Terraform Your Kubernetes Cluster on OpenStack with Kubeadm

This repo provides the bootstrap scripts to create a Kubernetes development cluster on an OpenStack cloud with the kubeadm tool.

It has been written to minimize dependencies -- you will only needs to install terraform, this repo and kubectl on your laptop to get a fully functional cluster running.

What Does This Do ?

At the conclusion of the scripts, you will have one Kubernetes master node and x Kubernetes worker nodes. In your OpenStack Horizon dashboard you will see this (where x == 2 worker nodes):

As you can see, Terraform has created the following in your OpenStack cloud:

• One VM instance for the Kubernetes Master node
• One floating / public IP address for the Kubernetes Master node
• Two (configurable number) VM instances for the Kubernetes Workers nodes
• Tenant/project network and subnet
• Tenant/project router that connects to provide network/internet

It has also configured the following on that OpenStack infrastructure:

• Installed Kubernetes master node on kube-master via kubeadm init
• Installs and registers a variable number of worker nodes with Kubernetes software with kubeadm join
• Configures new Kubernetes cluster with Weave networking
• Writes and retrieves kubectl configuration file
• Installs KubeDNS, Kubernetes Dashboard and WeaveScope add-ons LINKS
• Sets up easy aliases for usage of new cluster

Logically, your new Kubernetes cluster now looks like this (using the installed WeaveScope tool):

What Does This NOT Do ?

• High availability control plane
• High availability etcd cluster
• Host on any other cloud than OpenStack
• Host on any other operating system than Ubuntu 16.04 LTS
• (YET) Setup OpenStack cloud provider specific options (persistent storage, load balancer)

Cluster Creation

Choose your own adventure below, depending on your level of impulse control.

For The impatient

$ brew install kubectl terraform jq
$ curl -o tf.zip https://github.com/slashk/terra-kubeadm-on-os/archive/master.zip
$ unzip tf.zip
$ cd terra-kubeadm-on-os-master
$ cp sample.tfvars terraform.tfvars
$ vi terraform.tfvars
$ terraform plan
$ terraform apply
$ ./post-install.sh
$ source ./commands.alias

These lines:

• Sets your default variables (using the sample.tfvars file that you edited)
• installs terraform to create your infrastructure and kubectl to control your cluster
• downloads and unzips this repo for the terraform scripts
• runs terraform plan (preflight) then terraform apply to create the OpenStack infrastructure for the cluster (this will take a while -- five minutes on my cloud)
• executes a small bash script to setup your local laptop and twiddles some server settings to communicate with the new cluster
• sources some convienence commands to make it easy to REWORK

For The More Thoughtful

See this blog post

FAQ

What if I want my Kubernetes cluster on another cloud ?

Use another tool:

• Kops for AWS
• Google Container Enginer (GKE) on Google Cloud
• Azure Container Service on Microsoft Azure

What if I want a Kubernetes cluster on my laptop ?

Minikube is your boy. I use it with the xhyve driver on my Mac.