A Shell Script to Backup MongoDB Databases

Did you know that MongoDB databases have a built-in way to make backups using the shell or the mongod process? The mongod process automatically takes a snapshot (a quick copy) when the database starts, stops, upgrades, or recovers from a crash. But these snapshots are not enough in case something bad happens, like disk damage or a natural disaster. To keep your data safe, it is a good idea to set up an automatic backup system for your MongoDB databases.

In this article, we will explain how to create automatic backups for your MongoDB databases using a simple Shell script.

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Shell Script for MongoDB Backup

The shell script for backing up MongoDB databases is available on GitHub. You can use the link below to access the script.

https://github.com/tecrahul/shell-scripts/blob/master/backup-mongo.sh

You can also copy the script below and save it on your Linux system.

#!/bin/bash
 
######################################################################
##   MongoDB Database Backup Script 
##   Written By: Rahul Kumar
##   URL: https://tecadmin.net/shell-script-backup-mongodb-database/
##   Updated on: June 20, 2020
######################################################################
 
export PATH=/bin:/usr/bin:/usr/local/bin
TODAY=`date +"%d%b%Y"`
 
######################################################################
 
DB_BACKUP_PATH='/backup/mongo'
MONGO_HOST='localhost'
MONGO_PORT='27017'

# If MongoDB needs a username and password to access
# Set AUTH_ENABLED to 1 
# and correctly add MONGO_USER and MONGO_PASSWD values

AUTH_ENABLED=0
MONGO_USER=''
MONGO_PASSWD=''

# To backup all databases, set DATABASE_NAMES to "ALL"
# Or, to backup only some databases, list their names separated by spaces

DATABASE_NAMES='ALL'
#DATABASE_NAMES='mydb db2 newdb'

## Number of days to keep a backup copy
BACKUP_RETAIN_DAYS=30   
 
######################################################################

mkdir -p ${DB_BACKUP_PATH}/${TODAY}

AUTH_PARAM=""

if [ ${AUTH_ENABLED} -eq 1 ]; then
	AUTH_PARAM=" --username ${MONGO_USER} --password ${MONGO_PASSWD} "
fi

if [ ${DATABASE_NAMES} = "ALL" ]; then
	echo "You have chosen to backup all databases"
	mongodump --host ${MONGO_HOST} --port ${MONGO_PORT} ${AUTH_PARAM} --out ${DB_BACKUP_PATH}/${TODAY}/
else
	echo "Backing up selected databases"
	for DB_NAME in ${DATABASE_NAMES}
	do
		mongodump --host ${MONGO_HOST} --port ${MONGO_PORT} --db ${DB_NAME} ${AUTH_PARAM} --out ${DB_BACKUP_PATH}/${TODAY}/
	done
fi

######## Remove backups older than {BACKUP_RETAIN_DAYS} days ########
 
DBDELDATE=`date +"%d%b%Y" --date="${BACKUP_RETAIN_DAYS} days ago"`
 
if [ ! -z ${DB_BACKUP_PATH} ]; then
      cd ${DB_BACKUP_PATH}
      if [ ! -z ${DBDELDATE} ] && [ -d ${DBDELDATE} ]; then
            rm -rf ${DBDELDATE}
      fi
fi
 
######################### End of script ##############################

Run Script Manually

Save the script above in a file with a .sh extension. If you want to save backups in a specific directory, place the script there. Then, give the script permission to run.

chmod +x /backup/backup-mongo.sh

Run the shell script with this command:

bash /backup/backup-mongo.sh

Schedule MongoDB Backup Script

You can set up this script to run automatically at a regular time using crontab. To edit crontab, use the crontab -e command and add the following line:

## Backup database daily at 02:00 AM
0 2 * * * /backup/mongo-backup.sh

Wrap Up

In this tutorial, we talked about a shell script that helps you manually backup MongoDB databases. You can also schedule the script to run backups automatically on a regular basis.