Metadata Inheritance

Metadata now inherits from base components, just like vars and settings.

The Problem

When managing infrastructure at scale, you want to enforce consistent governance policies across your components. Pin all instances to the same component version. Lock critical infrastructure to prevent accidental changes. Use standardized workspace naming patterns. Document component ownership.

But before this release, metadata didn't inherit from base components. Even though you could inherit vars and settings, you had to copy-paste metadata configuration to every derived component:

# You defined governance once...
vpc/defaults:
  metadata:
    type: abstract
    component: vpc/v2                                             # Pin to version
    locked: true
    terraform_workspace_pattern: "{tenant}-{environment}-{stage}"
    custom:
      description: "Virtual Private Cloud network configuration"
      owner: "platform-team"

# ...but had to repeat EVERYTHING for each instance
vpc/primary:
  metadata:
    inherits: [vpc/defaults]
    component: vpc/v2                                             # Repeated
    locked: true                                                  # Repeated
    terraform_workspace_pattern: "{tenant}-{environment}-{stage}" # Repeated
    custom:                                                       # Repeated
      description: "Virtual Private Cloud network configuration"  # Repeated
      owner: "platform-team"                                      # Repeated

vpc/secondary:
  metadata:
    inherits: [vpc/defaults]
    component: vpc/v2                                             # Repeated again
    locked: true                                                  # Repeated again
    terraform_workspace_pattern: "{tenant}-{environment}-{stage}" # Repeated again
    custom:                                                       # Repeated again
      description: "Virtual Private Cloud network configuration"  # Repeated again
      owner: "platform-team"                                      # Repeated again

The biggest pain? When upgrading to vpc/v3, you had to update the component version in every single instance. Miss one, and you'd have components running different versions with no indication why.

The Solution

Now it just works:

vpc/defaults:
  metadata:
    type: abstract
    component: vpc/v2                                             # Define version once
    locked: true
    terraform_workspace_pattern: "{tenant}-{environment}-{stage}"
    custom:
      description: "Virtual Private Cloud network configuration"
      owner: "platform-team"

vpc/primary:
  metadata:
    inherits: [vpc/defaults]
    # component, locked, terraform_workspace_pattern, and custom are all inherited

vpc/secondary:
  metadata:
    inherits: [vpc/defaults]
    # All governance settings inherited - no repetition needed

Want to upgrade to vpc/v3? Change it once in vpc/defaults, and all instances inherit the new version automatically.

Two fields are excluded from inheritance:

• metadata.inherits - defines the inheritance relationship itself
• metadata.type - component type is per-component (e.g., abstract shouldn't propagate to derived components)

Configuration

Metadata inheritance is now enabled by default. If this causes issues with existing configurations, you can disable it:

# atmos.yaml
stacks:
  inherit:
    metadata: false

See the inheritance documentation for details.