Scaling Tectonic bare metal clusters

This document describes how to add cluster nodes to Tectonic clusters on bare metal.

Scaling worker nodes

To scale worker nodes, adjust tectonic_worker_count in terraform.vars and run:

$ terraform apply $ terraform plan \
  -var-file=build/${CLUSTER}/terraform.tfvars \
  -target module.workers \
  platforms/metal

After running terraform apply, power on the machines to PXE boot the new nodes and access the cluster.

Scaling controller nodes

Adding controller nodes to an existing Tectonic cluster on bare metal is not officially supported. This feature is planned for a future release.

etcd scaling on bare metal

Each controller in a default bare metal Tectonic cluster runs the etcd service. Tectonic Installer will also accept the client endpoint of an existing external etcd v3 cluster to which it should connect instead.