bootkube-terraform

bootkube-terraform is Terraform module that renders kubernetes-incubator/bootkube bootstrapping assets. It functions as a low-level component of the Typhoon Kubernetes distribution.

The module provides many of the same variable names, defaults, features, and outputs as running bootkube render directly.

Usage

Use Typhoon to create and manage Kubernetes clusters in different environments. Use bootkube-terraform if you require low-level customizations to the control plane or wish to build your own distribution.

Add the bootkube-terraform module alongside existing Terraform configs. Provide the variables listed in variables.tf or check terraform.tfvars.example for examples.

module "bootkube" {
  source = "git://https://github.com/dghubble/bootkube-terraform.git?ref=SHA"

  cluster_name = "example"
  api_servers = ["node1.example.com"]
  etcd_servers = ["node1.example.com"]
  asset_dir = "/home/core/clusters/mycluster"
  experimental_self_hosted_etcd = false
}

Alternately, use a local checkout of this repo and copy terraform.tfvars.example to terraform.tfvars to generate assets without an existing terraform config repo.

Generate the bootkube assets.

terraform get
terraform plan
terraform apply

Comparison

Render bootkube assets directly with bootkube v0.6.2.

On-host etcd

bootkube render --asset-dir=assets --api-servers=https://node1.example.com:443 --api-server-alt-names=DNS=node1.example.com --etcd-servers=https://node1.example.com:2379

Compare assets. The only diffs you should see are TLS credentials.

pushd /home/core/mycluster
mv manifests-networking/* manifests
popd
diff -rw assets /home/core/mycluster

Self-hosted etcd

bootkube render --asset-dir=assets --api-servers=https://node1.example.com:443 --api-server-alt-names=DNS=node1.example.com --experimental-self-hosted-etcd

Compare assets. Note that experimental must be generated to a separate directory for terraform applies to sync. Move the experimental bootstrap-manifests and manifests files during deployment.

pushd /home/core/mycluster
mv experimental/bootstrap-manifests/* boostrap-manifests
mv experimental/manifests/* manifests
mv manifests-networking/* manifests
popd
diff -rw assets /home/core/mycluster