Managing Clusters on Flatcar Container Linux

Cluster Architectures

Mon, 01 Jan 0001 00:00:00 +0000

Overview

Depending on the size and expected use of your Flatcar Container Linux cluster, you will have different architectural requirements. A few of the common cluster architectures, as well as their strengths and weaknesses, are described below.

Most of these scenarios dedicate a few machines, bare metal or virtual, to running central cluster services. These may include etcd and the distributed controllers for applications like Kubernetes, Mesos, and OpenStack. Isolating these services onto a few known machines helps to ensure they are distributed across cabinets or availability zones. It also helps in setting up static networking to allow for easy bootstrapping. This architecture helps to resolve concerns about relying on a discovery service.

Cluster discovery

Mon, 01 Jan 0001 00:00:00 +0000

Overview

Flatcar Container Linux uses etcd, a service running on each machine, to handle coordination between software running on the cluster. For a group of Flatcar Container Linux machines to form a cluster, their etcd instances need to be connected.

A discovery service, https://discovery.etcd.io , is provided as a free service to help connect etcd instances together by storing a list of peer addresses, metadata and the initial size of the cluster under a unique address, known as the discovery URL. You can generate them very easily:

Running Flatcar Container Linux with AWS EC2 Container Service

Mon, 01 Jan 0001 00:00:00 +0000

Amazon EC2 Container Service (ECS) is a container management service which provides a set of APIs for scheduling container workloads across EC2 clusters. It supports Flatcar Container Linux with Docker containers.

Your Flatcar Container Linux machines communicate with ECS via an agent. The agent interacts with Docker to start new containers and gather information about running containers.

Set up a new cluster

When booting your Flatcar Container Linux Machines on EC2 , configure the ECS agent to be started via Ignition .