Rails gem which is a wrapper around the webpack build system that provides a standard webpack configuration and reasonable defaults.

Steps for migrating Rails 6 React to Rails 7 React

To migrate a Rails 6 React application to Rails 7 React, follow these steps:

1. Update the Rails Gem in the Gemfile

In your application’s Gemfile, update the Rails gem version to Rails 7:

-gem "rails", "~> 6.1.4"
+gem "rails", "~> 7.0.0"

2. Upgrade Rails packages

Upgrade the Rails packages using Yarn:

yarn upgrade @rails/actioncable --latest
yarn upgrade @rails/activestorage --latest

3. Run the Rails update task …

Announcing CasePointer

By Jon Jensen
June 20, 2023

Photo by Diva Plavalaguna, Pexels license

End Point is pleased to announce CasePointer, the expanded branding of our line of public health systems and services. Before this we referred to it simply by the name of one of its components, EpiTrax.

The name CasePointer more appropriately reflects the broad scope of services we provide within the disease reporting and surveillance sector.

This change coincides with the launching of the dedicated CasePointer website at www.casepointer.com and our participation next week in this year’s conference of CSTE (Council of State and Territorial Epidemiologists) in Salt Lake City, Utah. We will be staffing a booth there on the exhibition floor. Come visit us!

Starting in 2008, End Point helped develop and maintain the TriSano open source disease surveillance system. In 2019 we migrated our customer, the Kansas Department of Health and Environment, from TriSano to a new disease surveillance system called EpiTrax, which was developed by the state of Utah, and is also open source.

This timeline shows those and other key points on our journey:

Due to the need for major additional features and capabilities, especially since the onset of the COVID-19 …

Using EndeavourOS as a daily driver

By Muhammad Najmi bin Ahmad Zabidi
June 16, 2023

Choosing a new distro

I have been using Manjaro Linux (based on Arch Linux) for my work desktop and Pop!_OS (based on Ubuntu) for my laptop for quite some time now, and wanted to find another Arch Linux-based distro for my daily driver. Rather than aimlessly searching through the hundreds of Linux distros out there, I made several requirements the chosen distro should meet:

• Easy to maintain.
• Has strong community support and stable development.
• Has a Linux Unified Key Setup (LUKS) full-disk encryption option in the installation.
• If possible, the distro of choice should be able to trim down the number of default packages. For example, I am a Gnome desktop user, so I don’t want to install the game packages I won’t use.

I decided to use EndeavourOS. It supports the features that I need: It has a strong community and most of Arch Linux’s documentation/​references are still applicable to it, like they are to most Arch Linux-based distros using systemd.

The most notable differences between EndeavourOS and Arch Linux are EndeavourOS’s GUI-based installer—we can select between installing XFCE, Plasma KDE, Gnome, and several others desktop environments—as well as …

Compressed CZML

By Dmitry Kiselev
June 13, 2023

Let’s talk about CZML, Cesium’s main language for specifying 3D scenes, and how to incorporate external resources such as billboard graphics, material textures, and 3D models into CZML files.

For example, let’s look at how we can include glTF models.

glTF models are composed of multiple files: a single JSON index file along with a variable number of binary buffer files and textures. So, in order to package CZML assets that include glTF models for distribution, you have to read the CZML document itself, then read the referenced glTF files. If they are not binary GLB files, you must also read the glTF files and package all of the files referenced by the glTF models. And if you find this paragraph cumbersome, that’s no accident. Indeed, the whole process is quite cumbersome!

So we are dealing with something like:

• CZML Document

  • glTF Model

    • buffer1.bin
    • buffer2.bin
    • texture1.png
    • texture2.png
    • …

If you want to keep the glTF model as a single asset, you can convert the glTF files into binary (GLB) files, and then embed them as base64 data links into CZML.

Another example would be a set of points with billboards, let’s say a couple hundred points with plenty of …