Merge pull request #16720 from RobotSail/techdocs

Add Experimental Plugin Support for the Techdocs backend plugin

.changeset/large-feet-wash.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-techdocs-backend': minor
+---
+
+Introduced alpha export of the `techdocsPlugin` using the new backend system.

packages/backend-next/package.json

@@ -29,6 +29,7 @@
     "@backstage/plugin-app-backend": "workspace:^",
     "@backstage/plugin-catalog-backend": "workspace:^",
     "@backstage/plugin-scaffolder-backend": "workspace:^",
+    "@backstage/plugin-techdocs-backend": "workspace:^",
     "@backstage/plugin-todo-backend": "workspace:^"
   },
   "devDependencies": {

packages/backend-next/src/index.ts

@@ -19,6 +19,7 @@ import { catalogModuleTemplateKind } from '@backstage/plugin-scaffolder-backend/
 import { createBackend } from '@backstage/backend-defaults';
 import { appPlugin } from '@backstage/plugin-app-backend/alpha';
 import { todoPlugin } from '@backstage/plugin-todo-backend';
+import { techdocsPlugin } from '@backstage/plugin-techdocs-backend/alpha';
 
 const backend = createBackend();
 
@@ -26,4 +27,5 @@ backend.add(catalogPlugin());
 backend.add(catalogModuleTemplateKind());
 backend.add(appPlugin({ appPackageName: 'example-app' }));
 backend.add(todoPlugin());
+backend.add(techdocsPlugin());
 backend.start();

plugins/techdocs-backend/alpha-api-report.md

@@ -0,0 +1,12 @@
+## API Report File for "@backstage/plugin-techdocs-backend"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import { BackendFeature } from '@backstage/backend-plugin-api';
+
+// @alpha
+export const techdocsPlugin: () => BackendFeature;
+
+// (No @packageDocumentation comment for this package)
+```

plugins/techdocs-backend/package.json

@@ -10,6 +10,21 @@
     "main": "dist/index.cjs.js",
     "types": "dist/index.d.ts"
   },
+  "exports": {
+    ".": "./src/index.ts",
+    "./alpha": "./src/alpha.ts",
+    "./package.json": "./package.json"
+  },
+  "typesVersions": {
+    "*": {
+      "alpha": [
+        "src/alpha.ts"
+      ],
+      "package.json": [
+        "package.json"
+      ]
+    }
+  },
   "backstage": {
     "role": "backend-plugin"
   },
@@ -34,6 +49,7 @@
   },
   "dependencies": {
     "@backstage/backend-common": "workspace:^",
+    "@backstage/backend-plugin-api": "workspace:^",
     "@backstage/catalog-client": "workspace:^",
     "@backstage/catalog-model": "workspace:^",
     "@backstage/config": "workspace:^",

plugins/techdocs-backend/src/alpha.ts

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export { techdocsPlugin } from './plugin';

plugins/techdocs-backend/src/plugin.ts

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  DockerContainerRunner,
+  loggerToWinstonLogger,
+  cacheToPluginCacheManager,
+} from '@backstage/backend-common';
+import {
+  coreServices,
+  createBackendPlugin,
+} from '@backstage/backend-plugin-api';
+
+import {
+  Preparers,
+  Generators,
+  Publisher,
+} from '@backstage/plugin-techdocs-node';
+import Docker from 'dockerode';
+import { createRouter } from '@backstage/plugin-techdocs-backend';
+
+/**
+ * The TechDocs plugin is responsible for serving and building documentation for any entity.
+ * @alpha
+ */
+export const techdocsPlugin = createBackendPlugin({
+  pluginId: 'techdocs',
+  register(env) {
+    env.registerInit({
+      deps: {
+        config: coreServices.config,
+        logger: coreServices.logger,
+        urlReader: coreServices.urlReader,
+        http: coreServices.httpRouter,
+        discovery: coreServices.discovery,
+        cache: coreServices.cache,
+      },
+      async init({ config, logger, urlReader, http, discovery, cache }) {
+        const winstonLogger = loggerToWinstonLogger(logger);
+        // Preparers are responsible for fetching source files for documentation.
+        const preparers = await Preparers.fromConfig(config, {
+          reader: urlReader,
+          logger: winstonLogger,
+        });
+
+        // Docker client (conditionally) used by the generators, based on techdocs.generators config.
+        const dockerClient = new Docker();
+        const containerRunner = new DockerContainerRunner({ dockerClient });
+
+        // Generators are used for generating documentation sites.
+        const generators = await Generators.fromConfig(config, {
+          logger: winstonLogger,
+          containerRunner,
+        });
+
+        // Publisher is used for
+        // 1. Publishing generated files to storage
+        // 2. Fetching files from storage and passing them to TechDocs frontend.
+        const publisher = await Publisher.fromConfig(config, {
+          logger: winstonLogger,
+          discovery: discovery,
+        });
+
+        // checks if the publisher is working and logs the result
+        await publisher.getReadiness();
+
+        const cacheManager = cacheToPluginCacheManager(cache);
+        http.use(
+          await createRouter({
+            logger: winstonLogger,
+            cache: cacheManager,
+            preparers,
+            generators,
+            publisher,
+            config,
+            discovery,
+          }),
+        );
+      },
+    });
+  },
+});

yarn.lock

@@ -8538,6 +8538,7 @@ __metadata:
   resolution: "@backstage/plugin-techdocs-backend@workspace:plugins/techdocs-backend"
   dependencies:
     "@backstage/backend-common": "workspace:^"
+    "@backstage/backend-plugin-api": "workspace:^"
     "@backstage/backend-test-utils": "workspace:^"
     "@backstage/catalog-client": "workspace:^"
     "@backstage/catalog-model": "workspace:^"
@@ -22886,6 +22887,7 @@ __metadata:
     "@backstage/plugin-app-backend": "workspace:^"
     "@backstage/plugin-catalog-backend": "workspace:^"
     "@backstage/plugin-scaffolder-backend": "workspace:^"
+    "@backstage/plugin-techdocs-backend": "workspace:^"
     "@backstage/plugin-todo-backend": "workspace:^"
   languageName: unknown
   linkType: soft