Migrate the optimizer mixin to core (#94272)

* migrate optimizer mixin to core apps

* fix core_app tests

* add integration tests, extract selectCompressedFile

* add CoreApp unit test

* more unit tests

* unit tests for bundle_route

* more unit tests

* remove /src/optimize/ from codeowners

* fix case

* NIT

.github/CODEOWNERS

@@ -145,7 +145,6 @@
 # Operations
 /src/dev/ @elastic/kibana-operations
 /src/setup_node_env/ @elastic/kibana-operations
-/src/optimize/ @elastic/kibana-operations
 /packages/*eslint*/ @elastic/kibana-operations
 /packages/*babel*/ @elastic/kibana-operations
 /packages/kbn-dev-utils*/ @elastic/kibana-operations

src/core/server/core_app/bundle_routes/bundle_route.test.mocks.ts

@@ -0,0 +1,12 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+export const createDynamicAssetHandlerMock = jest.fn();
+jest.doMock('./dynamic_asset_response', () => ({
+  createDynamicAssetHandler: createDynamicAssetHandlerMock,
+}));

src/core/server/core_app/bundle_routes/bundle_route.test.ts

@@ -0,0 +1,70 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { createDynamicAssetHandlerMock } from './bundle_route.test.mocks';
+
+import { httpServiceMock } from '../../http/http_service.mock';
+import { FileHashCache } from './file_hash_cache';
+import { registerRouteForBundle } from './bundles_route';
+
+describe('registerRouteForBundle', () => {
+  let router: ReturnType<typeof httpServiceMock.createRouter>;
+  let fileHashCache: FileHashCache;
+
+  beforeEach(() => {
+    router = httpServiceMock.createRouter();
+    fileHashCache = new FileHashCache();
+  });
+
+  afterEach(() => {
+    createDynamicAssetHandlerMock.mockReset();
+  });
+
+  it('calls `router.get` with the correct parameters', () => {
+    const handler = jest.fn();
+    createDynamicAssetHandlerMock.mockReturnValue(handler);
+
+    registerRouteForBundle(router, {
+      isDist: false,
+      publicPath: '/public-path/',
+      bundlesPath: '/bundle-path',
+      fileHashCache,
+      routePath: '/route-path/',
+    });
+
+    expect(router.get).toHaveBeenCalledTimes(1);
+    expect(router.get).toHaveBeenCalledWith(
+      {
+        path: '/route-path/{path*}',
+        options: {
+          authRequired: false,
+        },
+        validate: expect.any(Object),
+      },
+      handler
+    );
+  });
+
+  it('calls `createDynamicAssetHandler` with the correct parameters', () => {
+    registerRouteForBundle(router, {
+      isDist: false,
+      publicPath: '/public-path/',
+      bundlesPath: '/bundle-path',
+      fileHashCache,
+      routePath: '/route-path/',
+    });
+
+    expect(createDynamicAssetHandlerMock).toHaveBeenCalledTimes(1);
+    expect(createDynamicAssetHandlerMock).toHaveBeenCalledWith({
+      isDist: false,
+      publicPath: '/public-path/',
+      bundlesPath: '/bundle-path',
+      fileHashCache,
+    });
+  });
+});

src/core/server/core_app/bundle_routes/bundles_route.ts

@@ -0,0 +1,49 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+import { IRouter } from '../../http';
+import { createDynamicAssetHandler } from './dynamic_asset_response';
+import { FileHashCache } from './file_hash_cache';
+
+export function registerRouteForBundle(
+  router: IRouter,
+  {
+    publicPath,
+    routePath,
+    bundlesPath,
+    fileHashCache,
+    isDist,
+  }: {
+    publicPath: string;
+    routePath: string;
+    bundlesPath: string;
+    fileHashCache: FileHashCache;
+    isDist: boolean;
+  }
+) {
+  router.get(
+    {
+      path: `${routePath}{path*}`,
+      options: {
+        authRequired: false,
+      },
+      validate: {
+        params: schema.object({
+          path: schema.string(),
+        }),
+      },
+    },
+    createDynamicAssetHandler({
+      publicPath,
+      bundlesPath,
+      isDist,
+      fileHashCache,
+    })
+  );
+}

