Annotator custom action for Scaffolder Backstage

The annotator module for @backstage/plugin-scaffolder-backend.

This module allows users to create custom actions for annotating their entity objects. Additionally, it enables users to utilize existing custom actions provided by the module for annotating entities with timestamps and scaffolder entity references.

Installation

Available custom actions

| Action | Description | | ------------------------- | :-----------------------------------------------------------------------------------------------------: | | catalog:timestamping | Adds the backstage.io/createdAt annotation containing the current timestamp to your entity object | | catalog:scaffolded-from | Adds scaffoldedFrom spec containing the template entityRef to your entity object | | catalog:annotate | Allows you to annotate your entity object with specified label(s), annotation(s) and spec property(ies) |

To begin, install the module package into the backend workspace of your backstage instance:

yarn workspace backend add @janus-idp/backstage-scaffolder-backend-module-annotator

Registering the annotator action plugin with the new backend system

To install the module into the new backend system, add the following into the packages/backend/src/index.ts file:

const backend = createBackend();

// highlight-add-start
backend.add(
  import('@janus-idp/backstage-scaffolder-backend-module-annotator/alpha'),
);
// highlight-add-end

backend.start();

Registering the annotator action plugin with the legacy backend system

1. Register the custom actions in the packages/backend/src/plugins/scaffolder.ts file:

• Install the @backstage/integration package using the following command:

  yarn workspace backend add @backstage/integration

• Add the createTimestampAction, createScaffoldedFromAction and createAnnotatorAction with the other built-in actions:

  
  import { CatalogClient } from '@backstage/catalog-client';
  /* highlight-add-start */
  import { ScmIntegrations } from '@backstage/integration';
  import {
  createBuiltinActions,
  createRouter,
  } from '@backstage/plugin-scaffolder-backend';
  import { createTimestampAction, createScaffoldedFromAction, createAnnotatorAction } from '@janus-idp/backstage-scaffolder-backend-module-annotator';
  /* highlight-add-end */
  ...
  
  export default async function createPlugin(
  const catalogClient = new CatalogClient({
    discoveryApi: env.discovery,
  });
  
  /* highlight-add-start */
  const integrations = ScmIntegrations.fromConfig(env.config);
  
  const builtInActions = createBuiltinActions({
    integrations: integrations as any,
    catalogClient,
    config: env.config,
    reader: env.reader,
  });
  const actions = [...builtInActions, createTimestampAction(), createScaffoldedFromAction(), createAnnotatorAction()];
  /* highlight-add-end */
  
  
  return await createRouter({
    /* highlight-add-next-line */
    actions,
    logger: env.logger,
    ...
  });

2. To annotate the catalog-info.yaml skeleton with the current timestamp, add the catalog:timestamping custom action in your template's YAML file after the Fetch Skeleton + Template step. Refer to the example templates for examples on how it's used in a template.

steps:
  - id: template
    name: Fetch Skeleton + Template
    action: fetch:template
    ...

  # highlight-add-start
  - id: timestamp
    name: Add Timestamp to catalog-info.yaml
    action: catalog:timestamping
  # highlight-add-end

3. To annotate the catalog-info.yaml skeleton with the template's entityRef, add the catalog:scaffolded-from custom action in your YAML file after the Fetch Skeleton + Template step. Refer to the example templates for examples on how it is used in a template.

steps:
  - id: template
    name: Fetch Skeleton + Template
    action: fetch:template
    ...
  # highlight-add-start
  - id: append-templateRef
    name: Append the entityRef of this template to the entityRef
    action: catalog:scaffolded-from
  # highlight-add-end

4. To use the catalog:annotate action to annotate your entity object. Refer to the example templates for examples on how it is used in a template.

steps:
  - id: template
    name: Fetch Skeleton + Template
    action: fetch:template
    ...
  # highlight-add-start
  - id: add-fields-to-catalog-info
    name: Add a few fields into `catalog-info.yaml` using the generic action
    action: catalog:annotate
    input:
      labels:
        custom: ${{ parameters.label }}
        other: "test-label"
      annotations:
        custom.io/annotation: ${{ parameters.label }}
        custom.io/other: "value"
  # highlight-add-end

Creating custom actions for your templates using the annotator module

Create the custom action

The createAnnotatorAction action accepts the following parameters:

| Parameter Name | Type | Required | Description | | ---------------------------------- | :------: | :------: | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | actionId | string | Yes | A unique id for the action. Default: catalog:annotate, please provide one or else it may conflict with the generic catalog:annotate custom action that is provided by this module. | | actionDescription | string | No | A description of what the action accomplishes. Default: "Creates a new scaffolder action to annotate the entity object with specified label(s), annotation(s) and spec property(ies)." | | loggerInfoMsg | string | No | A message that will be logged upon the execution of the action. Default: "Annotating your object" | | annotateEntityObject.labels | object | No | Key-value pairs to be added to the metadata.labels of the entity | | annotateEntityObject.annotations | object | No | Key-value pairs to be added to the metadata.annotations of the entity | | annotateEntityObject.spec | object | No | Key-value pairs to be added to the spec of the entity. The value for each key can either be a string or an object with the key readFromContext, enabling users to specify the path in the context from which the value should be retrieved. |

1. Create your custom action

2. Add the annotator module package @janus-idp/backstage-scaffolder-backend-module-annotator into your module's package.json

3. In the action file, add the following snippet to it:

// highlight-add-start
import { createAnnotatorAction } from '@janus-idp/backstage-scaffolder-backend-module-annotator';

export const createAddCompanyTitleAction = () => {
  return createAnnotatorAction(
    'catalog:company-title',
    'Creates a new `catalog:company-title` Scaffolder action to annotate scaffolded entities with the company title.',
    'Annotating catalog-info.yaml with the company title',
  );
};
// highlight-add-end

4. Install the custom action into your backstage instance following steps similar to the installation instructions above

Use your custom action in your desired template(s)

The annotator template action accepts the following inputs

Input

| Parameter Name | Type | Required | Description | | ---------------- | :------: | :------: | ------------------------------------------------------------------------------------------------------------------ | | labels | object | No | Key-value pairs to be added to the metadata.labels of the entity | | annotations | object | No | Key-value pairs to be added to the metadata.annotations of the entity | | spec | object | No | Key-value pairs to be added to the spec of the entity | | entityFilePath | string | No | The file path from which the YAML representation of the entity should be read | | objectYaml | object | No | The YAML representation of the object/entity | | writeToFile | string | No | The file path where the YAML representation of the entity should be stored. Default value is './catalog-info.yaml' |

Output

| Name | Type | Description | | ----------------- | :------: | -------------------------------------------------------------------------------------------- | | annotatedObject | object | The entity object marked with your specified annotation(s), label(s), and spec property(ies) |

To annotate the entity file, add your custom action to your template file after Fetch Skeleton + Template step. Please note that your custom action needs to be installed into the backstage instance running the software template.

// highlight-add-start
- id: company-title
  name: Add company title to catalog-info.yaml
  action: catalog:company-title
  input:
    labels: {
      company: 'My Company'
    }
// highlight-add-end