backup.mongo.plugin

#!/bin/bash
# =================================================================================================================
# Mongo Backup and Restore Functions:
# - Dynamically loaded as a plug-in
# -----------------------------------------------------------------------------------------------------------------
export serverDataDirectory="/var/lib/mongodb/data"

function onBackupDatabase(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}
    _backupFile=${2}

    _hostname=$(getHostname ${_databaseSpec})
    _database=$(getDatabaseName ${_databaseSpec})
    _port=$(getPort ${_databaseSpec})
    _portArg=${_port:+"--port=${_port}"}
    _username=$(getUsername ${_databaseSpec})
    _password=$(getPassword ${_databaseSpec})
    echoGreen "Backing up '${_hostname}${_port:+:${_port}}${_database:+/${_database}}' to '${_backupFile}' ..."

    _authDbArg=${MONGODB_AUTHENTICATION_DATABASE:+"--authenticationDatabase ${MONGODB_AUTHENTICATION_DATABASE}"}
    mongodump -h "${_hostname}" -d "${_database}" ${_authDbArg} ${_portArg} -u "${_username}" -p "${_password}" --quiet --gzip --archive=${_backupFile}
    return ${?}
  )
}

function onRestoreDatabase(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}
    _fileName=${2}
    _adminPassword=${3}

    _hostname=$(getHostname ${flags} ${_databaseSpec})
    _database=$(getDatabaseName ${_databaseSpec})
    _port=$(getPort ${flags} ${_databaseSpec})
    _portArg=${_port:+"--port=${_port}"}
    _username=$(getUsername ${_databaseSpec})
    _password=$(getPassword ${_databaseSpec})
    echo -e "Restoring '${_fileName}' to '${_hostname}${_port:+:${_port}}${_database:+/${_database}}' ...\n" >&2

    # ToDo:
    # - Add support for restoring to a different database.
    #   The following implementation only supports restoring to a database of the same name, 
    #   unlike the postgres implementation that allows the database to be restored to a database of a different
    #   name for testing.
    #   Ref: https://stackoverflow.com/questions/36321899/mongorestore-to-a-different-database

    _authDbArg=${MONGODB_AUTHENTICATION_DATABASE:+"--authenticationDatabase ${MONGODB_AUTHENTICATION_DATABASE}"}
    mongorestore --drop -h ${_hostname} -d "${_database}" ${_authDbArg} ${_portArg} -u "${_username}" -p "${_password}" --gzip --archive=${_fileName} --nsInclude="*"
    return ${?}
  )
}

function onStartServer(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}

    # Start a local MongoDb instance
    MONGODB_DATABASE=$(getDatabaseName "${_databaseSpec}") \
    MONGODB_USER=$(getUsername "${_databaseSpec}") \
    MONGODB_PASSWORD=$(getPassword "${_databaseSpec}") \
    MONGODB_ADMIN_PASSWORD=$(getPassword "${_databaseSpec}") \
    run-mongod >/dev/null 2>&1 &
  )
}

function onStopServer(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}

    _port=$(getPort ${_databaseSpec})
    _portArg=${_port:+"--port ${_port}"}
    _username=admin
    _password=$(getPassword ${_databaseSpec})

    _authDbArg=${MONGODB_AUTHENTICATION_DATABASE:+"--authenticationDatabase ${MONGODB_AUTHENTICATION_DATABASE}"}
    mongo admin ${_authDbArg} ${_portArg} -u "${_username}" -p "${_password}" --quiet --eval "db.shutdownServer()"

