YAML Functions in Locals

Locals now support YAML functions like !env, !exec, !store, !terraform.state, and !terraform.output.

The Feature

Locals can now use all Atmos YAML functions to fetch dynamic values:

• !env - Environment variables
• !exec - Command execution
• !store - Store lookups
• !terraform.state - Terraform state queries
• !terraform.output - Terraform outputs from other components

Example with Environment Variables

locals:
  api_endpoint: !env API_ENDPOINT
  api_url: "https://{{ .locals.api_endpoint }}/api/v1"

components:
  terraform:
    myapp:
      vars:
        api_url: "{{ .locals.api_url }}"

Example with Terraform State

locals:
  # Fetch from another component's terraform state
  vpc_id: !terraform.state vpc .vpc_id
  subnet_ids: !terraform.state vpc .private_subnet_ids

components:
  terraform:
    eks:
      vars:
        vpc_id: "{{ .locals.vpc_id }}"
        subnet_ids: "{{ .locals.subnet_ids }}"

Example with Store

locals:
  db_password: !store secrets/database .password
  connection_string: "postgresql://app:{{ .locals.db_password }}@db.example.com/mydb"

components:
  terraform:
    backend:
      vars:
        database_url: "{{ .locals.connection_string }}"

How It Works

1. YAML functions in locals are processed during stack configuration loading
2. The resolved values are available to other locals and component vars
3. Locals can combine YAML function results with Go templates

Use Cases

• Environment-specific configuration: Use !env to inject environment-specific values
• Cross-component references: Use !terraform.state to reference outputs from other components
• Secret management: Use !store to fetch secrets from your configured store
• Dynamic values: Use !exec to run commands and capture output

Upgrade

Upgrade Atmos to get this feature. Existing locals configurations continue to work unchanged.

References

• Locals Documentation
• YAML Functions Documentation