Ephemeral Environments: Replace Staging with On-Demand Previews

Ephemeral environments are temporary setups used in software development and testing that mimic production environments. These environments are created on-demand and are destroyed after use, promoting a more dynamic, flexible, and cost-effective approach to software development and testing. This guide delves into the concept of ephemeral environments, their benefits, and how to implement them using Infrastructure as Code (IaC) with tools like Terraform, Kubernetes, and GitHub Actions.

Ephemeral environments are short-lived and are typically spun up for a single purpose, such as testing a feature branch, running integration tests, or conducting performance testing. Unlike static environments, which are long-standing and often shared among multiple features or teams, ephemeral environments are created on-demand and disposed of once their purpose is served, ensuring a clean, isolated, and consistent environment for every test or development task.

- **Isolation:** Each task or feature is tested in a separate environment, reducing the risk of conflicts and interferences. - **Resource Efficiency:** Resources are only consumed when needed, allowing for better utilization and lowering costs. - **Faster Feedback Loops:** Developers and testers receive immediate feedback on their work, accelerating the development process. - **Reproducibility:** The environment can be replicated easily, ensuring consistency across development, testing, and production. - **Scalability:** New environments can be spun up as needed, scaling with the demands of the project or team.

IaC is a key enabler for ephemeral environments. It allows the entire infrastructure to be defined and managed through code, making it easy to create, duplicate, and destroy infrastructure components on demand.

Terraform is an open-source tool created by HashiCorp that allows users to define and provision infrastructure using a high-level configuration language. It supports multiple cloud providers and services, making it an ideal tool for creating ephemeral environments.

Kubernetes is an open-source container orchestration system for automating software deployment, scaling, and management. It's highly compatible with ephemeral environments, especially when managing containerized applications.

Implementing ephemeral environments involves several steps, from defining the infrastructure as code to integrating it into the CI/CD pipeline for automatic creation and destruction.

Start by defining your infrastructure with Terraform. This involves creating Terraform configuration files that specify the required resources for your environment.

provider "aws" {
  region = "us-west-2"
}

resource "aws_eks_cluster" "example" {
  name     = "example-cluster"
  role_arn = aws_iam_role.example.arn

  vpc_config {
    subnet_ids = aws_subnet.example[*].id
  }

  depends_on = [
    aws_iam_role_policy_attachment.example,
  ]
}

This example creates an Amazon EKS (Elastic Kubernetes Service) cluster using AWS as the provider. You would replace the placeholders with actual values specific to your project.

Integrating ephemeral environments into your CI/CD pipeline automates their creation and destruction based on the pipeline's stages or actions.

GitHub Actions can automate the process of creating and destroying ephemeral environments using Terraform. Here's how you can set up a workflow:

name: 'Terraform'

on:
  push:
    branches:
      - main
  pull_request:

jobs:
  terraform:
    name: 'Terraform'
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v2

    - name: Setup Terraform
      uses: hashicorp/setup-terraform@v1
      with:
        terraform_version: 0.13.0

    - name: Terraform Init
      run: terraform init

    - name: Terraform Plan
      run: terraform plan

    - name: Terraform Apply
      run: terraform apply -auto-approve

    - name: Cleanup
      if: ${{ github.event_name == 'pull_request' && github.event.action == 'closed' }}
      run: terraform destroy -auto-approve\

This GitHub Actions workflow initializes Terraform, applies the Terraform configuration when code is pushed to the main branch or a pull request is made, and destroys the environment when a pull request is closed.

Once your infrastructure is provisioned, Kubernetes can be used to deploy and manage the containers that make up your application within the ephemeral environments.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: example-app
  labels:
    app: example
spec:
  replicas: 3
  selector:
    matchLabels:
      app: example
  template:
    metadata:
      labels:
        app: example
    spec:
      containers:
      - name: example-app
        image: example/app:latest
        ports:
        - containerPort: 80

This Kubernetes deployment file specifies a deployment named `example-app` with three replicas, using the `example/app:latest` Docker image.

Ephemeral environments can lead to significant cost savings by:

- Reducing the need for permanent resources. - Allowing for more precise scaling, ensuring you only pay for what you use. - Decreasing the maintenance cost associated with long-lived environments.

Ephemeral environments, enabled by IaC and integrated into CI/CD pipelines, offer a flexible, efficient, and cost-effective solution for development and testing. By leveraging Terraform for infrastructure management, Kubernetes for container orchestration, and GitHub Actions for automation, teams can achieve faster feedback loops, better resource utilization, and higher quality software delivery.