Test Environment Management

Core Principle

Unstable test environments = unreliable tests.

Test environment management ensures consistent, reproducible environments for testing while optimizing cost and maintenance.

Environment Types

Local Development

Developer machine
- Fast feedback
- Full control
- May differ from production

CI Environment

GitHub Actions, Jenkins, etc.
- Automated tests
- Ephemeral (created per build)
- Must match production closely

Staging/QA Environment

Pre-production mirror
- Integration testing
- User acceptance testing
- Should match production exactly

Production (Testing in Prod)

Real environment
- Canary deployments
- Feature flags
- Synthetic monitoring

Docker for Test Environments

Containerize test dependencies:

# docker-compose.test.yml
version: '3.8'

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      NODE_ENV: test
      DATABASE_URL: postgres://postgres:password@db:5432/test
    depends_on:
      - db
      - redis

  db:
    image: postgres:15
    environment:
      POSTGRES_DB: test
      POSTGRES_PASSWORD: password
    ports:
      - "5432:5432"

  redis:
    image: redis:7
    ports:
      - "6379:6379"

Run tests in container:

docker-compose -f docker-compose.test.yml up -d
docker-compose -f docker-compose.test.yml exec app npm test
docker-compose -f docker-compose.test.yml down

Infrastructure as Code

Terraform for test environments:

# test-environment.tf
resource "aws_instance" "test_server" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.medium"

  tags = {
    Name        = "test-environment"
    Environment = "test"
    AutoShutdown = "20:00" # Cost optimization
  }
}

resource "aws_rds_instance" "test_db" {
  allocated_storage = 20
  engine           = "postgres"
  engine_version   = "15"
  instance_class   = "db.t3.micro"
  db_name          = "test"
  username         = "testuser"
  password         = var.db_password

  backup_retention_period = 0 # No backups needed for test
  skip_final_snapshot    = true
}

Service Virtualization

Mock external services:

// Use WireMock for API mocking
import { WireMock } from 'wiremock-captain';

const wiremock = new WireMock('http://localhost:8080');

// Mock payment gateway
await wiremock.register({
  request: {
    method: 'POST',
    url: '/charge'
  },
  response: {
    status: 200,
    jsonBody: {
      transactionId: '12345',
      status: 'approved'
    }
  }
});

// Tests use mock instead of real gateway

Environment Parity

Dev/Prod Parity Checklist:

• Same OS and versions
• Same database type and version
• Same dependency versions
• Same configuration structure
• Same environment variables

12-Factor App principles for parity

Cost Optimization

Auto-shutdown test environments:

# Shutdown test environments after hours
0 20 * * * aws ec2 stop-instances --instance-ids $(aws ec2 describe-instances --filters "Name=tag:Environment,Values=test" --query "Reservations[].Instances[].InstanceId" --output text)

# Start before work hours
0 7 * * 1-5 aws ec2 start-instances --instance-ids $(aws ec2 describe-instances --filters "Name=tag:Environment,Values=test" --query "Reservations[].Instances[].InstanceId" --output text)

Use spot instances for test workloads:

resource "aws_instance" "test_runner" {
  instance_type        = "c5.2xlarge"
  instance_market_options {
    market_type = "spot"
    spot_options {
      max_price = "0.10" # Save 70% vs on-demand
    }
  }
}

Related Skills

• test-data-management
• continuous-testing-shift-left
• test-automation-strategy

Remember

Environment inconsistency = flaky tests.

"Works on my machine" problems from:

• Different OS/versions
• Missing dependencies
• Configuration differences
• Data differences

Infrastructure as Code ensures repeatability.

With Agents: Agents automatically provision test environments, ensure parity with production, and optimize costs by auto-scaling and auto-shutdown.