☁️ DevOps Day 7 — Build a Simple AWS Resource Tracker using Shell Script

 

🚀 Introduction

Welcome to Day 7 of the DevOps series!

In this project, you’ll build a simple AWS Resource Tracker using a few lines of shell scripting and the AWS CLI.

This script helps you monitor your AWS account — checking how many EC2 instances, S3 buckets, Lambda functions, and IAM users/roles you currently have.

You’ll also learn how to automate it with a cron job so it runs daily and stores a simple report.

 

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🧰 Prerequisites

Before starting, make sure you have:

• AWS CLI installed and configured → aws configure

• Basic Linux knowledge (creating files, running scripts)

• IAM permissions with read-only access for EC2, S3, Lambda, and IAM

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💻 Step 1: Create the Script

Create a new file named aws_resource_tracker.sh

#!/usr/bin/env bash
set -euo pipefail
# Default region (update as needed)
REGION="${AWS_DEFAULT_REGION:-ap-southeast-2}"
DATE=$(date +%F)
echo "=== AWS Resource Tracker ==="
echo "Date: ${DATE}"
echo "Region: ${REGION}"
echo
# S3 Buckets (global)
S3_BUCKETS=$(aws s3api list-buckets --query 'length(Buckets)' --output text)
echo "S3 Buckets: ${S3_BUCKETS}"
# IAM Users and Roles (global)
IAM_USERS=$(aws iam list-users --query 'length(Users)' --output text)
IAM_ROLES=$(aws iam list-roles --query 'length(Roles)' --output text)
echo "IAM Users:  ${IAM_USERS}"
echo "IAM Roles:  ${IAM_ROLES}"
# EC2 Instances (regional)
EC2_RUNNING=$(aws ec2 describe-instances --region "$REGION" \
  --filters Name=instance-state-name,Values=running \
  --query 'length(Reservations[].Instances[])' --output text 2>/dev/null || echo 0)
EC2_STOPPED=$(aws ec2 describe-instances --region "$REGION" \
  --filters Name=instance-state-name,Values=stopped \
  --query 'length(Reservations[].Instances[])' --output text 2>/dev/null || echo 0)
echo "EC2 Running: ${EC2_RUNNING}"
echo "EC2 Stopped: ${EC2_STOPPED}"
# Lambda Functions (regional)
LAMBDA_FUNCS=$(aws lambda list-functions --region "$REGION" \
  --query 'length(Functions)' --output text 2>/dev/null || echo 0)
echo "Lambda Functions: ${LAMBDA_FUNCS}"
# Save output to a report file
mkdir -p reports
REPORT_FILE="reports/aws_report_${DATE}.txt"
{
  echo "AWS Resource Report - ${DATE}"
  echo "Region: ${REGION}"
  echo "S3 Buckets: ${S3_BUCKETS}"
  echo "IAM Users: ${IAM_USERS}"
  echo "IAM Roles: ${IAM_ROLES}"
  echo "EC2 Running: ${EC2_RUNNING}"
  echo "EC2 Stopped: ${EC2_STOPPED}"
  echo "Lambda Functions: ${LAMBDA_FUNCS}"
} > "$REPORT_FILE"
echo
echo "✅ Report saved at: ${REPORT_FILE}"

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⚙️ Step 2: Make It Executable

chmod +x aws_resource_tracker.sh

Then run it:

./aws_resource_tracker.sh

You’ll get an output like this:

=== AWS Resource Tracker ===
Date: 2025-10-14
Region: ap-southeast-2
S3 Buckets: 5
IAM Users: 2
IAM Roles: 7
EC2 Running: 3
EC2 Stopped: 1
Lambda Functions: 4
✅ Report saved at: reports/aws_report_2025-10-14.txt

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⏰ Step 3: Automate It with Cron

To run it automatically every morning at 7:00 AM:

crontab -e

Add this line (update your path):

0 7 * * * /bin/bash /home/ubuntu/aws_resource_tracker.sh >> /home/ubuntu/reports/cron.log 2>&1

Now it will:

• Run daily at 7 AM

• Save a new report in reports/

• Log results in cron.log

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🔍 Step 4: Verify and Extend

You can later expand this script to:

• Track EBS volumes, RDS instances, or CloudWatch alarms

• Email the daily report using AWS SES

• Upload results to S3 for central logging

• Integrate with Slack alerts

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🌟 Summary

By the end of this project, you learned how to:

• Use the AWS CLI to query real-time resource data

• Automate daily reporting using cron

• Write a simple shell script that makes API calls to AWS

“DevOps isn’t just about deploying code — it’s about automating visibility.”