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atmos scaffold validate

Validate a template's scaffold.yaml before it reaches a developer or CI. Validation checks the versioned manifest contract; generation then validates the answers supplied to that contract.

atmos scaffold validate --help

Usage​

atmos scaffold validate [path]
atmos scaffold validate
atmos scaffold validate ./scaffolds/terraform-component

Valid Manifest​

scaffold.yaml
apiVersion: atmos/v1
kind: AtmosScaffoldConfig
metadata:
  name: terraform-component
  description: Standard Terraform component
  version: 1.0.0
spec:
  fields:
    - name: component_name
      label: Component name
      type: input
      required: true
      validation:
        pattern: "^[a-z0-9-]+$"
        message: Use lowercase letters, digits, and hyphens.
    - name: region
      type: select
      options: [us-east-1, us-west-2]
      default: us-east-1
    - name: environments
      type: multiselect
      options: [dev, staging, prod]
      default: [dev]
    - name: enable_monitoring
      type: confirm
      default: false
    - name: alert_email
      type: input
      when: "answers.enable_monitoring == true"
  files:
    - path: monitoring.tf
      when: "answers.enable_monitoring == true"

The required manifest identity is apiVersion: atmos/v1, kind: AtmosScaffoldConfig, and metadata.name. metadata.description, metadata.author, and metadata.version are optional metadata. spec.values, spec.source, and spec.baseRef are normally persisted by generation to record answers and provenance for updates.

What Validation Checks​

  • Manifest identity, YAML shape, field names, supported field types, and field-specific options.
  • The when: representation: a predicate/CEL string or list is valid; map-style {all, any, not} conditions are rejected for scaffold manifests.
  • Regex syntax in validation.pattern and structural constraints in the generated JSON Schema.
  • Conditional file entries and the step-backed hook configuration shape.

atmos scaffold validate checks template configuration. atmos scaffold generate additionally checks concrete answers: required text, select/multiselect options, boolean coercion, and regex matches across prompts, defaults, persisted values, and --set flags.

Common Fixes​

Use spec.fields, not the retired prompts: key:

# Invalid
prompts:
  - name: component_name
    type: input

# Valid
spec:
  fields:
    - name: component_name
      type: input

Declare options as scalar values and use a boolean comparison in CEL:

spec:
  fields:
    - name: enabled
      type: confirm
    - name: environment
      type: select
      options: [dev, prod]
      when: "answers.enabled == true"

CI Validation​

.github/workflows/validate-scaffolds.yml
name: Validate scaffolds

on: [push, pull_request]

jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Validate templates
        run: |
          for manifest in scaffolds/*/scaffold.yaml; do
            atmos scaffold validate "$(dirname "$manifest")"
          done

Follow validation with a dry run and representative --set values:

atmos scaffold validate ./scaffolds/terraform-component
atmos scaffold generate ./scaffolds/terraform-component ./test-output \
  --defaults --set component_name=vpc --dry-run --skip-hooks