#!/usr/bin/env bash
#
# Copyright © 2024, Kanton Bern
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * Neither the name of the <organization> nor the
#       names of its contributors may be used to endorse or promote products
#       derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

set -e

# We need at least 3GB of free mem...
MIN_MEM_FREE_GB=3
MIN_MEM_FREE_KB=$(($MIN_MEM_FREE_GB*1000000))

echo_mem_warn() {
  MEM_FREE_KB=$(awk '/MemFree/ { printf "%s \n", $2 }' /proc/meminfo)
  MEM_FREE_GB=$(awk '/MemFree/ { printf "%s \n", $2/1024/1024 }' /proc/meminfo)

  if [[ "${MEM_FREE_KB}" -lt "${MIN_MEM_FREE_KB}" ]]; then
    cat <<EOF
    ===============================================
    ========  Memory Insufficient Warning =========
    ===============================================

    It looks like you only have ${MEM_FREE_GB}GB of
    memory free. Please increase your Docker
    resources to at least ${MIN_MEM_FREE_GB}GB

    ===============================================
    ========  Memory Insufficient Warning =========
    ===============================================
EOF
  else
    echo "Memory check Ok [${MEM_FREE_GB}GB free]"
  fi
}

# Always nag if they're low on mem...
echo_mem_warn
