#!/bin/bash
set -ex

# This script is used to handle the termination of login nodes instances within an AWS cluster.
# It restricts SSH access to a default user, notifies logged-in users of the upcoming termination,
# waits for a given "grace period", then notifies of the imminent shutdown.
# It is invoked with two parameters: a termination message and a gracetime period in minutes.
# The termination message will be broadcast to all logged in users, and the grace period defines
# how long the script should wait before the final system shutdown.
#
# This script must be executed as root.

DEFAULT_USER=<%= node['cluster']['cluster_user'] %>
TERMINATION_MESSAGE=$1
GRACETIME_PERIOD=$2

echo "AllowUsers $DEFAULT_USER" >> /etc/ssh/sshd_config
systemctl reload sshd
wall "$TERMINATION_MESSAGE"