Posts

Showing posts from 2017

Making minimal graphical operating system

Image
Back in my first days of Linux I had a bootable floppy disk with fully functional Linux distro (a kernel, a shell and busybox tools and lua scripting). Maybe that was not much, but it was less than 2MB and would work on an old 386 PC with 4MB of RAM. But shell is boring, graphical minimal Linux distros was several hundreds of mega bytes and need hundreds of MB of RAM.

Embedded devices typically have a minimal Linux with busybox or alike running with no graphical interface but instead they have some sort of web interface exposed to some port.

If you tried to run a minimal graphical Linux distro let's say XFCE on an embedded device (let's say a raspberry pi) you would notice that most of its limited resources are taken by Xorg the legacy graphical server.

Introducing Wayland Wayland is a new different approach to graphical interface, instead of sending drawing instruction over a legacy protocol (with so many extensions) to a legacy daemon (with so many extensions) that most of …

Summary of kubernetes features and terminologies

Image
Introduction Kubernetes had won the container orchestration war. Here is a summary of its features. It's an API, command line and UI. It uses etcd to keep its state. Every thing is done via Yaml or JSON (your choice). GeneralNode: a machine or instance (used to be called "minion")Namespace: a grouping of resourcesLabel: a tag applied to a resource ex. role=frontendAnnotations: another form of meta data  WorkloadsContainer (spec): the building block of deployable service or runnable task using linux containers ex. docker image and params to pass at runtime. Typically created in a Pod see belowPod (spec): one of more containers scheduled to nodes together and thus can share volumes. Most common pods have a single container but there are use cases for more (ex. nginx and php-fpm) . If you replicate a pod to have 3 replicas it would have 3 nginx and 3 php-fpm. If php-fpm created a file in the volume, nginx can see it. Typically created on its own or by controllers like a Re…

Bootstrapping Alpine Linux QCow2 image

IntroductionAlpine Linux is a minimal distro with package manager (APK) that is based on busybox and musl library. Like the CirrOS, it's very lightweight, but unlike it, it's full featured. In case you don't know me, my Linux distro of choice is Fedora/CentOS, in this post I'm going to bootstrap a QCow2 cloud image of Alpine Linux on my distro of choice.


Using docker to bootstrap a working chroot Type mkdir alpine35-root docker run --rm -ti -v $PWD/alpine35-root:/data alpine:3.5 apk --arch x86_64 -X http://nl.alpinelinux.org/alpine/v3.5/main/ -U --allow-untrusted --root /data --initdb add alpine-base 
and you should get a line like this
OK: 6 MiB in 16 packages
so now we have a working alpine chroot in the directory alpine35-root
Creating Bootable QCoW2 Image Because I don't want to format my hard disk by mistake and because I know Murphy's law, I'll take those 6MB as tarball and continue on a VM.
dd if=/dev/zero of=alpine.raw bs=1M seek=511 count=1 dd if=…