src/core/server/core_app/bundle_routes/dynamic_asset_response.ts

@@ -0,0 +1,124 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { createReadStream } from 'fs';
+import { resolve, extname } from 'path';
+import mime from 'mime-types';
+import agent from 'elastic-apm-node';
+
+import { fstat, close } from './fs';
+import { RequestHandler } from '../../http';
+import { IFileHashCache } from './file_hash_cache';
+import { getFileHash } from './file_hash';
+import { selectCompressedFile } from './select_compressed_file';
+
+const MINUTE = 60;
+const HOUR = 60 * MINUTE;
+const DAY = 24 * HOUR;
+
+/**
+ *  Serve asset for the requested path. This is designed
+ *  to replicate a subset of the features provided by Hapi's Inert
+ *  plugin including:
+ *   - ensure path is not traversing out of the bundle directory
+ *   - manage use file descriptors for file access to efficiently
+ *     interact with the file multiple times in each request
+ *   - generate and cache etag for the file
+ *   - write correct headers to response for client-side caching
+ *     and invalidation
+ *   - stream file to response
+ *
+ *  It differs from Inert in some important ways:
+ *   - cached hash/etag is based on the file on disk, but modified
+ *     by the public path so that individual public paths have
+ *     different etags, but can share a cache
+ */
+export const createDynamicAssetHandler = ({
+  bundlesPath,
+  fileHashCache,
+  isDist,
+  publicPath,
+}: {
+  bundlesPath: string;
+  publicPath: string;
+  fileHashCache: IFileHashCache;
+  isDist: boolean;
+}): RequestHandler<{ path: string }, {}, {}> => {
+  return async (ctx, req, res) => {
+    agent.setTransactionName('GET ?/bundles/?');
+
+    let fd: number | undefined;
+    let fileEncoding: 'gzip' | 'br' | undefined;
+
+    try {
+      const path = resolve(bundlesPath, req.params.path);
+
+      // prevent path traversal, only process paths that resolve within bundlesPath
+      if (!path.startsWith(bundlesPath)) {
+        return res.forbidden({
+          body: 'EACCES',
+        });
+      }
+
+      // we use and manage a file descriptor mostly because
+      // that's what Inert does, and since we are accessing
+      // the file 2 or 3 times per request it seems logical
+      ({ fd, fileEncoding } = await selectCompressedFile(
+        req.headers['accept-encoding'] as string,
+        path
+      ));
+
+      let headers: Record<string, string>;
+      if (isDist) {
+        headers = { 'cache-control': `max-age=${365 * DAY}` };
+      } else {
+        const stat = await fstat(fd);
+        const hash = await getFileHash(fileHashCache, path, stat, fd);
+        headers = {
+          etag: `${hash}-${publicPath}`,
+          'cache-control': 'must-revalidate',
+        };
+      }
+
+      // If we manually selected a compressed file, specify the encoding header.
+      // Otherwise, let Hapi automatically gzip the response.
+      if (fileEncoding) {
+        headers['content-encoding'] = fileEncoding;
+      }
+
+      const fileExt = extname(path);
+      const contentType = mime.lookup(fileExt);
+      const mediaType = mime.contentType(contentType || fileExt);
+      headers['content-type'] = mediaType || '';
+
+      const content = createReadStream(null as any, {
+        fd,
+        start: 0,
+        autoClose: true,
+      });
+
+      return res.ok({
+        body: content,
+        headers,
+      });
+    } catch (error) {
+      if (fd) {
+        try {
+          await close(fd);
+        } catch (_) {
+          // ignore errors from close, we already have one to report
+          // and it's very likely they are the same
+        }
+      }
+      if (error.code === 'ENOENT') {
+        return res.notFound();
+      }
+      throw error;
+    }
+  };
+};

