In the fast-paced world of DevOps, automation is king. From provisioning servers to deploying applications, Bash scripting helps engineers streamline operations and reduce manual overhead. It’s one of the most essential tools in a DevOps engineer’s toolkit.
This post’ll walk through the Top 10 Bash Scripts Every DevOps Engineer Uses, complete with code snippets, expected output, and a section on Bash vs. Dash—so even beginners can follow along.
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🧠 What is Bash (and How is it Different from Dash)?
Bash (Bourne Again Shell) is the default command-line shell for most Linux distributions. It's powerful, flexible, and supports advanced scripting features like arrays, arithmetic, and custom functions.
Dash (Debian Almquist Shell) is a lightweight, POSIX-compliant shell often used as /bin/sh for faster script execution, especially during system boot.
⚙️ Key Differences:
| Feature | Bash | Dash |
|---|---|---|
| Speed | Slower | Faster |
| Features | Rich (arrays, functions) | Minimal (POSIX only) |
| Interactive Use | Common | Rare |
| Used for | General scripting | System scripts (init, boot) |
| Compatibility | Bash-specific scripts may break in Dash | Fully POSIX compliant |
🔎 Important Tip: Always start your Bash scripts with #!/bin/bash, not #!/bin/sh, if you’re using Bash-specific syntax.
✅ Top 10 Bash Scripts Every DevOps Engineer Uses
1. ✅ Server Health Check Script
#!/bin/bash
echo "Checking system health..."
uptime
df -h
free -m
top -b -n1 | head -15
📤 Expected Output:
Checking system health...
11:03:45 up 3 days, 2:11, 2 users, load average: 0.23, 0.15, 0.12
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 50G 25G 23G 52% /
total used free
Mem: 7989 4121 3868
...
🎯 Use case: Quickly diagnose system health before deploying.
2. ✅ Automated Backup Script
#!/bin/bash
BACKUP_DIR="/backup"
SRC_DIR="/var/www/html"
DATE=$(date +%F)
tar -czvf $BACKUP_DIR/site-backup-$DATE.tar.gz $SRC_DIR
📤 Expected Output:
/var/www/html/
/var/www/html/index.html
/var/www/html/assets/
📦 Use case: Automates daily website or app backups.
3. ✅ Log Rotation & Cleanup Script
#!/bin/bash
find /var/log -type f -name "*.log" -mtime +7 -exec rm -f {} \;
📤 Expected Output:
(If logs older than 7 days exist, they are silently deleted.)
🧹 Use case: Prevent disk space bloat from unused logs.
4. ✅ User Management Script
#!/bin/bash
USERNAME=$1
useradd $USERNAME
echo "$USERNAME:ChangeMe123" | chpasswd
passwd --expire $USERNAME
📤 Expected Output:
Changing password expiry information for user newdev.
passwd: password expiry information changed.
👥 Use case: Adds new users with a default password policy.
5. ✅ Service Monitor & Auto-Restart Script
#!/bin/bash
SERVICE="nginx"
if ! pgrep -x "$SERVICE" > /dev/null; then
echo "$SERVICE is down. Restarting..."
systemctl start $SERVICE
else
echo "$SERVICE is running."
fi
📤 Expected Output:
nginx is running.
# or
nginx is down. Restarting...
🔄 Use case: Minimizes downtime for critical services.
6. ✅ Deployment Script
#!/bin/bash
cd /var/www/myapp
git pull origin main
chmod -R 755 .
systemctl restart myapp
📤 Expected Output:
Updating 1a2b3c4..5d6e7f8
Fast-forward
index.html | 2 +-
🚀 Use case: Deploys the latest code with proper permissions and service restart.
7. ✅ Disk Space Alert Script
#!/bin/bash
THRESHOLD=90
USAGE=$(df / | grep / | awk '{ print $5 }' | sed 's/%//g')
if [ "$USAGE" -gt "$THRESHOLD" ]; then
echo "Disk usage is ${USAGE}% on root!" | mail -s "Disk Alert" devops@yourdomain.com
fi
📤 Expected Output:
(Sends an email if disk usage is too high.)
📉 Use case: Avoids system crashes due to full disk.
8. ✅ Database Dump Script
#!/bin/bash
DB_NAME="mydb"
USER="root"
PASS="password"
DATE=$(date +%F)
mysqldump -u$USER -p$PASS $DB_NAME > /backup/db-$DATE.sql
📤 Expected Output:
Creates a file: /backup/db-2025-05-12.sql
🗃 Use case: Automates MySQL backups for disaster recovery.
9. ✅ System Update Script
#!/bin/bash
apt update && apt upgrade -y
📤 Expected Output:
Get:1 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB]
...
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
🛡 Use case: Keeps the system patched and secure with minimal effort.
10. ✅ Cron Job Health Checker
#!/bin/bash
echo "Listing all cron jobs:"
for user in $(cut -f1 -d: /etc/passwd); do
crontab -u $user -l 2>/dev/null | grep -v "^#"
done
📤 Expected Output:
0 2 * * * /usr/bin/backup.sh
*/15 * * * * /usr/bin/monitor.sh
📆 Use case: Ensures scheduled tasks are in place and working.
🧩 Final Thoughts
These Bash scripts are the bread and butter of DevOps automation. From monitoring to deployment to backups, a well-written script can save hours of manual work—and prevent critical failures.
💡 Pro Tip: Always test your Bash scripts on a staging environment before using them in production.
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