Terraform Tutorial — Workspace Interpolation

The built-in terraform.workspace variable returns the name of the current workspace. Use it to differentiate resources across environments.

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Basic Usage

resource "aws_s3_bucket" "app" {
  bucket = "myapp-${terraform.workspace}-assets"
}

Workspace	Bucket Name
dev	myapp-dev-assets
staging	myapp-staging-assets
prod	myapp-prod-assets

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Conditional Sizing

Use workspace names to control resource sizes:

locals {
  instance_types = {
    dev     = "t3.micro"
    staging = "t3.small"
    prod    = "t3.large"
  }

  instance_counts = {
    dev     = 1
    staging = 2
    prod    = 5
  }
}

resource "aws_instance" "web" {
  count         = local.instance_counts[terraform.workspace]
  ami           = data.aws_ami.amazon_linux.id
  instance_type = local.instance_types[terraform.workspace]

  tags = {
    Name        = "web-${terraform.workspace}-${count.index + 1}"
    Environment = terraform.workspace
  }
}

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Tagging with Workspace

locals {
  common_tags = {
    Environment = terraform.workspace
    ManagedBy   = "terraform"
    Project     = "myapp"
  }
}

resource "aws_vpc" "main" {
  cidr_block = var.vpc_cidr

  tags = merge(local.common_tags, {
    Name = "myapp-${terraform.workspace}-vpc"
  })
}

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Backend Key with Workspace

Remote backends automatically separate state by workspace:

# S3 backend stores state at:
# s3://bucket/env:/dev/terraform.tfstate
# s3://bucket/env:/staging/terraform.tfstate
# s3://bucket/env:/prod/terraform.tfstate

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What’s Next?

Workspaces aren’t always the right tool. Let’s compare workspaces vs separate directories.

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← Workspace Commands Workspaces vs Directories →