src/core/server/core_app/bundle_routes/file_hash.test.mocks.ts

@@ -0,0 +1,15 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+export const generateFileHashMock = jest.fn();
+export const getFileCacheKeyMock = jest.fn();
+
+jest.doMock('./utils', () => ({
+  generateFileHash: generateFileHashMock,
+  getFileCacheKey: getFileCacheKeyMock,
+}));

src/core/server/core_app/bundle_routes/file_hash.test.ts

@@ -0,0 +1,72 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { generateFileHashMock, getFileCacheKeyMock } from './file_hash.test.mocks';
+
+import { resolve } from 'path';
+import { Stats } from 'fs';
+import { getFileHash } from './file_hash';
+import { IFileHashCache } from './file_hash_cache';
+
+const mockedCache = (): jest.Mocked<IFileHashCache> => ({
+  del: jest.fn(),
+  get: jest.fn(),
+  set: jest.fn(),
+});
+
+describe('getFileHash', () => {
+  const sampleFilePath = resolve(__dirname, 'foo.js');
+  const fd = 42;
+  const stats: Stats = { ino: 42, size: 9000 } as any;
+
+  beforeEach(() => {
+    getFileCacheKeyMock.mockImplementation((path: string, stat: Stats) => `${path}-${stat.ino}`);
+  });
+
+  afterEach(() => {
+    generateFileHashMock.mockReset();
+    getFileCacheKeyMock.mockReset();
+  });
+
+  it('returns the value from cache if present', async () => {
+    const cache = mockedCache();
+    cache.get.mockReturnValue(Promise.resolve('cached-hash'));
+
+    const hash = await getFileHash(cache, sampleFilePath, stats, fd);
+
+    expect(cache.get).toHaveBeenCalledTimes(1);
+    expect(generateFileHashMock).not.toHaveBeenCalled();
+    expect(hash).toEqual('cached-hash');
+  });
+
+  it('computes the value if not present in cache', async () => {
+    const cache = mockedCache();
+    cache.get.mockReturnValue(undefined);
+
+    generateFileHashMock.mockReturnValue(Promise.resolve('computed-hash'));
+
+    const hash = await getFileHash(cache, sampleFilePath, stats, fd);
+
+    expect(generateFileHashMock).toHaveBeenCalledTimes(1);
+    expect(generateFileHashMock).toHaveBeenCalledWith(fd);
+    expect(hash).toEqual('computed-hash');
+  });
+
+  it('sets the value in the cache if not present', async () => {
+    const computedHashPromise = Promise.resolve('computed-hash');
+    generateFileHashMock.mockReturnValue(computedHashPromise);
+
+    const cache = mockedCache();
+    cache.get.mockReturnValue(undefined);
+
+    await getFileHash(cache, sampleFilePath, stats, fd);
+
+    expect(cache.set).toHaveBeenCalledTimes(1);
+    expect(cache.set).toHaveBeenCalledWith(`${sampleFilePath}-${stats.ino}`, computedHashPromise);
+  });
+});

src/core/server/core_app/bundle_routes/file_hash.ts

@@ -0,0 +1,32 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import type { Stats } from 'fs';
+import { generateFileHash, getFileCacheKey } from './utils';
+import { IFileHashCache } from './file_hash_cache';
+
+/**
+ *  Get the hash of a file via a file descriptor
+ */
+export async function getFileHash(cache: IFileHashCache, path: string, stat: Stats, fd: number) {
+  const key = getFileCacheKey(path, stat);
+
+  const cached = cache.get(key);
+  if (cached) {
+    return await cached;
+  }
+
+  const promise = generateFileHash(fd).catch((error) => {
+    // don't cache failed attempts
+    cache.del(key);
+    throw error;
+  });
+
+  cache.set(key, promise);
+  return await promise;
+}