Modern Cloud Infrastructure as Code with Sceptre: Building and Deploying a Simple Python Web Service

This content originally appeared on DEV Community and was authored by Mohammad Fuzail

As cloud-native architectures become the norm, managing infrastructure as code (IaC) is no longer a luxury, it’s a necessity. While tools like the Serverless Framework are popular for abstracting infrastructure, Sceptre stands out for its tight integration with AWS CloudFormation and its flexibility in complex, real-world use cases.

In this post, we’ll:

• Use Sceptre to provision infrastructure
• Build a simple Python service
• Containerize it with Docker
• Set up Jenkins for CI/CD
• Briefly explore why Sceptre may be preferable to the Serverless Framework

Why Sceptre over Serverless Framework?

Sceptre is especially suited for teams who:

• Need infrastructure flexibility (beyond Lambda/APIs)
• Want full access to AWS resource definitions
• Deploy to multiple environments (dev, test, prod) in a structured way

Step 1: Write a Simple Python Script

Here’s the application logic — a basic Python script to be run in the cloud:

#script.py
import time

print("Python task started...")
time.sleep(3)
print("Task completed successfully!")

Use cases:

• Automation tasks
• Data processing
• Scheduled jobs
• Infrastructure hooks

Step 2: Dockerize It

To run this in ECS, we need to containerize the script:

# Dockerfile
FROM python:3.10-slim

WORKDIR /app
COPY script.py .

CMD ["python", "script.py"]
Build and test:
docker build -t python-task .
docker run python-task

Step 3: Use Sceptre to Deploy to ECS Fargate

Sceptre lets us manage AWS infrastructure using CloudFormation templates and environment-specific configurations.

Directory Structure
infra/
├── config/
│ └── dev/
│ └── python-task.yaml
└── templates/
└── ecs-task.yaml

#config/dev/python-task.yaml
template_path: templates/ecs-task.yaml
stack_name: python-task
parameters:
  TaskName: python-script-task
  ContainerImage: <YOUR_ECR_IMAGE_URL>

templates/ecs-task.yaml (CloudFormation)
Resources:
  TaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      Family: !Ref TaskName
      Cpu: '256'
      Memory: '512'
      RequiresCompatibilities: [FARGATE]
      NetworkMode: awsvpc
      ExecutionRoleArn: arn:aws:iam::<ACCOUNT_ID>:role/ecsTaskExecutionRole
      ContainerDefinitions:
        - Name: python-container
          Image: !Ref ContainerImage
          Essential: true
          LogConfiguration:
            LogDriver: awslogs
            Options:
              awslogs-group: /ecs/python-task
              awslogs-region: !Ref AWS::Region
              awslogs-stream-prefix: python-task

Deploy with Sceptre :

cd infra
sceptre launch dev/python-task.yaml

Once launched, you can run this task using AWS CLI or trigger it via EventBridge for scheduled executions.

Step 4: Automate Deployment with Jenkins

Here’s a minimal Jenkinsfile to automate the entire flow:

pipeline {
  agent any
  environment {
    ECR_REPO = "<ACCOUNT_ID>.dkr.ecr.<REGION>.amazonaws.com/python-task"
  }
  stages {
    stage('Build') {
      steps {
        sh 'docker build -t python-task .'
      }
    }
    stage('Push to ECR') {
      steps {
        sh '''
          aws ecr get-login-password | docker login --username AWS --password-stdin $ECR_REPO
          docker tag python-task:latest $ECR_REPO:latest
          docker push $ECR_REPO:latest
        '''
      }
    }
    stage('Deploy Infra') {
      steps {
        dir('infra') {
          sh 'sceptre launch dev/python-task.yaml'
        }
      }
    }
  }
}

One push to Git, and Jenkins takes care of:

• Building your container
• Publishing it to ECR
• Updating your ECS TaskDefinition via Sceptre

Summary

You now have a repeatable, production-grade deployment pattern for running Python tasks in AWS with full control and no unnecessary abstraction.
Sceptre is not a replacement for Serverless Framework, but an empowering alternative when you want low-level control and native AWS CloudFormation integration. For teams who treat infrastructure as a first-class citizen, Sceptre is a great fit.

Useful References :

• Sceptre Documentation
• Docker Basics
• AWS ECS Task Definition Docs
• Jenkins Pipeline Docs
• AWS CLI: Run ECS Task

Disclaimer: This is a personal blog. The views and opinions expressed here are only those of the author and do not represent those of any organization or any individual with whom the author may be associated, professionally or personally.

This content originally appeared on DEV Community and was authored by Mohammad Fuzail