1. Variable Fundamentals
Terraform variables (.tfvars files) define values that drive your infrastructure configuration. Proper structure ensures maintainability and security.
terraform {
required_version = ">= 1.3.0"
}
provider "aws" {
region = var.region
}
resource "aws_instance" "example" {
ami = var.ami_id
instance_type = var.instance_type
}
Variables are declared in terraform.tfvars (auto-detected) or .tfvars files (manual load). Sensitive values should never be hardcoded.
2. Secure Management
Recommended Pattern
# terraform.tfvars region = "us-west-1" ami_id = "ami-12345678"
Use auto-detected terraform.tfvars for local development values
Avoid This:
# secrets.tfvars access_key = "your-long-access-key-here" secret_key = "your-secret-123456"
Never commit tfvars files with sensitive data. Use TF_VAR_env_vars instead
3. Best Practice Patterns
Immutable Values
Use variables to define environment-agnostic values that change between deployments.
Type Constraints
Define variable types in variables.tf to prevent unexpected input errors during runtime.
Sensitive Handling
Mark sensitive arguments with sensitive = true to suppress their visibility in logs.
Ready to Implement?
Download a sample .tfvars file and start structuring your variables with confidence.
Download Sample .tfvars