Essential Shell Scripts Every Ops Engineer Should Use

When working on frontline operations, having a set of ready-to-use shell scripts can greatly improve efficiency and reliability. Below are ten common Bash scripts that address typical tasks in system administration.

System load monitoring : Checks the system load using uptime and sends an email alert if the load exceeds a defined threshold.

#!/bin/bash
threshold=1.0
load=$(uptime | awk -F'[, ]+' '{print $(NF-2)}')
if (( $(echo "$load > $threshold" | bc -l) )); then
    echo "System load too high: $load" | mail -s "Load Alert" [email protected]
fi

File backup : Periodically backs up a specified directory using cp and a cron job.

#!/bin/bash
backup_dir="/path/to/backup"
source_dir="/path/to/source"
timestamp=$(date +%Y%m%d%H%M%S)
backup_file="backup_${timestamp}.tar.gz"
tar czf "${backup_dir}/${backup_file}" "${source_dir}"

Log file cleanup : Removes log files older than a configurable number of days using find .

#!/bin/bash
log_dir="/path/to/logs"
days_to_keep=7
find "$log_dir" -type f -name "*.log" -mtime +$days_to_keep -delete

Service status monitoring : Checks whether a critical service (e.g., nginx ) is active with systemctl and emails an alert if it is not.

#!/bin/bash
service_name="nginx"
if ! systemctl is-active --quiet "$service_name"; then
    echo "Service $service_name is not running" | mail -s "Service Alert" [email protected]
fi

Automated deployment : Uses rsync in a loop to copy files to multiple servers.

#!/bin/bash
servers=("server1" "server2" "server3")
source_dir="/path/to/source"
destination_dir="/path/to/destination"
for server in "${servers[@]}"; do
    rsync -avz "$source_dir" "$server:$destination_dir"
done

Disk space monitoring : Parses df -h output and sends an email when usage exceeds a set percentage.

#!/bin/bash
threshold=90
df_output=$(df -h)
while read -r line; do
    usage=$(echo "$line" | awk '{print $5}' | sed 's/%//')
    if (( usage > threshold )); then
        echo "Disk space low: $line" | mail -s "Disk Alert" [email protected]
    fi
done <<< "$df_output"

Temporary file cleanup : Deletes files in a temporary directory older than a defined number of days.

#!/bin/bash
temp_dir="/path/to/temp"
expiration_days=3
find "$temp_dir" -type f -mtime +$expiration_days -delete

Network connectivity monitoring : Pings a critical IP address and alerts if the host is unreachable.

#!/bin/bash
service_ip="192.168.0.1"
if ! ping -c 1 -W 1 "$service_ip" > /dev/null; then
    echo "Cannot reach service: $service_ip" | mail -s "Network Alert" [email protected]
fi

Batch file renaming : Renames files in a directory with a sequential prefix.

#!/bin/bash
directory="/path/to/files"
prefix="new_file"
count=1
for file in "$directory"/*; do
    new_file_name="$directory/${prefix}${count}"
    mv "$file" "$new_file_name"
    ((count++))
 done

Start/stop multiple services : Loops over a list of services and runs systemctl start or systemctl stop on each.

#!/bin/bash
services=("service1" "service2" "service3")
action="start"  # or "stop"
for service in "${services[@]}"; do
    systemctl "$action" "$service"
done

These examples illustrate common operational needs; they can be adapted and extended to fit specific environments.