Terraform config to launch nodes for an RKE cluster

Summary

This Terraform setup will:

• Provision Digital Ocean droplets and install the Docker daemon on these
• Create a cluster.yml configuration file containing those droplets to enable provisioning a Kubernetes clusters with Rancher Kubernetes Engine (RKE)
• Create an ssh_config file in the terraform module directory for connecting to the droplets

Other options

All available options/variables are described in terraform.tfvars.example.

How to use

• Clone this repository
• Move the file terraform.tfvars.example to terraform.tfvars and edit (see inline explanation)
• Run terraform init
• Run terraform apply
• Once terraform provisioning has completed you can provision a Kubernetes cluster with RKE rke up --config cluster.yml. The RKE binary is required and can be installed per docs
• When terraform destroy is performed, the Kubernetes CLI configuration file kube_config_cluster.yml and RKE state file cluster.rkestate auto-generated by RKE will be deleted from the directory, if present, alongside the cluster.yml created by terraform.

Installing Rancher after provisioning cluster with RKE

Rancher generated self-signed certificates

• Run ./rancher-install.sh -H <rancher hostname> -v <version string> where is the URL for the rancher server and is a version string of the format 2.2.8 for example.

letsEncrypt certificates

• Run ./rancher-install.sh -H <rancher hostname> -v <version string> -t letsEncrypt where is the URL for the rancher server and is a version string of the format 2.2.8 for example.

Custom certificates

• Run ./certs.sh <rancher hostname> where is the URL for the rancher server for which to generate certificates.
• Run ./rancher-install.sh -H <rancher hostname> -v <version string> -t secret where is the URL for the rancher server and is a version string of the format 2.2.8 for example.

SSH Config

You can use the use the auto-generated ssh_config file to connect to the droplets by droplet name, e.g. ssh <prefix>-rke-0-all or ssh <prefix>-rke-1-etcd etc. To do so, you have two options:

1. Add an Include directive at the top of the SSH config file in your home directory (~/.ssh/config) to include the ssh_config file at the location you have checked out the this repository, e.g. Include ~/git/tf-do-rke/ssh_config.

2. Specify the ssh_config file when invoking ssh via the -F option, e.g. ssh -F ~/git/tf-do-rke/ssh_config <host>.