Philippe Pepiot

DNS expert

Migrate kubernetes kubeadm clusters from docker to cri-o runtime

As you may known, kubernetes is deprecating docker as container runtime, the deprecation will be effective for 1.23 in late 2021. I maintain some production clusters (single & multi nodes) running on debian buster and managed with kubeadm. Here’s how I migrated them from docker to cri-o. Disclaimer: test this on a staging cluster, learn cri-o basics and backup before doing this on production! My clusters were running on kubernetes 1. Read More…

May 5, 2020

Manage debian VMs on LVM with cloud-init

My daily work include managing Debian virtual machines on bare-metal servers. I only use stable CLI tools available in Debian: obviously qemu/kvm lvm volumes, thinly provisioned. libvirt provide CLI utilities to run multiple VMs. hugepages a virtual network bridge and a dhcp server, either dnsmasq or isc-dhcp-server, with static leases The installation of a new VM should be fully automated, i.e. not using the Debian installer. I used to have my own scripts to create a new VM disk on LVM volume, it was based on grml-debootstrap and some xml templates. Read More…

June 17, 2019

Single disk to raid1 with LVM on Debian stretch

Recently, I remembered that I have a second disk on my server and missed to use it when installing the system… So I decided to migrate to raid 1 on a single LVM volume group. The best guide I found was, like often, on the ArchLinux wiki. Here’s my guide for Debian stretch. First create a partition on the second disk using fdisk and make it bootable: % fdisk /dev/sdb Welcome to fdisk (util-linux 2. Read More…

May 13, 2019

Kubernetes the self-hosted single node way

For more than ten years, I have a self-hosted server providing common services including mail, dns and http. One of the first architecture of the server was amazing because it was a FreeBSD server with jails on top of zfs. It was the same idea than cgroups, docker and overlayfs before they even exists ! This setup was very fun to maintain, but I had less time to do it, so in 2012 I switched the server to Debian GNU/Linux first with LXC and then to qemu/kvm. Read More…

August 20, 2018

A Makefile for your dockerfiles

I have a git repository containing multiples Dockerfile for images I use in my Kubernetes cluster and I wanted to have a simple way to build, rebuild, run, test and push my images without needing to type weird docker invocations. Also my requirements for the build system where: Able to handle dependencies: if image B depends on image A, build A first. Able to parallelize build when possible: two independent images can be built concurrently Able to rebuild image with --no-cache when packages updates are available. Read More…