cron.weekly issue #153: Kernel 5.9, Julia, NPM, Waypoint & more

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Mattias Geniar, October 18, 2020

Follow me on Twitter as @mattiasgeniar

Hi everyone! 👋

Welcome to cron.weekly issue #153.

Lots of good stuff again this week!

Grab that ☕️ and enjoy folks.

News & general 🗞

Kernel 5.9

Linus has released the 5.9 kernel. Here are some notable changes:

  • Support for new AMD RDNA 2 graphics cards
  • Support for Intel FSGSBASE, which could speed up existing Intel CPU’s (very welcome after all the performance impacts from last years’ vulnerabilities, I can imagine)
  • Various file-system improvements (ie: Btrfs, XFS & F2FS)

As usual, Kernel Newbies has a full overview of the new 5.9 changes. Phoronix shared some interesting stats about the size of AMD’s code, relative to the other areas of the kernel.

Amazon bought 4M extra IPv4 addresses

Amazon spent $108 million in 2019 to buy the range, roughly 4 million IPs. The deal took place last year, but we’re only now learning they paid a whopping $27 per IPv4 address. 🤯

Tools & Projects 🛠

LLVM 11.0

A new major release of LLVM, the compiler infrastructure. Most of these changes are so low-level, they go above my knowledge skill. I’m sure developers will appreciate the new release. 😄

Automatically collect, visualize, and alert on PostgreSQL data

Ensure the health and performance of your databases with Datadog. Correlate metrics from your PostgreSQL servers with other services within your environment by using Datadog’s 400+ vendor-backed integrations.

Start a free trial today, install the agent, and Datadog will send you a free t-shirt! Sponsored


FreePN is a new open-source peer-to-peer VPN service.

HashiCorp Boundary

A new tool from the open-source factory that is called HashiCorp(*): Boundary enables identity-based access management for dynamic infrastructure. It enables practitioners and operators to securely access dynamic hosts and services with fine-grained authorization without requiring direct network access.

(*) I mean this in a positive sense. 😄

HashiCorp Waypoint

A new open-source project that provides developers a consistent workflow to build, deploy, and release applications across any platform.

Webpack 5

A new release of Webpack, featuring several breaking changes from version 4. This will mostly affect front-end devs, but it looks like you’ll have to change some configs to make v5 work.

npm v7

A new major version of Node’s package manager, npm.

JuliaMono Font

A monospaced typeface designed for programmers. It supports a wide range of specialist and technical Unicode characters. Looks pretty good to me!


Cursus stores your shell history and makes it searchable. You’ll find more examples/origin details in this blogpost.


Gitjacker downloads git repositories and extracts their contents from sites where the .git directory has been mistakenly uploaded.

Xonsh Shell

Xonsh is Python with added shell syntax thrown in. You probably already know Python, and so xonsh allows you to run command-line applications without needing to learn a new, arcane syntax whenever you want to use a for-statement.


OptaPlanner is an AI constraint solver. It optimizes planning and scheduling problems, such as the Vehicle Routing Problem, Employee Rostering, Maintenance Scheduling, Task Assignment, School Timetabling, Cloud Optimization, Conference Scheduling, Job Shop Scheduling, Bin Packing and many more.


ParaTest adds support for parallel testing in PHPUnit. Provided you have well-written PHPUnit tests, you can drop paratest in your project and start using it with no additional bootstrap or configurations.


Bit is a modern Git CLI. With auto-completion and command/flag suggestions, it could make git a lot more user-friendly.

Oh my Posh 3

Oh my Posh enables you to use the full color set of your terminal by using hex colors to define and render the prompt. It’s a cross-platform, highly customizable and extensible prompt theme engine.

Guides & Tutorials 🎓

SSH defaults, config, and priorities

If you’ve ever wanted to clean up your local ~/.ssh/config, this post contains some good gotcha’s on the priority in which the config file is read & interpreted.

Tracking Running Processes on Linux

There are so many pitfalls to trying to track processes on a Linux server, this guide covers pretty much all of them.

40 milliseconds of latency that just would not go away

An interesting read on Nagle algorithm. I remember discussions around this in the office (back when, you know, actually went to offices). In order to make TCP more “efficient”, the network stack can decide to queue several TCP packets and try to send them all at once, to avoid any TCP header overhead. However, that’s not always your desired outcome, if you want to get packets out the door ASAP.

Dockerfile Security Best Practices

Container security is a broad problem space and there are many low hanging fruits one can harvest to mitigate risks. A good starting point is to follow some rules when writing Dockerfiles. This post contains a list of common security issues and how to avoid them.

Running Falco and k3s at the edge with 64-bit ARM

This guide covers getting started with Falco (detecting security threats) and k3s (a lightweight Kubernetes).

Why the Unix newgrp command exists (sort of)

Did you know that #Unix groups have passwords? Apparently if you set one, you then have to use newgrp to log in to that group.

This post explains the Unix background behind the newgrp command.

Jobs 📇

If you want to advertise your job opening here, have a look at the sponsorship section on the website and get in touch.

Reliability Engineer at ECMWF

You will be joining a team that is responsible for ensuring that ECMWF and community-developed applications operate reliably and with good performance on our infrastructure. This will involve engaging with, advising, steering and supporting all functions involved in the lifecycle of application deployment and hosting. Your tech stack will include Ansible & Puppet and you’ll work cloud-native.

Location: Reading, Berkshire, UK

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