Scripts to configure a mongodb environment

mongod.conf.mmapv1

storage:
  dbPath: /var/lib/mongodb
  repairPath: /var/lib/mongodb/.repair
  directoryPerDB: true
  journal:
    enabled: true
  engine: "mmapv1"
  mmapv1:
    smallFiles: true

systemLog:
  destination: file
  path: /var/log/mongodb/mongod.log
  logAppend: true
  timeStampFormat: iso8601-utc

processManagement:
  fork: true
  pidFilePath: /run/mongod/mongod.pid

net:
  bindIp: 127.0.0.1
  port: 27017
  unixDomainSocket:
    enabled : true

security:
  authorization: disabled

setParameter:
  enableLocalhostAuthBypass: false

mongod.conf.wiredtiger

storage:
  dbPath: /var/lib/mongodb
  directoryPerDB: true
  journal:
    enabled: true
  engine: "wiredTiger"
  wiredTiger:
    engineConfig:
      #cacheSizeGB: 0
      journalCompressor: zlib
    collectionConfig:
      blockCompressor: zlib
    indexConfig:
      prefixCompression: true

systemLog:
  destination: file
  path: /var/log/mongodb/mongod.log
  logAppend: true
  timeStampFormat: iso8601-utc

processManagement:
  fork: true
  pidFilePath: /run/mongod/mongod.pid

net:
  bindIp: 127.0.0.1
  port: 27017
  unixDomainSocket:
    enabled : true

security:
  authorization: disabled

setParameter:
  enableLocalhostAuthBypass: false

mongodb-credentials.json

{
    "username": ":username:",
    "password": ":password:",
    "host": ":host:",
    "port": ":port:",
    "uri": ":uri:"
}

setup_mongo_resource_limits.sh

#!/bin/bash

function setup_mongo_resource_limits() {
    local bytes=1073741824
    
    # we're using 70% of the system available memory
    local mongo_usage=$(echo "(70 / 100.0)" | bc -l)

    local total_mem=$(cat /proc/meminfo| grep -i memtotal | awk '{print $2}')
    local container_memory=$(echo "(${total_mem} / (1024 * 1024)) * ${mongo_usage}" | bc -l)
    local cache_memory=$(printf "%.0f" ${container_memory})

    # 50% of the container memory - 1GB
    cache_memory=$(echo "((${cache_memory} * 0.5) - 1) / 1" | bc)
    
    # normalize the mongo service and configuration file
    sed -i '/\(MemoryAccounting\|MemoryLimit\)/d' /lib/systemd/system/mongod.service
    sed -i "s:\\(#\)\(cacheSizeGB\:\):\2:" /etc/mongod.conf
    
    # set the cacheSizeGB
    sed -i "s:\(cacheSizeGB\:\).*$:\1 ${cache_memory}:" /etc/mongod.conf

    if [[ $(echo "${cache_memory} > 0" | bc) -eq 0 ]]
    then
        # comment the cacheSizeGB
        sed -i "s:\(cacheSizeGB\:.*$\):#\1:" /etc/mongod.conf
    fi

    container_memory=$(echo "${container_memory} * ${bytes}" | bc)
    container_memory=${container_memory%.*}
    
    # set container memory
    sed -i "/LimitNPROC=64000/ a\\
MemoryAccounting=yes\n\
MemoryLimit=${container_memory}" /lib/systemd/system/mongod.service
}

setup_mongo_resource_limits
systemctl daemon-reload
systemctl restart mongod.service

setup_mongodb_credentials.sh

#!/bin/bash

if [ \( -n "$1" \) -a \( "$1" = "-h" -o "$1" = "--help" \) ]; then
    echo "Argument List:"
    echo "username (\$1) - The username to connect to the database (default: \"\")"
    echo "password (\$2) - The password used for the user (default: \"\")"
    echo "host (\$3) - The host where the database is running (default: 127.0.0.1)"
    echo "port (\$4) - The port that the database is listening (default: 27017)"
    echo ""
    exit 0
fi

function enable_mongodb_auth() {
  sed -i "s:\(authorization\:\).*$:\1 enabled:" /etc/mongod.conf
}

function disable_mongodb_auth() {
  sed -i "s:\(authorization\:\).*$:\1 disabled:" /etc/mongod.conf
}

function setup_mongo_credentials() {
    local credentials_file=/tmp/credentials.json

    sed -i "s|\(\"username\"\:\)\( \".*\"\)|\1 \"${USERNAME}\"|g" ${credentials_file}
    sed -i "s|\(\"password\"\:\)\( \".*\"\)|\1 \"${PASSWORD}\"|g" ${credentials_file}
    sed -i "s|\(\"host\"\:\)\( \".*\"\)|\1 \"${HOST}\"|g" ${credentials_file}
    sed -i "s|\(\"port\"\:\)\( \".*\"\)|\1 \"${PORT}\"|g" ${credentials_file}
    sed -i "s|\(\"uri\"\:\)\( \".*\"\)|\1 \"${URI}\"|g" ${credentials_file}
}

USERNAME="${1-}"
PASSWORD="${2-}"
HOST="${3-127.0.0.1}"
PORT="${4-27017}"

URI="mongodb://"

disable_mongodb_auth

if [ ! -z "${USERNAME}" ]; then
    enable_mongodb_auth
    URI="${URI}${USERNAME}:${PASSWORD}@"
fi

URI="${URI}${HOST}:${PORT}/"

setup_mongo_credentials