Rancher on k3s Automated Script

This script automates the setup of a k3s cluster with the Rancher UI, including Let's Encrypt SSL for secure access. This can help you quickly create new clusters for testing, development, or learning purposes.

Disclaimer

Although you can use this cluster for deploying real applications, please be aware that I am currently unaware of all potential caveats.

Features

• Automated k3s Cluster Setup: Easily set up a lightweight Kubernetes cluster using k3s.
• Rancher UI: Deploy Rancher for simplified Kubernetes cluster management.
• High availability: Support highly available local Rancher cluster with embedded etcd.
• Let's Encrypt SSL: Automatically configure SSL certificates for secure access to the Rancher UI.
• Public IP Detection: Automatically detect and use your VM's public IP for configuration of the DNS A record.
• Environment Variables Exposure: Set environment variables to bypass interactive prompts and automate the setup process.
  • K3S_TOKEN and K3S_URL: Use these to join an existing cluster.
  • LETSENCRYPT_EMAIL and RANCHER_HOSTNAME: Use these for Rancher installation.
  • Additional environment variables can be set to override defaults or user-provided inputs.
• User Prompts: Interactive script prompts to customize the setup according to your needs.

Prerequisites

• Ubuntu or Debian-based system: The script is designed to work on these operating systems.
• sudo privileges: The script requires elevated privileges to install dependencies and configure the system.

Installation

You can install the script using either curl or wget.

Install with cURL

To install and run the script using curl, execute the following command in your terminal:

sudo -E bash -c "$(curl -fsSL https://raw.githubusercontent.com/teyfix/rancher/265619e1985165ecd5baf86b051ad3ceae04f4d1/install.sh)"

Install with wget

To install and run the script using wget, execute the following command in your terminal:

sudo -E bash -c "$(wget -qO- https://raw.githubusercontent.com/teyfix/rancher/265619e1985165ecd5baf86b051ad3ceae04f4d1/install.sh)"

Environment Variables

The script supports the following environment variables to customize the installation:

• K3S_URL: URL of the existing k3s cluster to join.
  • K3S_URL will be provided to you after the first installation.
  • You can also use the master node's public/private IP.
  • You must ensure new nodes can access to the K3S API endpoint. (Default is https://<master_hostname>:6443)
• K3S_TOKEN: Token to join an existing k3s cluster.
  • K3S_TOKEN will be generated and printed to you after the first installation if you don't provide one.
• LETSENCRYPT_EMAIL: Email for Let's Encrypt SSL certificate registration.
• RANCHER_HOSTNAME: FQDN to access the Rancher UI.
• RANCHER_NAMESPACE: Namespace for Rancher installation (default is cattle-system).
• RANCHER_REPO: Rancher Helm repository (default is rancher-stable).
• RANCHER_PASSWORD: Password for Rancher UI access.

Also any other k3s environment variables are supported by k3s itself. Checkout installation and advanced configuration documentations respectively.

Example Usage

To automate the setup using environment variables, export them before running the script:

export K3S_TOKEN=<your_k3s_token>
export K3S_URL=https://<master_hostname>:6443
export LETSENCRYPT_EMAIL=<your_email>
export RANCHER_HOSTNAME=<your_rancher_hostname>

Post-Installation

• After running the script, your k3s cluster with Rancher UI will be set up. You can access the Rancher UI using the provided FQDN and manage your Kubernetes clusters easily.
• You don't have to SSH to the machine after the Rancher UI is up. You can use the kubectl CLI provided by Rancher to easily run commands.

Future Improvements

• I am considering adding Terraform scripts for various cloud providers.

Feedback and Contributions

I welcome any feedback and contributions to improve this script. Feel free to open an issue or submit a pull request on this GitHub repository.

License

This project is licensed under the MIT License - see the LICENSE file for details.