Workspaces and Environments

Managing multiple environments (development, staging, production) is a core challenge in infrastructure as code. Terraform provides several approaches: workspaces, directory structures, and variable files. This lesson covers each approach and when to use them.

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Terraform Workspaces

Workspaces allow you to maintain multiple instances of state for the same configuration:

terraform workspace new staging
terraform workspace new production
terraform workspace list
terraform workspace select staging

How Workspaces Work

Each workspace has its own state file:

terraform.tfstate.d/
├── staging/
│   └── terraform.tfstate
└── production/
    └── terraform.tfstate

Using Workspaces in Configuration

Access the current workspace name with terraform.workspace:

resource "aws_instance" "web" {
  ami           = var.ami_id
  instance_type = terraform.workspace == "production" ? "t3.large" : "t3.micro"

  tags = {
    Environment = terraform.workspace
  }
}

Workspace Commands

Command	Purpose
terraform workspace list	List all workspaces
terraform workspace new <name>	Create a new workspace
terraform workspace select <name>	Switch to a workspace
terraform workspace delete <name>	Delete a workspace
terraform workspace show	Show the current workspace

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When to Use Workspaces

Good Fit	Poor Fit
Same infrastructure, different instances	Very different configurations per environment
Testing changes before promoting	Different providers or backends per environment
Short-lived environments	Teams that need strict isolation

Tip: Workspaces are best for lightweight environment separation. For production-grade isolation, consider directory-based environments or Terraform Cloud workspaces.

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Directory-Based Environments

A more explicit approach is to use separate directories for each environment:

infrastructure/
├── modules/
│   ├── network/
│   ├── compute/
│   └── database/
├── environments/
│   ├── development/
│   │   ├── main.tf
│   │   ├── variables.tf
│   │   ├── terraform.tfvars
│   │   └── backend.tf
│   ├── staging/
│   │   ├── main.tf
│   │   ├── variables.tf
│   │   ├── terraform.tfvars
│   │   └── backend.tf
│   └── production/
│       ├── main.tf
│       ├── variables.tf
│       ├── terraform.tfvars
│       └── backend.tf

Advantages

Advantage	Description
Full isolation	Each environment has its own state and backend
Different configurations	Environments can diverge when needed
Clear blast radius	A mistake in staging cannot affect production
Separate permissions	Different IAM roles per environment backend

Example: Environment-Specific Variables

environments/development/terraform.tfvars:

environment    = "development"
instance_type  = "t3.micro"
instance_count = 1
enable_ha      = false

environments/production/terraform.tfvars:

environment    = "production"
instance_type  = "t3.large"
instance_count = 3
enable_ha      = true