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Kubernetes: KubeInvaders, CSI Ephemeral Inline Volumes and Reviewing 2019 in Docs

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  • KubeInvaders - Gamified Chaos Engineering Tool for Kubernetes

    Some months ago, I released my latest project called KubeInvaders. The first time I shared it with the community was during an Openshift Commons Briefing session. Kubenvaders is a Gamified Chaos Engineering tool for Kubernetes and Openshift and helps test how resilient your Kubernetes cluster is, in a fun way.

  • CSI Ephemeral Inline Volumes

    Typically, volumes provided by an external storage driver in Kubernetes are persistent, with a lifecycle that is completely independent of pods or (as a special case) loosely coupled to the first pod which uses a volume (late binding mode). The mechanism for requesting and defining such volumes in Kubernetes are Persistent Volume Claim (PVC) and Persistent Volume (PV) objects. Originally, volumes that are backed by a Container Storage Interface (CSI) driver could only be used via this PVC/PV mechanism.

    But there are also use cases for data volumes whose content and lifecycle is tied to a pod. For example, a driver might populate a volume with dynamically created secrets that are specific to the application running in the pod. Such volumes need to be created together with a pod and can be deleted as part of pod termination (ephemeral). They get defined as part of the pod spec (inline).

    Since Kubernetes 1.15, CSI drivers can also be used for such ephemeral inline volumes. The CSIInlineVolume feature gate had to be set to enable it in 1.15 because support was still in alpha state. In 1.16, the feature reached beta state, which typically means that it is enabled in clusters by default.

    CSI drivers have to be adapted to support this because although two existing CSI gRPC calls are used (NodePublishVolume and NodeUnpublishVolume), the way how they are used is different and not covered by the CSI spec: for ephemeral volumes, only NodePublishVolume is invoked by kubelet when asking the CSI driver for a volume. All other calls (like CreateVolume, NodeStageVolume, etc.) are skipped. The volume parameters are provided in the pod spec and from there copied into the NodePublishVolumeRequest.volume_context field. There are currently no standardized parameters; even common ones like size must be provided in a format that is defined by the CSI driver. Likewise, only NodeUnpublishVolume gets called after the pod has terminated and the volume needs to be removed.

  • Reviewing 2019 in Docs

    Hi, folks! I’m one of the co-chairs for the Kubernetes documentation special interest group (SIG Docs). This blog post is a review of SIG Docs in 2019. Our contributors did amazing work last year, and I want to highlight their successes.

    Although I review 2019 in this post, my goal is to point forward to 2020. I observe some trends in SIG Docs–some good, others troubling. I want to raise visibility before those challenges increase in severity.

More in Tux Machines

Evince chosen as the Librem 5 Document Viewer

The default Librem 5 applications define the out of the box experience. Our team has been hard at work adding essential apps that people expect from a smartphone. The latest is the popular FOSS document viewer Evince which we adapted using our powerful convergence library libhandy. We have put a lot of design and development into the idea of convergence – the ability to run applications on desktop and mobile without maintaining separate code basess or many additional views. libhandy has already been successfully used to adpat or build all the current Librem 5 apps including GNOME Settings, Epiphany, Calls, Chats and more. What makes libhandy so powerful for designers and developers is its simplicity. Just swap out your widget inheritance to use libhandy and add breakpoint logic. Read more

GNU/Linux in Devices

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    – Control: GNU Radio support

  • 3D-printable Raspberry Pi bits and pieces you should totally make

    Recently, we’ve seen an awful lot of new designs online for 3D-printable Raspberry Pi cases and add-ons. Here are a few that definitely need your attention.

  • Best USB Gaming Controllers With Linux Support (Review) in 2020 [Ed: The links appear to be Amazon 'referral spam']

    Are you looking to get a new gaming controller for your Linux PC? Not sure which one to buy so that you don’t run into any issues? We can help, because we’ve done the research for you and our in-depth analysis can reveal which is the best product for the buck. Here’s our list with the top USB gaming controllers for Linux.

  • Best USB WiFi Adapters for Linux (Review) in 2020

    It is hard to find a Linux-compatible USB WiFi adapter these days, as mainstream manufacturers like Netgear, Belkin, and others do not take the platform seriously. As a result, many Linux users do not know what to buy. Since finding a compatible Linux WiFi adapter is so tricky we researched more than 20 models on the market — read more about our in-depth analysis and see which is the best product. Here’s our list of the best Linux compatible USB WiFi adapters.

Audiocasts/Shows: Linux in the Ham Shack and More

  • LHS Episode #326: Ni Hao, Moto

    Hello and welcome to the 326th installment of Linux in the Ham Shack. In this short-topic format show, the hosts discuss a major win for Motorola, the FCC and 5.9GHz, operating practices in Australia, iText, FreshRSS, GridTracker and much more. Thank you for listening and please, if you can, donate to our Hamvention 2020 Fund.

  • Ask Lunduke - Feb 17, 2020 - Slackware and Pre-Internet Podcasts

    Ask Lunduke is a weekly podcast where the community can ask any question they like… and I (attempt to) answer them. This episode is available via Podcast RSS feed, LBRY, Patreon, and YouTube. Links on the left. Topics on Ask Lunduke this week: Why does closed source software exist? How can we fix WHOIS? Would a Star Trek Land be more popular than Disney's Star Wars Land?

  • Another Look at My Homelab (More Detail)

    You asked for more detail on my Homelab, so here it is. In this video, I go over a bit more detail on how my Homelab is organized, so you can get an idea on how everything is connected together.

Red Hat OpenShift, Satellite and Latest Brag

  • OpenShift 4.3: Console Customization: YAML Samples

    Out of the box, OpenShift 4 provides a few examples for users. With this new extension mechanism users can now add their own YAML sample for all users on the Cluster. Let us look at how we can manually add a YAML example to the cluster. First we need to navigate to the Custom Resource Definition navigation item and search for YAML:

  • Red Hat Satellite Ask Me Anything Q&A from January 15, 2020

    This post covers the questions and answers during the January 2020 Satellite Ask Me Anything (AMA) calls. For anyone not familiar, the Satellite AMAs are an "ask me anything" (AMA) style event where we invite Red Hat customers to bring all of their questions about Red Hat Satellite, drop them in the chat, and members of the Satellite product team answers as many of them live as we can during the AMA and we then follow up with a blog post detailing the questions and answers.

  • Red Hat named to Fortune’s 100 Best Companies to Work For list for 2nd year in a row

    If you ask Red Hatters why they love working for Red Hat, you’ll hear a common theme. The culture and the people. I frequently hear from new Red Hatters that it just feels different to work here. It’s clear our associates are passionate about being apart of something bigger than themselves, a movement. As a result, Red Hat has been ranked No. 48 on Fortune Magazine's list of 100 Best Companies to Work For! This is our second consecutive year making the list and it’s most gratifying that in a year full of exciting change, one thing has remained constant. Red Hat is still Red Hat and it is a great place to work! Thinking back on this year and all that we’ve experienced, I’m grateful that we have put a great deal of attention and focus on continuing Red Hat’s culture because of the value it brings to our associates, customers, partners and the industry as a whole. We are all committed to preserving our way of working and this latest recognition is a testament to this effort. As we move forward, we are laser focused on maintaining what we do and how we do it—the open source way.