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Deploying and Managing with Rancher

Kube-Hetzner provides seamless integration with Rancher Manager, allowing you to deploy and manage your Kubernetes clusters through Rancher's web-based interface.

Overview​

Rancher is a complete software stack for teams adopting containers. It addresses the operational and security challenges of managing multiple Kubernetes clusters across any infrastructure.

Prerequisites​

  • Powerful Control Plane Nodes: Rancher requires at least 4GB of RAM per control plane node
  • DNS Configuration: You need a domain name pointing to your cluster's load balancer
  • SSL Certificate: Rancher requires HTTPS, so ensure you have TLS configured

Configuration​

Enabling Rancher​

Set the enable_rancher variable to deploy Rancher Manager:

enable_rancher = true
rancher_hostname = "rancher.example.com"
rancher_bootstrap_password = "your-secure-password"

Required Variables​

  • rancher_hostname: The fully qualified domain name for Rancher (must have DNS pointing to your load balancer)
  • rancher_bootstrap_password: Initial password for the Rancher admin user

Optional Variables​

  • rancher_install_channel: Rancher installation channel (default: latest)
  • rancher_values: Custom Helm values for Rancher deployment

Complete Example​

module "kube-hetzner" {
  # ... other configuration ...

  enable_rancher = true
  rancher_hostname = "rancher.mycompany.com"
  rancher_bootstrap_password = "ChangeMe123!"
  rancher_install_channel = "stable"

  control_plane_nodepools = [
    {
      name        = "control-plane"
      server_type = "cx31"  # At least 4GB RAM required
      location    = "nbg1"
      count       = 3
    }
  ]

  # Ensure TLS is configured
  ingress_controller = "traefik"
  traefik_values = <<EOT
ingressClass:
  enabled: true
  isDefaultClass: true
EOT
}

Installation Process​

  1. Deploy Cluster: Terraform will deploy your Kubernetes cluster with Rancher
  2. DNS Setup: Point your rancher_hostname to the cluster's load balancer IP
  3. SSL Certificate: Rancher will automatically provision a Let's Encrypt certificate if configured
  4. Access Rancher: Navigate to https://rancher_hostname and log in with admin and your bootstrap password

Rancher Configuration​

Custom Helm Values​

You can customize Rancher deployment using the rancher_values variable:

rancher_values = <<EOT
replicas: 3
ingress:
  tls:
    source: "letsEncrypt"
    letsEncrypt:
      email: "admin@example.com"
EOT

Installation Channels​

  • latest: Latest stable release
  • stable: Previous stable release
  • alpha: Alpha releases (not recommended for production)

Post-Installation​

First Login​

  1. Open https://rancher_hostname in your browser
  2. Accept the self-signed certificate warning (if using self-signed)
  3. Log in with username admin and your rancher_bootstrap_password
  4. Change the default password when prompted

Adding Clusters​

Rancher can manage:

  • The local cluster (automatically imported)
  • Additional Kubernetes clusters
  • Imported clusters from other providers

Troubleshooting​

Common Issues​

  1. Insufficient RAM: Ensure control plane nodes have at least 4GB RAM
  2. DNS Resolution: Verify rancher_hostname resolves to the load balancer
  3. SSL Issues: Check TLS configuration and certificate validity
  4. Bootstrap Password: Ensure the password meets Rancher's requirements

Logs​

Check Rancher logs:

kubectl logs -n cattle-system deployment/rancher

Resetting Rancher​

If you need to reset Rancher:

kubectl delete namespace cattle-system
# Then re-run Terraform apply

Best Practices​

  1. Use External Database: For production, configure an external database for Rancher
  2. Backup Regularly: Implement regular backups of Rancher and cluster data
  3. Monitor Resources: Keep an eye on control plane resource usage
  4. Security: Use strong passwords and enable multi-factor authentication
  5. Updates: Keep Rancher updated to the latest stable version