    # Wait for server to stop ...
    local startTime=${SECONDS}
    printf "waiting for server to stop"
    while onPingDbServer ${@}; do
      printf "."
      local duration=$(($SECONDS - $startTime))
      if (( ${duration} >= ${DATABASE_SERVER_TIMEOUT} )); then
        echoRed "\nThe server failed to stop within $(getElapsedTimeFromDuration ${duration})."
        echoRed "Killing the mongod process ...\n"
        pkill -INT mongod
        break
      fi
      sleep 1
    done
  )
}

function onCleanup(){
  (
    if ! dirIsEmpty ${serverDataDirectory}; then
      # Delete the database files and configuration
      echo -e "Cleaning up ...\n" >&2
      rm -rf ${serverDataDirectory}/*
    else
      echo -e "Already clean ...\n" >&2
    fi
  )
}

function onPingDbServer(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}

    _hostname=$(getHostname ${flags} ${_databaseSpec})
    _database=$(getDatabaseName ${_databaseSpec})
    _port=$(getPort ${flags} ${_databaseSpec})
    _portArg=${_port:+"--port ${_port}"}
    _username=$(getUsername ${_databaseSpec})
    _password=$(getPassword ${_databaseSpec})

    _dbAddressArg=${_hostname}${_port:+:${_port}}${_database:+/${_database}}
    _authDbArg=${MONGODB_AUTHENTICATION_DATABASE:+"--authenticationDatabase ${MONGODB_AUTHENTICATION_DATABASE}"}
    if mongo ${_dbAddressArg} ${_authDbArg} -u "${_username}" -p "${_password}" --quiet --eval='quit()' >/dev/null 2>&1; then
      return 0
    else
      return 1
    fi
  )
}

function onVerifyBackup(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}

    _hostname=$(getHostname -l ${_databaseSpec})
    _database=$(getDatabaseName ${_databaseSpec})
    _port=$(getPort -l ${_databaseSpec})
    _portArg=${_port:+"--port ${_port}"}
    _username=$(getUsername ${_databaseSpec})
    _password=$(getPassword ${_databaseSpec})

    _dbAddressArg=${_hostname}${_port:+:${_port}}${_database:+/${_database}}
    _authDbArg=${MONGODB_AUTHENTICATION_DATABASE:+"--authenticationDatabase ${MONGODB_AUTHENTICATION_DATABASE}"}
    collections=$(mongo ${_dbAddressArg} ${_authDbArg} -u "${_username}" -p "${_password}" --quiet --eval 'var dbs = [];dbs = db.getCollectionNames();for (i in dbs){ print(db.dbs[i]);}';)
    rtnCd=${?}

    # Get the size of the restored database
    if (( ${rtnCd} == 0 )); then
      size=$(getDbSize -l "${_databaseSpec}")
      rtnCd=${?}
    fi

    if (( ${rtnCd} == 0 )); then
      numResults=$(echo "${collections}"| wc -l)
      if [[ ! -z "${collections}" ]] && (( numResults >= 1 )); then
        # All good
        verificationLog="\nThe restored database contained ${numResults} collections, and is ${size} in size."
      else
        # Not so good
        verificationLog="\nNo collections were found in the restored database ${_database}."
        rtnCd="3"
      fi
    fi

    echo ${verificationLog}
    return ${rtnCd}
  )
}

function onGetDbSize(){
  (
    local OPTIND
    local unset flags
    while getopts : FLAG; do
      case $FLAG in
        ? ) flags+="-${OPTARG} ";;
      esac
    done
    shift $((OPTIND-1))

    _databaseSpec=${1}

    _hostname=$(getHostname ${flags} ${_databaseSpec})
    _database=$(getDatabaseName ${_databaseSpec})
    _port=$(getPort ${flags} ${_databaseSpec})
    _portArg=${_port:+"--port ${_port}"}
    _username=$(getUsername ${_databaseSpec})
    _password=$(getPassword ${_databaseSpec})

    _dbAddressArg=${_hostname}${_port:+:${_port}}${_database:+/${_database}}
    _authDbArg=${MONGODB_AUTHENTICATION_DATABASE:+"--authenticationDatabase ${MONGODB_AUTHENTICATION_DATABASE}"}
    size=$(mongo ${_dbAddressArg} ${_authDbArg} -u "${_username}" -p "${_password}" --quiet --eval 'printjson(db.stats().fsTotalSize)')
    rtnCd=${?}

    echo ${size}
    return ${rtnCd}
  )
}
# =================================================================================================================