cron.weekly issue #113: .ORG, bpf, sysadvent, php, curl, httpstat & more

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Mattias Geniar, December 08, 2019

Follow me on Twitter as @mattiasgeniar

Hi everyone!

Welcome to the first of many new cron.weekly’s. :-)

I’ve been saving a bunch of links & interesting articles for the past few weeks, this is going to be a big one! If you see any issues in the layout of the mail or if you have any improvements for the content, please let me know.

Enjoy your Sunday!

News & general

The .Org Fire Sale: How it sold for less than half its valuation

In case you missed it, the .ORG top level domain was sold a few weeks ago to a private equity firm. That’s right, the non-profit .ORG TLD will come in private hands. This post looks at what exactly happened and how the price might be way too low.

BPF: A New Type of Software

At Netflix they have 15 BPF programs running on cloud servers by default. These programs are not processes or kernel modules, and don’t appear in traditional observability tools. They are a new type of software, and make a fundamental change to a 50-year old kernel model by introducing a new interface for applications to make kernel requests, alongside syscalls.

How Linus Torvalds accidentally created Linux

Some fun little trivia about where Linux started. A good example of scratch your own itch.

Dear anonymous internet user asking for help …

Bert writes about something many open source maintainers have surely experienced: “Dear anonymous internet user, dear corporate employee hiding behind a address, dear “GitHub account with a single issue”, Thank you for your interest in my free software, my project or the documentation I wrote for you."


It’s that time of the year again! Sysadvent publishes a daily blogpost written by seasoned sysadmins, with the goals of sharing, openness, and mentoring.

Advent of Code 2019

Another yearly tradition in December: Advent of Code gives you a daily coding/puzzle challenge to solve.

Mirantis Acquires Docker Enterprise Platform Business

This is a few weeks old already, but worth noting just in case you missed it: Mirantis announced its acquisition of Docker’s Enterprise Platform business. Wasn’t this once valued at over a billion dollars?

Tools & Projects


Flan Scan is a lightweight network vulnerability scanner by Cloudflare. It’s a wrapper on top of nmap that makes it very easy to work with. It can find open ports on your network, identify services and their version, and get a list of relevant CVEs affecting your network.


Subjack is a Hostile Subdomain Takeover tool written in Go designed to scan a list of subdomains concurrently and identify ones that are able to be hijacked. With Go’s speed and efficiency, this tool really stands out when it comes to mass-testing.

.NET Core 3.1

This is a new LTS release of .NET core, the version of Microsoft’s .NET framework that runs on Linux and Windows.


iodine lets you tunnel IPv4 data through a DNS server. This can be usable in different situations where internet access is firewalled, but DNS queries are allowed.


npq let’s you safely install packages with npm or yarn by auditing them as part of your install process.

Django 3.0

The Django framework has released version 3.0. Some highlights include support for MariaDB 10.1 & higher & async capabilities.


Webhook is a lightweight configurable tool written in Go, that allows you to easily create HTTP endpoints (hooks) on your server, which you can use to execute configured commands.

Home Assistant

I’ve only recently learned about this, but it’s already a few years old with a proven track record. Home Assistant is is home automation that puts local control and privacy first. Perfect to run on a Raspberry Pi or a local server. Home Assistant will track the state of all the devices in your home, so you don’t have to.

PHP 7.4

PHP 7.4 has been released. This new version includes typed properties & short arrow functions, the ability to do opcache preloading & plenty more.

Eternal Terminal

Eternal Terminal (ET) is a remote shell that automatically reconnects without interrupting the session.


httpstat visualizes curl statistics in a way of beauty and clarity.

Guides & Tutorials

Understanding the Hidden Powers of curl

curl is exceedingly powerful - unfortunately, much of this power is somewhat hidden in the purposeful non-verbosity and the underlying complexity of its numerous flags, configurations, and options. This article & video with Daniel Stenberg dives into those options and explains them.

Databases: how they work, and a brief history

How do databases work? This is a very accessible guide that explains the concepts of relational and document-store databases.

libcurl video tutorials

Daniel has started a series of video tutorials on how to write Internet applications using libcurl.

Linux, Where Has my Space Gone?

Most of us know that we should check for open file handles if we’re seeing df report too much diskspace. This post looks at even more places where diskspace can hide if you can’t find the source.

Automatically convert your code to PHP 7.4 syntax using Rector

This post explains how you can use rector to automatically upgrade your code to be compatible with PHP 7.4.

Some Linux network troubleshooting commands

This post contains some of the basic tooling you can use to troubleshoot issues on a Linux server, like telnet, top, grep, …

Linux vs. Unix: What’s the difference?

Dive into the differences between these two operating systems that share much of the same heritage and many of the same goals.

How to monitor MySQL / MariaDB query progress

The progress indicator of MySQL or MariaDB long-running commands and queries can be quite … absent. This post explains a tool called pmonitor to look at the progress of running processes.

Debugging Software Deployments with strace

I think strace is one of my favorite tools on Linux. This post shows how you can use it to debug running applications.

Avoiding dropped connections in nginx containers with “STOPSIGNAL SIGQUIT”

This post debugs an interesting issue with Nginx in Docker containers that abruptly kills connections when a container is restarted, whereas that should happen gracefully.

Asynchronous Zsh prompt with Git status

This is a nice improvement if you’re using zsh to asynchronously fetch the git/svn information. In large repositories, this would otherwise block your shell.

Running containers and OS images with systemd-nspawn

This presentation gives you a very good summary of how to use systemd-nspawn to run containers.

How containers work: overlayfs

This is a comic about overlay filesystems, explaining the concept in easy to understand visuals.

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