#!/bin/sh
#
# check available RAM and IPv4s

ram_bytes_to_allocate="$1"
ram_bytes_available=$(grep -E "^(size|memory_available_bytes)" /proc/spl/kstat/zfs/arcstats | awk '{sum+=$3} END {printf "%.0f", sum}')
ram_bytes_remainder="$((ram_bytes_available - ram_bytes_to_allocate))"

if echo "$ram_bytes_to_allocate" | grep -vqE "^[0-9]+$"; then
  echo "ram_bytes_to_allocate \"$ram_bytes_to_allocate\" must be an integer"
  exit 1
fi

# 20GB
if [ "$ram_bytes_remainder" -le $((20 * 1024 * 1024 * 1024)) ]; then
  echo "VM is requesting more RAM than $(hostname -f) has available."
  echo "Bytes requested: $ram_bytes_to_allocate"
  echo "Bytes available: $ram_bytes_available"
  exit 1
fi

ipv4_limit=61
total_addresses_used=$(virsh net-dhcp-leases public3 | grep -E '.+' | tail -n +3 | wc -l)

if [ "$total_addresses_used" -ge "$ipv4_limit" ]; then
  echo "IPv4 address limit reached"
  exit 1
fi

echo "yes"