Introduction to Immutable Infrastructure

Immutable infrastructure is a paradigm in the DevOps world where servers are never modified after they’re deployed. If something needs to be updated, fixed, or modified in any way, new servers are built from a common image with the necessary changes, and the old ones are discarded. This approach contrasts with the traditional method of continuously updating existing servers.

Why Immutable Infrastructure?

Immutable infrastructure offers several benefits:

  • Consistency: Since every server is created from the same image, you can expect the same behavior from all of them.
  • Reliability: If a server fails, you can replace it quickly with a new one that you know will work.
  • Scalability: It’s easy to add more servers when they’re all the same.
  • Security: Immutable servers are more secure because they’re less prone to configuration drift and unauthorized changes.

How to Create an Immutable Infrastructure

Creating an immutable infrastructure involves the following steps:

1. Define the Server Image

This is the blueprint for your servers. It should include the operating system, the application to be run, and any necessary configurations. You can use tools like Docker or Packer to create your server images.

2. Automate the Deployment

Use a tool like Terraform or CloudFormation to automate the deployment of your servers. This ensures that every server is created exactly the same way.

3. Implement Continuous Integration/Continuous Deployment (CI/CD)

CI/CD practices are crucial for maintaining an immutable infrastructure. They allow you to automatically build, test, and deploy your server images whenever changes are made to the codebase.

4. Monitor Your Infrastructure

Use monitoring tools to keep an eye on your servers and ensure they’re performing as expected. If a server fails, it should be replaced immediately.


Immutable infrastructure is a powerful concept that can greatly improve the reliability, scalability, and security of your applications. By following the steps outlined in this tutorial, you can start reaping the benefits of this approach.

For more detailed information on creating an immutable infrastructure, check out this book on Infrastructure as Code by Kief Morris.