#!/usr/bin/env bash
# TODO - make equivalent to https://gitlab.com/megabyte-labs/gas-station/-/blob/master/roles/system/common/tasks/linux/swap.yml

MEMORY_IN_KB="$(grep MemTotal /proc/meminfo | sed 's/.* \(\d+\) kB/\1/')"
MEMORY_IN_GB="$((MEMORY_IN_KB / 1024 / 1024))"

if [ "$MEMORY_IN_GB" -gt 64 ]; then
  SWAP_SPACE="$((MEMORY_IN_GB / 10))"
elif [ "$MEMORY_IN_GB" -gt 32 ]; then
  SWAP_SPACE="$((MEMORY_IN_GB / 8))"
elif [ "$MEMORY_IN_GB" -gt 8 ]; then
  SWAP_SPACE="$((MEMORY_IN_GB / 4))"
else
  SWAP_SPACE="$MEMORY_IN_GB"
fi

logg info "Creating a $SWAP_SPACE GB /swapfile"
sudo fallocate -l "$SWAP_SPACE" /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
if cat /etc/fstab | grep "/swapfile"; then
  sudo sed -i '/\/swapfile/\/swapfile none swap sw 0 0/' /etc/fstab
else
  echo "/swapfile none swap sw 0 0" | sudo tee -a /etc/fstab
fi