Subcomponents Reference

Catalog Representation

Subcomponents are defined in the parent component's catalog-info.yaml as an object array at spec.components[]. Each entry contains the metadata defining the subcomponent, and in the Builder it is treated as part of the parent component entity defintion, not as a separate catalog entity.

For lifecycle context, see Subcomponents. Marketplace and access attributes are described in Shoppable and Consumable attributes.

Fields

The minimum set of fields needed for each subcomponent are as follows:

Field	Type	Author input	Descriptor behavior
name	string	Required	Subcomponent name, unique within the parent component; appended to the parent component URN to generate the subcomponent id.
kind	string	Required	Subcomponent resource type identifier used in the descriptor.
infrastructureTemplateId	string	Required	Identifies the Tech Adapter for the subcomponent.
consumable	boolean	Required	Consumable attribute of the subcomponent.
shoppable	boolean	Optional	Shoppable attribute, when supplied.

The id of each component is automatically generated by Witboost as <parent component id>:<subcomponent name>, overwriting any supplied value.

Parent Catalog Example

The following is example of a complete component catalog-info.

apiVersion: witboost.com/v1
kind: Component
metadata:
  name: finance:invoice:0:invoice-storage
  description: Storage for invoice data
spec:
  type: storage
  lifecycle: experimental
  owner: group:default/finance
  system: system:default/finance:invoice:0
  mesh:
    name: Invoice storage
    version: "0.0.0"
    useCaseTemplateId: urn:dmb:utm:invoice-storage-template:0.0.0
    infrastructureTemplateId: urn:dmb:itm:storage-adapter:1
    consumable: false
    shoppable: true
    technology: object-storage
    region: eu-west-1
  components:
    - name: invoices
      kind: outputport
      infrastructureTemplateId: urn:dmb:itm:invoice-table-adapter:1
      consumable: true
      shoppable: true
      region: eu-central-1
      tableName: invoices

Another example of using subcomponents to define a complex component like a data contract can be seen here.

Descriptor Mapping

The parent catalog entity's spec.components[] becomes components[] at the root of its component descriptor. This is distinct from the project descriptor's list of top-level component descriptors; see Descriptors.

With inheritance enabled, the example above produces the following subcomponent entry in the parent component descriptor's components field:

components:
  - id: urn:dmb:cmp:finance:invoice:0:invoice-storage:invoices
    name: invoices
    kind: outputport
    infrastructureTemplateId: urn:dmb:itm:invoice-table-adapter:1
    consumable: true
    shoppable: true
    version: "0.0.0"
    useCaseTemplateId: urn:dmb:utm:invoice-storage-template:0.0.0
    technology: object-storage
    region: eu-central-1
    tableName: invoices

The child region overrides the parent's value. The version, useCaseTemplateId, and technology fields come from the parent's spec.mesh. The generated ID uses the parent component URN urn:dmb:cmp:finance:invoice:0:invoice-storage and the child name invoices.

Inheritance Configuration

Field inheritance is configured via ui.appConfig.mesh.builder.editAndTest.subcomponents.inheritFromParent, to inherit the parent spec.mesh properties into each subcomponent descriptor.

ui:
  appConfig:
    mesh:
      builder:
        editAndTest:
          subcomponents:
            inheritFromParent: true

When true, eligible properties from the parent's spec.mesh are copied first, then the subcomponent's direct fields override matching properties. The generated id is applied last regardless of this setting. When false, no parent properties are inherited; the subcomponent's direct fields and generated id still populate its descriptor.

The following parent properties are excluded from inheritance:

• id
• components
• consumable
• shoppable
• name
• infrastructureTemplateId
• kind
• dependsOn
• __dataContractEnabled
• __dataContractGuardianSpec
• readsFrom

These exclusions affect only inheritance from the parent. They do not remove fields explicitly supplied on a subcomponent.