docker/frontend-mem-nag.sh

#!/usr/bin/env bash
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

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