109 lines
3.0 KiB
Markdown
109 lines
3.0 KiB
Markdown
# Build a Kubernetes cluster using K3s via Ansible
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Author: <https://github.com/itwars>
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Current Maintainer: <https://github.com/dereknola>
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Easily bring up a cluster on machines running:
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- [X] Debian
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- [X] Ubuntu
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- [X] Raspberry Pi OS
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- [X] RHEL Family (CentOS, Redhat, Rocky Linux...)
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- [X] SUSE Family (SLES, OpenSUSE Leap, Tumbleweed...)
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- [X] ArchLinux
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on processor architectures:
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- [X] x64
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- [X] arm64
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- [X] armhf
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## System requirements
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The control node must have Ansible 2.10.0+
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All managed nodes in inventory must have:
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- Passwordless SSH access
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- Root access (or a user with equivalent permissions)
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It is also recommended that all managed nodes disable firewalls and swap. See [K3s Requirements](https://docs.k3s.io/installation/requirements) for more information.
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## Usage
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First copy the sample inventory to `inventory.yml`.
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```bash
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cp inventory-sample.yml inventory.yml
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```
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Second edit the inventory file to match your cluster setup. For example:
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```bash
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k3s_cluster:
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children:
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server:
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hosts:
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192.16.35.11
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agent:
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hosts:
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192.16.35.12
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192.16.35.13
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```
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If needed, you can also edit `vars` section at the bottom to match your environment.
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If multiple hosts are in the server group the playbook will automatically setup k3s in HA mode with embedded etcd.
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An odd number of server nodes is required (3,5,7). Read the offical documentation below for more information and options.
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https://rancher.com/docs/k3s/latest/en/installation/ha-embedded/
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Setting up a loadbalancer or VIP beforehand to use as the API endpoint is possible but not covered here.
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Start provisioning of the cluster using the following command:
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```bash
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ansible-playbook playbook/site.yml -i inventory.yml
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```
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## Upgrading
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A playbook is provided to upgrade K3s on all nodes in the cluster. To use it, update `k3s_version` with the desired version in `inventory.yml` and run:
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```bash
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ansible-playbook playbook/upgrade.yml -i inventory.yml
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```
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## Kubeconfig
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After successful bringup, the kubeconfig of the cluster is copied to the control node and set as default (`~/.kube/config`).
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Assuming you have [kubectl](https://kubernetes.io/docs/tasks/tools/#kubectl) installed, you to confirm access to your **Kubernetes** cluster use the following:
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```bash
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kubectl get nodes
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```
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## Local Testing
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A Vagrantfile is provided that provision a 5 nodes cluster using Vagrant (LibVirt or Virtualbox as provider). To use it:
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```bash
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vagrant up
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```
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By default, each node is given 2 cores and 2GB of RAM and runs Ubuntu 20.04. You can customize these settings by editing the `Vagrantfile`.
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## Need More Features?
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This project is intended to provide a "vanilla" K3s install. If you need more features, such as:
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- Private Registry
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- Advanced Storage (Longhorn, Ceph, etc)
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- External Database
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- External Load Balancer or VIP
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- Alternative CNIs
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See these other projects:
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- https://github.com/PyratLabs/ansible-role-k3s
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- https://github.com/techno-tim/k3s-ansible
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- https://github.com/jon-stumpf/k3s-ansible
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- https://github.com/alexellis/k3sup
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