Introduce backend-defaults package

Signed-off-by: Johan Haals <johan.haals@gmail.com>

packages/backend-defaults/.eslintrc.js

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+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);

packages/backend-defaults/README.md

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+# @backstage/backend-defaults
+
+**This package is HIGHLY EXPERIMENTAL, do not use this for production**
+
+This package provides the core API used by Backstage backend apps.
+
+## Installation
+
+Add the library to your backend app package:
+
+```bash
+# From your Backstage root directory
+yarn add --cwd packages/backend @backstage/backend-defaults
+```
+
+## Documentation
+
+- [Backstage Readme](https://github.com/backstage/backstage/blob/master/README.md)
+- [Backstage Documentation](https://github.com/backstage/backstage/blob/master/docs/README.md)

packages/backend-defaults/api-report.md

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+## API Report File for "@backstage/backend-defaults"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import { AnyServiceFactory } from '@backstage/backend-plugin-api';
+import { Backend } from '@backstage/backend-app-api';
+
+// @public (undocumented)
+export function createBackend(options?: CreateBackendOptions): Backend;
+
+// @public (undocumented)
+export interface CreateBackendOptions {
+  // (undocumented)
+  serviceFactories?: AnyServiceFactory[];
+}
+
+// (No @packageDocumentation comment for this package)
+```

packages/backend-defaults/package.json

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+{
+  "name": "@backstage/backend-defaults",
+  "description": "Backend defaults used by Backstage backend apps",
+  "version": "0.0.0",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "private": false,
+  "publishConfig": {
+    "access": "public",
+    "main": "dist/index.cjs.js",
+    "types": "dist/index.d.ts",
+    "alphaTypes": "dist/index.alpha.d.ts"
+  },
+  "backstage": {
+    "role": "node-library"
+  },
+  "homepage": "https://backstage.io",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/backstage/backstage",
+    "directory": "packages/backend-defaults"
+  },
+  "keywords": [
+    "backstage"
+  ],
+  "license": "Apache-2.0",
+  "scripts": {
+    "build": "backstage-cli package build --experimental-type-build",
+    "lint": "backstage-cli package lint",
+    "test": "backstage-cli package test",
+    "prepack": "backstage-cli package prepack",
+    "postpack": "backstage-cli package postpack",
+    "clean": "backstage-cli package clean",
+    "start": "backstage-cli package start"
+  },
+  "dependencies": {
+    "@backstage/backend-app-api": "^0.1.1-next.0",
+    "@backstage/backend-plugin-api": "^0.1.1-next.0"
+  },
+  "devDependencies": {
+    "@backstage/cli": "^0.18.1-next.0"
+  },
+  "files": [
+    "dist",
+    "alpha"
+  ]
+}

packages/backend-defaults/src/CreateBackend.ts

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+/*
+ * Copyright 2022 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 {
+  Backend,
+  cacheFactory,
+  configFactory,
+  createSpecializedBackend,
+  databaseFactory,
+  discoveryFactory,
+  httpRouterFactory,
+  loggerFactory,
+  permissionsFactory,
+  schedulerFactory,
+  tokenManagerFactory,
+  urlReaderFactory,
+} from '@backstage/backend-app-api';
+import { CreateBackendOptions } from './types';
+
+export const defaultServiceFactories = [
+  cacheFactory,
+  configFactory,
+  databaseFactory,
+  discoveryFactory,
+  loggerFactory,
+  permissionsFactory,
+  schedulerFactory,
+  tokenManagerFactory,
+  urlReaderFactory,
+  httpRouterFactory,
+];
+
+/**
+ * @public
+ */
+export function createBackend(options?: CreateBackendOptions): Backend {
+  // TODO: merge with provided APIs
+  return createSpecializedBackend({
+    serviceFactories: [
+      ...defaultServiceFactories,
+      ...(options?.serviceFactories || []),
+    ],
+  });
+}

packages/backend-defaults/src/index.ts

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+/*
+ * Copyright 2022 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 type { CreateBackendOptions } from './types';
+export { createBackend } from './CreateBackend';

packages/backend-defaults/src/types.ts

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+/*
+ * Copyright 2022 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 { AnyServiceFactory } from '@backstage/backend-plugin-api';
+
+/**
+ * @public
+ */
+export interface CreateBackendOptions {
+  serviceFactories?: AnyServiceFactory[];
+}