Kubernetes (K8S) Cluster on AlmaLinux 8 with Containerd Container Runtime
This article show how to install Kubernetes (K8S) cluster on AlmaLinux 8 with Containerd Container Runtime.
CentOS Stream is an upstream development platform designed for CentOS community members, Red Hat partners, ecosystem developers, and many other groups to more quickly and easily see what’s coming in the next version of Red Hat Enterprise Linux (RHEL) and to help shape these capabilities. Since its introduction in 2019, we’ve seen great enthusiasm from partners and contributors around CentOS Stream and the continuous stream of innovation that the project provides.
Containerd - An industry-standard container runtime with an emphasis on simplicity, robustness, and portability.
containerd is available as a daemon for Linux and Windows. It manages the complete container lifecycle of its host system, from image transfer and storage to container execution and supervision to low-level storage to network attachments and beyond.
Kubespray allows you to deploy a production-ready Kubernetes cluster (using Ansible or Vagrant) and since v2.3 can work together with Kubernetes kubeadm.
Ansible is the simplest way to automate apps and IT infrastructure. Application Deployment + Configuration Management + Continuous Delivery.
CentOS 8 / Oracle Linux 8 / AlmaLinux 8 and derivatives
CentOS 8 / Oracle Linux 8 / AlmaLinux 8 ship only with iptables-nft (ie without iptables-legacy similar to RHEL8) The only tested configuration for now is using Calico CNI You need to add
calico_iptables_backend: "NFT" or
calico_iptables_backend: "Auto" to your configuration.
If you have containers that are using iptables in the host network namespace (
hostNetwork=true), you need to ensure they are using
iptables-nft. An example how k8s do the autodetection can be found in this PR update images to Debian buster, detect iptables mode by danwinship · Pull Request #82966 · kubernetes/kubernetes - https://kubespray.io/#:~:text=can%20be%20found-,in%20this%20PR
See CentOS/OracleLinux/AlmaLinux - https://kubespray.io/#/docs/centos8 to learn more.
You have two ways to run Kubespray.