AWS Terraform Blue-Green Deployment Using Elastic Beanstalk

Source: Dev.to | Jan 11, 2026 (UTC)

Introduction:

In a traditional approach to application deployment, you typically fix a failed deployment by redeploying an earlier, stable version of the application. Redeployment in traditional data centers is typically done on the same set of resources due to the cost and effort of provisioning additional resources. Although this approach works, it has many shortcomings. Rollback isn’t easy because it’s implemented by redeployment of an earlier version from scratch. This process takes time, making the application potentially unavailable for long periods. Even in situations where the application is only impaired, a rollback is required, which overwrites the faulty version. As a result, you have no opportunity to debug the faulty application in place.

Applying the principles of agility, scalability, utility consumption, as well as the automation capabilities of Amazon Web Services can shift the paradigm of application deployment. This enables a better deployment technique called blue/green deployment.

Blue/Green Deployment Methodology:

Blue/green deployments provide releases with near zero-downtime and rollback capabilities. The fundamental idea behind blue/green deployment is to shift traffic between two identical environments that are running different versions of your application. The blue environment represents the current application version serving production traffic. In parallel, the green environment is staged running a different version of your application. After the green environment is ready and tested, production traffic is redirected from blue to green. If any problems are identified, you can roll back by reverting traffic back to the blue environment.

Architecture diagram

Benefits of Blue/Green Deployment:

1. Zero Downtime: Seamless traffic transition ensures uninterrupted service.
2. Safe Rollbacks: Easy reversion to the Blue environment if issues arise.
3. Efficient Testing: Allows comprehensive testing of the new environment without affecting live users.
4. Scalability: Works well for both monolithic and microservices architectures.

AWS Elastic Beanstalk:

AWS Elastic Beanstalk performs an in-place update when you update your application versions, your application might become unavailable to users for a short period of time. To avoid this, perform a blue/green deployment. To do this, deploy the new version to a separate environment, and then swap the CNAMEs of the two environments to redirect traffic to the new version instantly.

To validate this approach, I tested and deployed Blue-Green Deployment with javascript application, This hands-on implementation ensured real-world feasibility and reliability.

Project Highlights:

• Tech Stack: Terraform, Elastic Beanstalk, EC2, S3.
• Goal: Achieve zero downtime while updating my application.
• Key Challenges: Ensuring that visitors never experience an outage during deployments.
• Solution: Implementing Blue-Green Deployment using Elastic Beanstalk and EC2.

Project Structure
My project is structured in the following way:

Day-17/ ├── Readme.md ├── Assets/ └── terraform/ ├── .terraform/ ├── .terraform.lock.hcl ├── app-v1/ │ ├── app.js │ ├── package.json │ └── app-v1.zip ├── app-v2/ │ ├── app.js │ ├── package.json │ └── app-v2.zip ├── blue-environments.tf ├── green-environments.tf ├── main.tf ├── outputs.tf ├── package-apps.ps1 ├── package-apps.sh ├── swap-environments.ps1 ├── swap-environments.sh ├── terraform.tfstate ├── terraform.tfstate.backup ├── terraform.tfvars.example └── variables.tf

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