EC2 Start / Stop Automation (Python + AWS CLI)

Overview

This project is an AWS automation script built using Python, boto3, and AWS CLI.

It allows you to:

List all EC2 instances in your AWS account

View their current running state

Start an EC2 instance

Stop an EC2 instance

The goal of this project is to demonstrate practical AWS automation skills using both:

AWS SDK for Python (boto3)

AWS CLI executed through Python

This reflects how real cloud engineers automate infrastructure instead of relying on the AWS Console.

Technologies Used

Python 3

AWS SDK for Python (boto3)

AWS CLI

Bash commands executed via Python subprocess

IAM permissions for EC2 control

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How the Script Works

Python runs AWS CLI commands to list EC2 instances

Instance IDs and states are displayed

User selects whether to start or stop an instance

boto3 sends the start or stop request to AWS EC2

Check if running in AwsConsole:

Script Breakdown

1. AWS Configuration

REGION = "eu-north-1"
INSTANCE_ID = "ENTER_INSTANCE_ID"

Region must match where your EC2 instance exists

Instance ID must start with:

i-xxxxxxxxxxxxxxxxx

Reserved instance IDs (r-xxxx) will not work.

2. Listing EC2 Instances

def list_ec2():
    subprocess.run(
        "bash -c 'aws ec2 describe-instances --query Reservations[].Instances[].InstanceId --output text'",
        shell=True
    )

    subprocess.run(
        "bash -c 'aws ec2 describe-instances --query Reservations[].Instances[].State.Name --output text'",
        shell=True
    )

This uses the AWS CLI to:

Retrieve all EC2 instance IDs

Retrieve their current states

The --output text option removes JSON brackets and makes output readable.

3. Starting an Instance

def start_instance():
  ec2.start_instances(InstanceIds=[INSTANCE_ID])

This calls the AWS EC2 API:

StartInstances

Billing begins when the instance enters the running state.

4. Stopping an Instance

def stop_instance():
    ec2.stop_instances(InstanceIds=[INSTANCE_ID])

This calls:

StopInstances

Compute billing stops, but EBS storage costs remain.

5. Menu-Based CLI Interface

print("1 - Start instance")
print("2 - Stop instance")

User input determines which EC2 API call is executed.

Example Output

list of Ec2 instances
i-0a1b2c3d4e5f67890
i-09182736455443321

running
stopped

EC2 CONTROL

1 - Start instance
2 - Stop instance
Choose option (1 or 2):

Prerequisites

1. Python installed python --version

Recommended: Python 3.10+

2. Install dependencies

pip install boto3

4. AWS CLI installed

aws --version

6. Configure AWS credentials aws configure

You must configure:

Access Key ID

Secret Access Key

Default region

Output format (json or text)

Credentials are stored securely in:

~/.aws/credentials

No credentials are stored in this repository.

Required IAM Permissions

The AWS user or role must have the following permissions:

{
  "Effect": "Allow",
  "Action": [
    "ec2:DescribeInstances",
    "ec2:StartInstances",
    "ec2:StopInstances"
  ],
  "Resource": "*"
}

Without these permissions the script will fail.

Important AWS Concepts Demonstrated

EC2 lifecycle states

Difference between start and create

boto3 client usage

AWS CLI integration

IAM permissions

Region-specific resources

Infrastructure automation

Safety Notes

Starting an EC2 instance incurs cost

Stopping EC2 does not delete it

EBS volumes continue to incur storage charges

Terminated instances cannot be restarted

Learning Objectives

This project was built to practice:

Python automation

AWS SDK usage

CLI-to-Python integration

Cloud cost awareness

Infrastructure-as-code mindset

DevOps-style tooling

Possible Improvements

Future enhancements could include:

Automatic instance ID detection

State validation before start/stop

Display instance name tags

Tag-based instance selection

Lambda-based automation

Scheduled auto shutdown

Telegram or email notifications

Author

Siv, Learning cloud engineering through hands-on AWS automation.

GitHub: https://github.com/siv-the-programmer