Backstage – Transformando e Reutilizando variáveis em seu template com uma action customizada #helpdev-blog

1)_template.js

// The action
// path: packages/backend/src/plugins/scaffolder/actions

import { CatalogApi } from '@backstage/catalog-client';
import { parseEntityRef } from '@backstage/catalog-model';
import { 
  createTemplateAction,
 } from '@backstage/plugin-scaffolder-backend';


export const recoveryVariables = (catalogClient: CatalogApi) => {
  const catalog = catalogClient;
  // create your inputs
  return createTemplateAction<{ name: string; squad: string; type: string }>({
    id: 'helpdev:template:variables',
    schema: {
      input: {
        required: ['squad', 'name', 'type'],
        type: 'object',
        properties: {
          name: {
            type: 'string',
            title: 'Project Name',
          }, 
          squad: {
            type: 'string',
            title: 'Squad Name',
          }, 
          type: {
            type: 'string',
            title: 'Project Type',
          },          
        },
      },
    },
    
    async handler(ctx) {
      // find owners (squad/tribe/vertical)
      const squadName = ctx.input.squad;
      const squadRef = parseEntityRef({kind: "Group", namespace: "default", name: squadName})
      const squadEntity = await catalog.getEntityByRef(squadRef)
      
      const tribeInSquad = squadEntity?.relations?.find(ref=>{
        return ref?.targetRef.startsWith('group:default/tribe-');
      })

      const tribeEntity = await catalog.getEntityByRef(tribeInSquad?.targetRef || '');

      const verticalInTribe = tribeEntity?.relations?.find(ref=>{
        return ref?.targetRef.startsWith('group:default/vertical-');
      })
      const verticalEntity = await catalog.getEntityByRef(verticalInTribe?.targetRef || '')
      
      // make owners
      const tribeName = tribeEntity?.metadata.name || "undefined"
      const verticalName = verticalEntity?.metadata.name || "undefined" 

      // make project variables
      const packageName = ctx.input.name.trim().replace(" ","").toLowerCase();
      const projectType = ctx.input.type.toLowerCase();
      const artifactId = ctx.input.name.trim().replace(" ","-").toLowerCase()+"-"+projectType;

      //write in output
      ctx.output('squad', squadName)
      ctx.output('tribe', tribeName)
      ctx.output('vertical', verticalName)
      ctx.output('artifactId', artifactId)
      ctx.output('packageName', packageName)
    },
  });
};

2)_scaffolder.js

// Include Action
// path: packages/backend/src/plugins/

import { CatalogClient } from '@backstage/catalog-client';
import { createRouter } from '@backstage/plugin-scaffolder-backend';
import { Router } from 'express';
import type { PluginEnvironment } from '../types';
import { createBuiltinActions } from '@backstage/plugin-scaffolder-backend';
import { ScmIntegrations } from '@backstage/integration';

//Here include your custom action:
import { recoveryVariables } from './scaffolder/actions/template';

export default async function createPlugin(
  env: PluginEnvironment,
): Promise<Router> {
  const catalogClient = new CatalogClient({
    discoveryApi: env.discovery,
  });
  const integrations = ScmIntegrations.fromConfig(env.config);

  // Need add the builtin actions in this case
  const builtInActions = createBuiltinActions({
    integrations: integrations,
    catalogClient: catalogClient,
    config: env.config,
    reader: env.reader,
  });
  
  // add all actions here:
  const actions = [...builtInActions, recoveryVariables(catalogClient)];

  return await createRouter({
    actions: actions,
    logger: env.logger,
    config: env.config,
    database: env.database,
    reader: env.reader,
    catalogClient: catalogClient,
  });
}

3)_template.yaml

  [...]
  
  steps:
    - id: data
      name: Recovery Infos
      action: helpdev:template:variables
      input:
        squad: ${{ parameters.squad }}
        name: ${{ parameters.name }}
        type: ${{ parameters.type }}

    - id: fetchCicdTemplate
      name: Fetch Template
      action: fetch:template
      input:
        url: ./skeleton
        values:
          name: ${{ parameters.name }}
          description: ${{ parameters.description }}
          artifactId: ${{ steps.data.output.artifactId }}
          packageName: ${{ steps.data.output.packageName }}
          squadName: ${{ steps.data.output.squad }}
          tribeName: ${{ steps.data.output.tribe }}
          verticalName: ${{ steps.data.output.vertical }}
          
[...]