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Description

Ansible role for managing rancher k3s, lightweight, cncf-certified kubernetes distribution.
This role can be used to install simple single-node or multi-master HA clusters.
It can be used to manage multiple k3s clusters in single ansible inventory.
It's also heavily customizable for almost any purpose - you can edit pretty much any k3s setting.
It can install gvisor, additional host dependencies, load specific kernel modules, adjust k3s-related sysctl settings and so on.

Documentation

Detailed docs are available here

Requirements

Apart from what k3s requires, this role also needs systemd, so it should work on any modern distro.

Variables

Variable name Default value Description
k3s_version v1.29.1+k3s1 version of k3s to install
k3s_systemd_dir /etc/systemd/system Directory for systemd unit file
k3s_master false installs k3s master when true
k3s_agent false installs k3s agent when true
k3s_master_ip first node in k3s_master_group group ip/hostname of master node
k3s_master_port 6443 port of masterserver
k3s_install_mode online k3s install mode - online or airgap
k3s_flannel_backend vxlan k3s flannel backend to use. Set to none to disable flannel
k3s_master_disable [] array of k3s packaged components to disable (traefik,metrics-server,etc)
k3s_master_extra_args [] extra arguments for k3s server (official docs)
k3s_master_extra_config `` YAML with extra config for k3s master
k3s_agent_extra_config `` YAML with extra config for k3s agent
k3s_kubelet_extra_config `` Additional arguments for kubelet, see docs
k3s_agent_extra_args [] extra arguments for k3s agent (official docs)
k3s_extra_config_files {} extra configfiles for k3s
k3s_bpffs false mounts /sys/fs/bpf bpffs (needed by some network stacks)
k3s_external_ip `` specifies k3s external ip
k3s_internal_ip `` specifies k3s node ip
k3s_registries `` Configures custom registries, see official docs for format
k3s_cronjob_prune_images absent Configures cronjob that prunes unused images in containerd daily. Either absent or present
k3s_gvisor false Installs gvisor
k3s_gvisor_version 20231218 gvisor version to install
k3s_gvisor_platform systrap Selects platform to use in gvisor
k3s_gvisor_config `` Sets additional options for gvisor runsc. See notes
k3s_gvisor_create_runtimeclass true Automatically create gvisor RuntimeClass in kubernetes
k3s_kubeconfig false Downloads kubeconfig to machine from which role was launched
k3s_kubeconfig_server see below specifies server for use in kubeconfig
k3s_kubeconfig_context k3s specifies context to use in kubeconfig
k3s_kubeconfig_target: {{ k3s_kubeconfig_context }} specifies filename for downloading kubeconfig
k3s_agent_group k3s_node specifies ansible group name for k3s nodes
k3s_master_group k3s_master specifies ansible group name for k3s master(s)
k3s_extra_packages [] Installs additional packages if needed by workloads (ie iscsid)
k3s_extra_services [] Enables additional services if needed by workloads (ie iscsid)
k3s_extra_config_files {} additional config files for kubelet/kubeapi
k3s_sysctl_config {} Allows setting arbitrary sysctl settings
k3s_extra_manifests {} Allows applying kubernetes manifests

Changelog

Changelog is available in separate file

Tests

This role is continiously tested via ansible-molecule with github actions in on Ubuntu 22.04 and Rocky Linux 8 in different scenarios, including:

  • single-node install
  • single-node install with customized config
  • single-node airgapped install
  • cluster install (3 masters, 1 node)

Other ansible roles to check out

If you got interested in that role, you might want to check out others that go nicely with my k3s one: