Merge pull request #26684 from MarkForesta/include_dry_run_template_metadata

Include templateMetadata in Dry Run

.changeset/soft-turkeys-tie.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend': patch
+---
+
+Modified `createDryRunner` and corresponding route to include `templateMetaData` inside the `templateInfo`. This allows custom action writers to access things like `templateInfo.entity.metadata.name` via the action context while executing templates using the dry run framework.

plugins/scaffolder-backend/src/scaffolder/dryrun/createDryRunner.ts

@@ -15,10 +15,9 @@
  */
 
 import { ScmIntegrations } from '@backstage/integration';
-import { TaskSpec } from '@backstage/plugin-scaffolder-common';
+import { TaskSpec, TemplateInfo } from '@backstage/plugin-scaffolder-common';
 import { JsonObject } from '@backstage/types';
-import { v4 as uuid } from 'uuid';
-import { pathToFileURL } from 'url';
+import { fileURLToPath } from 'url';
 import { Logger } from 'winston';
 import {
   createTemplateAction,
@@ -29,19 +28,19 @@ import {
   SerializedFile,
   serializeDirectoryContents,
 } from '@backstage/plugin-scaffolder-node';
+import path from 'path';
 import { TemplateActionRegistry } from '../actions';
 import { NunjucksWorkflowRunner } from '../tasks/NunjucksWorkflowRunner';
 import { DecoratedActionsRegistry } from './DecoratedActionsRegistry';
 import fs from 'fs-extra';
 import { PermissionEvaluator } from '@backstage/plugin-permission-common';
-import {
-  BackstageCredentials,
-  resolveSafeChildPath,
-} from '@backstage/backend-plugin-api';
+import { BackstageCredentials } from '@backstage/backend-plugin-api';
 import type { UserEntity } from '@backstage/catalog-model';
+import { v4 as uuid } from 'uuid';
 
 interface DryRunInput {
   spec: TaskSpec;
+  templateInfo: TemplateInfo;
   secrets?: TaskSecrets;
   directoryContents: SerializedFile[];
   credentials: BackstageCredentials;
@@ -94,18 +93,21 @@ export function createDryRunner(options: TemplateTesterCreateOptions) {
       ]),
     });
 
+    // Extracting contentsPath and dryRunId from the baseUrl
+    const baseUrl = input.templateInfo.baseUrl;
+    if (!baseUrl) {
+      throw new Error('baseUrl is required');
+    }
+    const basePath = fileURLToPath(new URL(baseUrl));
+    const contentsPath = path.dirname(basePath);
     const dryRunId = uuid();
+
     const log = new Array<{ body: JsonObject }>();
-    const contentsPath = resolveSafeChildPath(
-      options.workingDirectory,
-      `dry-run-content-${dryRunId}`,
-    );
 
     try {
       await deserializeDirectoryContents(contentsPath, input.directoryContents);
 
       const abortSignal = new AbortController().signal;
-
       const result = await workflowRunner.execute({
         spec: {
           ...input.spec,
@@ -117,12 +119,7 @@ export function createDryRunner(options: TemplateTesterCreateOptions) {
               action: 'dry-run:extract',
             },
           ],
-          templateInfo: {
-            entityRef: 'template:default/dry-run',
-            baseUrl: pathToFileURL(
-              resolveSafeChildPath(contentsPath, 'template.yaml'),
-            ).toString(),
-          },
+          templateInfo: input.templateInfo,
         },
         secrets: input.secrets,
         getInitiatorCredentials: () => Promise.resolve(input.credentials),

plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.test.ts

@@ -1331,6 +1331,39 @@ describe('NunjucksWorkflowRunner', () => {
 
       expect(fakeActionHandler.mock.calls[0][0].isDryRun).toEqual(true);
     });
+
+    it('should have metadata in action context during dry run', async () => {
+      const task = createMockTaskWithSpec(
+        {
+          apiVersion: 'scaffolder.backstage.io/v1beta3',
+          templateInfo: {
+            entityRef: 'dryRun-Entity',
+            entity: { metadata: { name: 'test-template' } },
+          },
+          parameters: {},
+          output: {},
+          steps: [
+            {
+              id: 'test',
+              name: 'name',
+              action: 'jest-validated-action',
+              input: { foo: 1 },
+            },
+          ],
+        },
+        {
+          backstageToken: token,
+        },
+        true,
+      );
+
+      await runner.execute(task);
+
+      expect(fakeActionHandler.mock.calls[0][0].isDryRun).toEqual(true);
+      expect(
+        fakeActionHandler.mock.calls[0][0].templateInfo.entity.metadata.name,
+      ).toEqual('test-template');
+    });
   });
 
   describe('permissions', () => {

plugins/scaffolder-backend/src/service/router.ts

@@ -94,6 +94,7 @@ import {
   PermissionsService,
   SchedulerService,
   UrlReaderService,
+  resolveSafeChildPath,
 } from '@backstage/backend-plugin-api';
 import {
   IdentityApi,
@@ -105,6 +106,8 @@ import {
   AutocompleteHandler,
   WorkspaceProvider,
 } from '@backstage/plugin-scaffolder-node/alpha';
+import { pathToFileURL } from 'url';
+import { v4 as uuid } from 'uuid';
 
 /**
  *
@@ -814,6 +817,22 @@ export async function createRouter(
         name: step.name ?? step.action,
       }));
 
+      const dryRunId = uuid();
+      const contentsPath = resolveSafeChildPath(
+        workingDirectory,
+        `dry-run-content-${dryRunId}`,
+      );
+
+      const templateInfo = {
+        entityRef: stringifyEntityRef(template),
+        entity: {
+          metadata: template.metadata,
+        },
+        baseUrl: pathToFileURL(
+          resolveSafeChildPath(contentsPath, 'template.yaml'),
+        ).toString(),
+      };
+
       const result = await dryRunner({
         spec: {
           apiVersion: template.apiVersion,
@@ -825,6 +844,7 @@ export async function createRouter(
             ref: userEntityRef,
           },
         },
+        templateInfo: templateInfo,
         directoryContents: (body.directoryContents ?? []).map(file => ({
           path: file.path,
           content: Buffer.from(file.base64Content, 'base64'),