feat(scaffolder): add new plugin for extending scaffolder actions (#67)

README.md

@@ -16,6 +16,8 @@ This SeatGeek Backstage Plugins Collection offers the following plugins:
   - [plugins/aws-catalog-backend](plugins/aws-catalog-backend)
 - **Gitlab Catalog**: the Gitlab Catalog Plugin offers catalog integrations with the Gitlab API.
   - [plugins/gitlab-catalog-backend](plugins/gitlab-catalog-backend/)
+- **HCL Scaffolder Actions**: the HCL Scaffolder Actions plugin includes custom actions for working with HCL in your Backstage Software Templates.
+  - [plugins/scaffolder-backend-module-hcl](plugins/scaffolder-backend-module-hcl/)
 
 Each of the plugins contain instructions for installation and development within
 their respective locations.

plugins/scaffolder-backend-module-hcl/.eslintrc.js

@@ -0,0 +1,5 @@
+/*
+ * Copyright SeatGeek
+ * Licensed under the terms of the Apache-2.0 license. See LICENSE file in project root for terms.
+ */
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);

plugins/scaffolder-backend-module-hcl/.gitignore

@@ -0,0 +1 @@
+testdir/

plugins/scaffolder-backend-module-hcl/README.md

@@ -0,0 +1,30 @@
+# scaffolder-backend-module-hcl
+
+This contains a collection of actions to use in scaffolder templates for working with HCL (Hashicorp Configuration Language). See https://github.com/hashicorp/hcl to learn more about HCL.
+
+## Getting started
+
+### From your Backstage root directory
+
+```bash
+# From your Backstage root directory
+yarn add --cwd packages/backend @seatgeek/backstage-plugin-scaffolder-backend-module-hcl
+```
+
+Then ensure that both the scaffolder and this module are added to your backend:
+
+```typescript
+// In packages/backend/src/index.ts
+const backend = createBackend();
+// ...
+backend.add(import('@seatgeek/backstage-plugin-scaffolder-backend-module-hcl'));
+```
+
+After that you can use the actions in your template.
+
+## Actions
+
+- `hcl:merge` Merge HCL strings
+- `hcl:merge:write` Merge HCL strings and write to a file
+- `hcl:merge:files` Merge HCL files
+- `hcl:merge:files:write` Merge HCL files and write to a file

plugins/scaffolder-backend-module-hcl/package.json

@@ -0,0 +1,48 @@
+{
+  "name": "@seatgeek/backstage-plugin-scaffolder-backend-module-hcl",
+  "version": "0.0.0-semantically-released",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "license": "Apache-2.0",
+  "publishConfig": {
+    "access": "public",
+    "main": "dist/index.cjs.js",
+    "types": "dist/index.d.ts"
+  },
+  "backstage": {
+    "role": "backend-plugin-module",
+    "pluginId": "scaffolder",
+    "pluginPackages": [
+      "@seatgeek/backstage-plugin-scaffolder-backend-module-hcl"
+    ],
+    "pluginPackage": "@backstage/plugin-scaffolder-backend"
+  },
+  "scripts": {
+    "start": "backstage-cli package start",
+    "build": "backstage-cli package build",
+    "lint": "backstage-cli package lint",
+    "test": "backstage-cli package test --no-cache",
+    "clean": "backstage-cli package clean",
+    "prepack": "backstage-cli package prepack",
+    "postpack": "backstage-cli package postpack"
+  },
+  "dependencies": {
+    "@backstage/backend-common": "^0.24.1",
+    "@backstage/backend-plugin-api": "^0.8.1",
+    "@backstage/config": "^1.2.0",
+    "@backstage/plugin-scaffolder-node": "^0.4.10",
+    "@seatgeek/node-hcl": "^1.0.0",
+    "fs-extra": "^11.2.0",
+    "zod": "^3.23.8"
+  },
+  "devDependencies": {
+    "@backstage/cli": "^0.27.0",
+    "@testing-library/jest-dom": "^5.10.1",
+    "@types/fs-extra": "^11.0.4",
+    "msw": "^1.0.0",
+    "stream": "^0.0.3"
+  },
+  "files": [
+    "dist"
+  ]
+}

plugins/scaffolder-backend-module-hcl/src/actions/hcl/hcl.test.ts

@@ -0,0 +1,119 @@
+/*
+ * Copyright SeatGeek
+ * Licensed under the terms of the Apache-2.0 license. See LICENSE file in project root for terms.
+ */
+import { getVoidLogger } from '@backstage/backend-common';
+import { randomBytes } from 'crypto';
+import { writeFileSync } from 'fs-extra';
+import { tmpdir } from 'os';
+import { PassThrough } from 'stream';
+import { createHclMergeAction, createHclMergeFilesAction } from './hcl';
+
+// Since we have to
+const TMP_DIR = tmpdir();
+
+describe('createHclMergeAction', () => {
+  const mockContext = {
+    logger: getVoidLogger(),
+    logStream: new PassThrough(),
+    output: jest.fn(),
+    createTemporaryDirectory: jest.fn(),
+    checkpoint: jest.fn(),
+    getInitiatorCredentials: jest.fn(),
+    workspacePath: '.',
+  };
+
+  it('should merge HCL files', async () => {
+    const a = `
+    variable "name" {
+      description = "Name to be used on all the resources as identifier"
+      type        = string
+      default     = ""
+    }`;
+
+    const b = `
+    variable "name" {
+      type        = string
+      default     = "my-name"
+    }`;
+
+    const expected = `variable "name" {
+  default     = "my-name"
+  description = "Name to be used on all the resources as identifier"
+  type        = string
+}
+
+`;
+
+    const mockCtx = {
+      ...mockContext,
+      input: {
+        aSourceContent: a,
+        bSourceContent: b,
+      },
+    };
+
+    await createHclMergeAction().handler(mockCtx);
+
+    expect(mockCtx.output.mock.calls[0][0]).toEqual('hcl');
+    expect(mockCtx.output.mock.calls[0][1]).toEqual(expected);
+  });
+});
+
+describe('createHclMergeFilesAction', () => {
+  const mockContext = {
+    logger: getVoidLogger(),
+    logStream: new PassThrough(),
+    output: jest.fn(),
+    createTemporaryDirectory: jest.fn(),
+    checkpoint: jest.fn(),
+    getInitiatorCredentials: jest.fn(),
+    workspacePath: TMP_DIR,
+  };
+
+  it('should merge HCL files', async () => {
+    const a = `
+    variable "name" {
+      description = "Name to be used on all the resources as identifier"
+      type        = string
+      default     = ""
+    }`;
+
+    const b = `
+    variable "name" {
+      type        = string
+      default     = "my-name"
+    }`;
+
+    const expected = `variable "name" {
+  default     = "my-name"
+  description = "Name to be used on all the resources as identifier"
+  type        = string
+}
+
+`;
+
+    const aPath = `${mockContext.workspacePath}/${randomBytes(12).toString(
+      'hex',
+    )}.hcl`;
+    await writeFileSync(aPath, a, 'utf8');
+
+    const bPath = `${mockContext.workspacePath}/${randomBytes(12).toString(
+      'hex',
+    )}.hcl`;
+    await writeFileSync(bPath, b, 'utf8');
+
+    const mockCtx = {
+      ...mockContext,
+      input: {
+        aSourcePath: aPath,
+        bSourcePath: bPath,
+      },
+    };
+
+    await createHclMergeFilesAction().handler(mockCtx);
+
+    expect(mockCtx.output.mock.calls[0][0]).toEqual('hcl');
+    expect(mockCtx.output.mock.calls[0][1]).toEqual(expected);
+  });
+});