You may still have some bare metal servers lying around, freed by the heavy use of public clouds. But don’t throw them away yet, tooling exist to offer almost as much agility as virtual machine provisionning. Tools like Foreman, Cobbler, Razor, MAAS or OpenStack Ironic fills that gap. Today we’ll look at matchbox from CoreOS, it has a pretty name now, it used to be called coreos-baremetal and bootcfg. matchbox offers a HTTP and gRPC service which will help to easily build out CoreOS clusters out of your servers.
Evolution is drastic in IT, we now see applications running in containers, public clouds eating the world with self-service offerings. The world of computing has to adapt and provide a foundation for this constant innovation. This is exaclty what the CoreOS team have been doing for almost four years. It all started with CoreOS a minimalistic Linux operating system which have recently been renamed Container Linux, which gives a quick overview of what it is built for. It’s only purpose is to be a foundation layer to run your containerized and distributed cloud-native application. Having such a reduced footprint makes it way more secure, it was the driving force behind it. Also by reducing the adherence between your application and the infrastructure operating system, updates becomes way easier, so your environment will be kept secured. Container Linux offer a minimum set of binaries, mostly systemd, etcd, rkt and flannel for networking. Anything else can run as containers on top of Container Linux.
Containers are taking the IT world by storm, instead of re-inventing the wheel, CoreOS wants to offer the next-generation open source app container runtime, designed for security, simplicity and composability. But above all, they want to play fair with the ecosystem by ensuring it is built on common open standards and use what’s readily available like systemd and Kubernetes.
rkt is written in Go, it compile to a single static binary, so it is easily portable to any modern system, for the rest read on.
Kargo (a.k.a Kubespray) is an initiative to deploy a Kubernetes cluster using Ansible. It will contrast with our previous Step by Step article by showing that we can deploy a cluster with a single command, a bit like the newly integrated SwarmKit feature announced in Docker 1.12
docker swarm init.
Tectonic from CoreOS is an enterprise-grade Kubernetes solution which simplifies management operation of a k8s environment by leveraging CoreOS, fleet, Rkt and Flannel. In this article we’ll manually build a cluster of three CoreOS nodes on top of VMware Fusion to see how all of this fits together.