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Kubernetes (build: k3s-c9s-250718)

Description

Lightweight Kubernetes cluster based on the K3S distribution and CentOS 9 Stream as a base OS. K3s is a fully compliant Kubernetes distribution with the following enhancements:

  • Distributed as a single binary or a minimal container image.
  • Lightweight datastore based on etcd3.
  • Wrapped in a simple launcher that handles a lot of the complexity of TLS and options.
  • Secure by default with reasonable defaults for lightweight environments.
  • Operation of all Kubernetes control plane components is encapsulated in a single binary and process, allowing K3s to automate and manage complex cluster operations like distributing certificates.
  • External dependencies have been minimized; the only requirements are a modern kernel and cgroup mounts.
  • Packages the required dependencies for easy "batteries-included" cluster creation:

    • containerd / cri-dockerd container runtime (CRI)
    • Flannel Container Network Interface (CNI)
    • CoreDNS Cluster DNS
    • Traefik Ingress controller
    • ServiceLB Load-Balancer controller
    • Kube-router Network Policy controller
    • Longhorn Persistent Volume controller
    • Spegel distributed container image registry mirror

Features

Parameter Value
Operating System CentOS Stream
OS Release CentOS Stream 9
Desktop Environment -
License GPLv2, Apache 2.0 (Free and open-source)
Processor 1 CPU
RAM 1 GiB
Swap 1 GiB
System Disk 30 GiB
User Account admin
User Password Options: temporary password (sent by email); set own password
Network Interfaces eth0 managed by NetworkManager
Initialization System cloud-init
Virtualization oVirt
Updates 2025-07-14

Disk Partitioning

Partition Table: GPT

Filesystem / (xfs) auto-resizes to the provisioned system disk size.

Type Name Size, GiB File System Description
Partition sda1 0.58 vfat EFI
Partition sda2 0.94 xfs /boot
Partition sda3 8.4 - LVM PV
Partition sdb User input - LVM PV
LV cs-root 7.4 xfs root
LV cs-swap 1 swap Swap
LV data-longhorn User input xfs /var/lib/longhorn

Configuration

OS firewall is disabled. Use the app Networking > SecurityGroups instead.

Installed software

  • qemu-guest-agent
  • cockpit
  • python3-pip
  • iscsi-initiator-utils
  • kubectl
  • helm
  • k3s
  • nfs-tools

License

CentOS Stream: Free and open-source: GPLv2. Paid licenses and subscriptions are not required.

K3S: Free and opensource: Apache 2.0 Paid licenses and subscriptions are not required.