Installing Red Hat Container Development Kit on Fedora

Installing Red Hat Container Development Kit on Fedora

Fedora users seeking help on installing Container Development Kit (CDK), here is how you can install CDK 2.2 on your Fedora 24. These same steps can be used for CDK 2.3 too.

CDK provides a container development environment, to build production-grade applications, for use on OpenShift.

The installation of CDK 2.2 on Fedora essentially involves the following stages:

Setting up your virtualization environment
You need to first install the virtualization software, in this case, KVM/libvirt, and then proceed to install Vagrant and its additional plugins to enable the various features of CDK.

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Smart light with Arduino in Fedora / RHEL

The Internet of Things is a very new “thing” to us, but when we think of it, we’ve had access to the internet for a long period of time. We use “things” in day to day life that have been making our life easier for as long as we can remember.

Let’s take a common light bulb as an example. It consumes energy and produces light, which helps us everyday. Technology improvements have stripped down the consumption of resources to a bare minimum, while at the same time optimizing the output; efficiency and function has gone up. We even have internet connected and controllable light bulbs that change colors, operate on timers, and cooperate via mesh networks.

We live in an era where the mobile and telecommunications industries are booming, and the speed of internet would have been un-imaginable just one decade years before. Hence, the idea of making things smarter by connecting them to the internet, analyzing  petabytes of historical and real-time data, and automating their operation becomes more and more a reality. This will result in a smarter way of living, since IoT affects almost all the major areas of the industry: Agriculture, Healthcare, Home Automation, and many more.

This post is a proof of concept of how easy it is to smartly control lights on an Arduino without ethernet shield, but rather over HTTP. The idea is to let you control a single light or series of lights in your house with just a tap of an application (with a proper internet connection of course.)

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Fedora “update testing” with Bodhi

Before and after Fedora releases, there are updates that keep coming in to fix bugs or add minor features to packages included in Fedora. To ensure that these are stable and don’t affect the performance of the existing system, we do “update testing”. Once testing is complete, we share our results and make sure that the developer is aware about the bugs and the success rate of the package. This article will explain how to participate in update testing and contribute to a high quality Fedora release!

(Editor’s note: Fedora is the upstream project for Red Hat Enterprise Linux (RHEL), which is now free for development use.)

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Getting Started with Release Validation Testing in Fedora QA

Release validation testing is a process which takes place before the official Fedora release. (Fedora is the upstream, community project from which RHEL is built.) Before the Final (GA) release, we have Alpha and Beta pre-releases and at each of these milestones, nightly builds (nightlies) and composes are released and tested to ensure that the release meets quality standards. Release validation testing is one way you can help Fedora get better, and this post will talk about how you can start off from scratch.

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Fedora Media Writer – The fastest way to create Live-USB boot media

This post will provide a quick tutorial about Fedora Media Writer, and its usage in both Fedora and Windows. Fedora Media Writer is a very small, lightweight, comprehensive tool that simplifies the linux getting started experience – it downloads and writes your favorite Fedora flavor onto a USB drive, which can be later used to boot up any system.

Editor’s note: This also means you can now create Red Hat Enterprise Linux (RHEL) LiveCDs in just a few minutes. Since RHEL was recently made freely available to all developers, you can download the ISO to use with the Fedora Media Writer.

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Keep it small: a closer look at Docker image sizing

Keep it small: a closer look at Docker image sizing

A recent blog post, 10 things to avoid in docker containers, describes ten scenarios you should avoid when dealing with docker containers. However, recommendation #3 – Don’t create large images and the sentence “Don’t install unnecessary packages or run “updates” (yum update) that download files to a new image layer” has generated quite a few questions.  Some of you are wondering how a simple yum update can create a large image. In an attempt to clarify the point, this post explains how docker images work, some solutions to maintain a small docker image, yet still keep it up to date.

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The ARM Arc Part 3

The ARM Arc Part 3


This week heralded the announcement of Red Hat Enterprise Linux Server for ARM Development Preview 7.1, the next milestone in Red Hat’s exploring the potential for ARM servers.  There is a lot in a name, and this one is a mouthful.

The Linux kernel is famous – it is the namesake of the complete operating system, but it does not exist on its own.  A complete OS runs on hardware, starts out in firmware, loads the kernel, which in turn loads a software and service initialization system, all of which require function libraries, all of which were built with compiler tools that do the magic conversion from human readable source code to machine readable binaries.  When ARM designed the AArch64 architecture, they also had to provide ports and specifications for the firmware, the kernel, the libraries, the compiler, and so on. Hundreds of packages were affected.  Not only did they need to provide ports, those ports needed to be designed, written correctly, in a style acceptable to each of the communities whose coding standards are frequently rigorous, distinct, and strictly enforced.  To top it all off, this work needed to be done before the actual hardware existed, necessitating writing software simulators to check all the work and extensive documentation to empower community collaboration.

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Five different ways to handle leap seconds with NTP

A leap second is an adjustment that is once in a while applied to the Coordinated Universal Time (UTC) to keep it close to the mean solar time. The concept is similar to that of leap day, but instead of adding a 29th day to February to keep the calendar synchronized with Earth’s orbit around the Sun, an extra second 23:59:60 is added to the last day of June or December to keep the time of the day synchronized with the Earth’s rotation relative to the Sun. The mean solar day is about 2 milliseconds longer than 24 hours and in long term it’s getting longer as the Moon is constantly slowing down the Earth’s rotation.

UTC is based on the International Atomic Time (TAI) and it is currently 35 seconds behind TAI. The first leap second was inserted in 1972 and 25 seconds were inserted so far. The next one is scheduled for 30 June 2015, when the offset from TAI will increase to 36 seconds. Leap seconds are scheduled only about 6 months in advance.

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The ARM Arc Part 2

This is a continuation to The ARM Arc Part 1 published in July.

ARM_LogoIt all started in 2012 when the Fedora ARM community decided to move from the legacy ARMv5 software floating point ABI to the new ARMv7 hard float ABI.  The move meant better performing code, native atomic operations, threading support, and other modern OS features becoming available to ARM software developers on a general purpose OS.  Doing the work required a way to bootstrap a new architecture, which is notoriously difficult due to Fedora’s inter-dependent package structure.  When building package A depends on having package B, and building package B depends on having package A, and you have 15000 such packages, it poses an epic challenge.

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