ansible-role-k3s/README.md

9.8 KiB

Ansible Role: k3s

Ansible role for installing Racher Labs k3s ("Lightweight Kubernetes") as either a standalone server or cluster.

Build Status

Requirements

The control host requires the following Python dependencies:

  • jmespath >= 0.9.0

This role has been tested on Ansible 2.7.0+ against the following Linux Distributions:

  • Amazon Linux 2
  • CentOS 8
  • CentOS 7
  • Debian 9
  • Debian 10
  • Fedora 29
  • Fedora 30
  • Fedora 31
  • openSUSE Leap 15
  • Ubuntu 18.04 LTS

Disclaimer

⚠️ May not be suitable for production use!

Rancher Labs is awesome and has released k3s as v1.0.0, however at the time of creating this role I do not have a k3s cluster in production nor am I unlikely to ever have one. Please ensure you practice extreme caution and operational rigor before using this role for any serious workloads.

If you have any problems please create a GitHub issue, I maintain this role in my spare time so I cannot promise a speedy fix delivery.

Role Variables

Group Variables

Below are variables that are set against all of the play hosts for environment consistency.

Variable Description Default Value
k3s_cluster_state State of cluster: installed, started, stopped, restarted, downloaded. installed
k3s_release_version Use a specific version of k3s, eg. v0.2.0. Specify false for latest. false
k3s_github_url Set the GitHub URL to install k3s from. https://github.com/rancher/k3s
k3s_install_dir Installation directory for k3s. /usr/local/bin
k3s_use_experimental Allow the use of experimental features in k3s. false
k3s_non_root Install k3s as non-root user. See notes below. false
k3s_control_workers Are control hosts also workers? true
k3s_cluster_cidr Network CIDR to use for pod IPs 10.42.0.0/16
k3s_service_cidr Network CIDR to use for service IPs 10.43.0.0/16
k3s_control_node_address Use a specific control node address. IP or FQDN. NULL
k3s_control_token Use a specific control token, please read notes below. NULL
k3s_https_port HTTPS port listening port. 6443
k3s_use_docker Use Docker rather than Containerd? false
k3s_no_flannel Do not use Flannel false
k3s_flannel_backend Flannel backend ('none', 'vxlan', 'ipsec', or 'wireguard') vxlan
k3s_no_coredns Do not use CoreDNS false
k3s_cluster_dns Cluster IP for CoreDNS service. Should be in your service-cidr range. NULL
k3s_cluster_domain Cluster Domain. cluster.local
k3s_resolv_conf Kubelet resolv.conf file NULL
k3s_no_traefik Do not use Traefik false
k3s_no_servicelb Do not use ServiceLB, necessary for using something like MetalLB. false
k3s_no_local_storage Do not use Local Storage false
k3s_no_metrics_server Do not deploy metrics server false
k3s_disable_scheduler Disable Kubernetes default scheduler false
k3s_disable_cloud_controller Disable k3s default cloud controller manager. false
k3s_disable_network_policy Disable k3s default network policy controller. false
k3s_write_kubeconfig_mode Define the file mode from the generated KubeConfig, eg. 644 NULL

Important note about k3s_release_version

If you do not set a k3s_release_version the latest version of k3s will be installed. If you are developing against a specific version of k3s you must ensure this is set in your Ansible configuration, eg:

k3s_release_version: v0.2.0

Important note about k3s_non_root

To install k3s as non root you must not use become: true. The intention of this variable is to run a single node development environment. At the time of release v1.0.1, rootless is still experimental.

You must also ensure that you set k3s_use_experimental to true.

Additionally k3s_install_dir must be writable by your user.

Important notes about k3s_control_node_address and k3s_control_token

If you set this, you are explicitly specifying the control host that agents should connect to, the value should be an IP address or FQDN.

If the control host is not configured by this role, then you need to also specify the k3s_control_token.

Please note that this may potentially break setting up agents.

Host Variables

Below are variables that are set against specific hosts in your inventory.

Variable Description Default Value
k3s_control_node Define the host as a control plane node, (True/False). false
k3s_node_name Define the name of this node. $(hostname)
k3s_node_id Define the ID of this node. NULL
k3s_flannel_interface Define the flannel proxy interface for this node. NULL
k3s_bind_address Define the bind address for this node. localhost
k3s_node_ip_address IP Address to advertise for this node. NULL
k3s_node_external_address External IP Address to advertise for this node. NULL
k3s_node_labels List of node labels. NULL
k3s_node_taints List of node taints. NULL
k3s_node_data_dir Folder to hold state. /var/lib/rancher/k3s
k3s_tls_san Add additional hosname or IP as Subject Alternate Name in the TLS cert. NULL
k3s_server_manifests_dir Path for place the k3s_server_manifests_templates. /var/lib/rancher/k3s/server/manifests
k3s_server_manifests_templates A list of Auto-Deploying Manifests Templates. []

Important note about k3s_control_node

Currently only one host can be defined as a control node, if multiple hosts are set to true the play will fail.

If you do not set a host as a control node, the role will automatically delegate the first play host as a control node.

Important note about k3s_flannel_interface

If you are running k3s on systems with multiple network interfaces, it is necessary to have the flannel interface on a network interface that is routable to the master node(s).

Notes about k3s_node_labels and k3s_node_taints

Both these variables are lists that will be iterated on. The below example will output the following:

YAML:

k3s_node_labels:
  - foo: bar
  - hello: world

k3s_node_taints:
  - key1: value1:NoExecute

ARGS:

--node-label foo=bar \
--node-label hello=world \
--node-taint key1=value1:NoExecute

Dependencies

No dependencies on other roles.

Example Playbook

Example playbook:

- hosts: k3s_nodes
  roles:
     - { role: xanmanning.k3s, k3s_release_version: v0.10.2 }

License

BSD

Author Information

Xan Manning