How to Set Up Automated MongoDB Backup to AWS S3 on Ubuntu (Production Ready)

Goal

• ✅ Automated MongoDB backup

• ✅ Upload to AWS S3

• ✅ Run daily at 2 AM IST

• ✅ Retain only the last 7 days locally

• ✅ Production-safe cron execution

Architecture

MongoDB
↓
mongodump (gzip archive)
↓
AWS S3 upload
↓
Local retention cleanup

1️⃣ Install AWS CLI on Ubuntu

We install AWS CLI using Snap:

sudo snap install aws-cli --classic

Verify:

aws --version

2️⃣ Create IAM User (S3 Access Only)

In the AWS Console:

1. Go to IAM → Users → Create User

2. Enable programmatic access

3. Attach a policy

For quick setup:

AmazonS3FullAccess

For production (recommended), use a restricted policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "s3:PutObject",
                "s3:ListBucket"
            ],
            "Effect": "Allow",
            "Resource": [
                "arn:aws:s3:::your-bucket-name",
                "arn:aws:s3:::your-bucket-name/*"
            ]
        }
    ]
}

Save:

• Access Key

• Secret Key

3️⃣ Configure AWS on the Server

aws configure

Enter:

Access Key
Secret Key
Region (e.g. ap-south-1)
Output format: json

4️⃣ Create the Backup Script

Create the file:

nano /home/ubuntu/mongo-backup.sh

Paste:

#!/bin/bash

# === MongoDB Daily Backup Script ===

set -e

MONGO_URI="mongodb://localhost:27017/mydatabase"
BACKUP_DIR="/home/ubuntu/bkp"
DATE=$(date +"%Y-%m-%d_%H-%M-%S")
S3_BUCKET="s3://your-bucket-name"
BACKUP_NAME="backup-$DATE.gz"
RETENTION_DAYS=7
LOG_FILE="/home/ubuntu/mongo-backup.log"

mkdir -p "$BACKUP_DIR"

echo "Starting backup: $DATE" >> "$LOG_FILE"

# Dump database
/usr/bin/mongodump --uri="$MONGO_URI" --archive="$BACKUP_DIR/$BACKUP_NAME" --gzip >> "$LOG_FILE" 2>&1

# Upload to S3
/snap/bin/aws s3 cp "$BACKUP_DIR/$BACKUP_NAME" "$S3_BUCKET/" >> "$LOG_FILE" 2>&1

# Cleanup old local backups
find "$BACKUP_DIR" -type f -mtime +$RETENTION_DAYS -delete

echo "Backup completed successfully: $BACKUP_NAME" >> "$LOG_FILE"

Make it executable:

chmod +x /home/ubuntu/mongo-backup.sh

Test manually:

/home/ubuntu/mongo-backup.sh

5️⃣ Set Up the Cron Job (2 AM IST)

If your server is in UTC, 2 AM IST = 20:30 UTC (previous day).

Edit cron:

crontab -e

Add:

30 20 * * * /home/ubuntu/mongo-backup.sh >> /home/ubuntu/mongo-backup.log 2>&1

6️⃣ Add an S3 Lifecycle Rule (Highly Recommended)

Go to S3 → Bucket → Management → Lifecycle Rule and create a rule to delete objects after 30 days. This prevents infinite storage growth.

Production Recommendations

• Use an IAM role instead of access keys (if running on EC2)

• Restrict S3 permissions to a specific bucket

• Enable S3 versioning

• Enable server-side encryption (SSE-S3 or SSE-KMS)

• Periodically test the restore process — a backup you've never restored is not a backup

Up next: add failure email alerts via Amazon SES so you know immediately when a backup breaks.