bin/manage_nodes

#!/bin/bash

# "System extensions are only activated during the installation or upgrade of Talos Linux.
# With system extensions installed, the Talos root filesystem is still immutable and read-only."
# https://www.talos.dev/v1.5/talos-guides/configuration/system-extensions/
upgrade_node(){
  for node in $(echo $1 | sed "s/,/ /g"); do

    until kubectl get node $node --kubeconfig $tmp_dir/kubeconfig > /dev/null 2>&1 ; do
      echo "Waiting for node..."
      sleep 5
    done

    talosctl upgrade \
      --nodes $node \
      --preserve=true \
      --wait

    sleep 30
  done
}

# Ensure that a node is also removed from the cluster when Terraform destroys it.
# https://www.talos.dev/v1.5/talos-guides/howto/scaling-down/
remove_node(){
  talosctl reset --nodes $1
  talosctl shutdown --nodes $1
  kubectl delete node $1
}

main(){
  tmp_dir=$(mktemp -d)
  command=$1
  nodes=$2

  terraform output -raw kubeconfig > $tmp_dir/kubeconfig
  terraform output -raw talosconfig > $tmp_dir/talosconfig

  export KUBECONFIG=$tmp_dir/kubeconfig
  export TALOSCONFIG=$tmp_dir/talosconfig

  if [ "$command" = "upgrade" ]; then
    upgrade_node "$nodes"
  elif [ "$command" = "remove" ]; then
    remove_node "$nodes"
  else
    echo "No command given"
    exit 1
  fi

  rm -rf $tmp_dir
}

main "$@"