Experimental: Serverless Trace target

package.json

@@ -81,6 +81,7 @@
     "execa": "2.0.3",
     "express": "4.17.0",
     "faunadb": "2.6.1",
+    "firebase": "6.3.4",
     "fs-extra": "7.0.1",
     "get-port": "5.0.0",
     "isomorphic-unfetch": "3.0.0",

packages/next-server/server/config.ts

@@ -1,9 +1,10 @@
-import os from 'os'
 import findUp from 'find-up'
+import os from 'os'
+
 import { CONFIG_FILE } from '../lib/constants'
 import { execOnce } from '../lib/utils'
 
-const targets = ['server', 'serverless']
+const targets = ['server', 'serverless', 'experimental-serverless-trace']
 
 const defaultConfig: { [key: string]: any } = {
   env: [],
@@ -120,10 +121,12 @@ export default function loadConfig(
     }
 
     if (
-      userConfig.target === 'serverless' &&
+      userConfig.target &&
+      userConfig.target !== 'server' &&
       userConfig.publicRuntimeConfig &&
       Object.keys(userConfig.publicRuntimeConfig).length !== 0
     ) {
+      // TODO: change error message tone to "Only compatible with [fat] server mode"
       throw new Error(
         'Cannot use publicRuntimeConfig with target=serverless https://err.sh/zeit/next.js/serverless-publicRuntimeConfig'
       )
@@ -134,3 +137,9 @@ export default function loadConfig(
 
   return defaultConfig
 }
+
+export function isTargetLikeServerless(target: string) {
+  const isServerless = target === 'serverless'
+  const isServerlessTrace = target === 'experimental-serverless-trace'
+  return isServerless || isServerlessTrace
+}

packages/next-server/server/next-server.ts

@@ -1,13 +1,12 @@
+import compression from 'compression'
 import fs from 'fs'
 import { IncomingMessage, ServerResponse } from 'http'
 import { join, resolve, sep } from 'path'
 import { parse as parseQs, ParsedUrlQuery } from 'querystring'
 import { parse as parseUrl, UrlWithParsedQuery } from 'url'
-import compression from 'compression'
 
 import {
   BUILD_ID_FILE,
-  BUILD_MANIFEST,
   CLIENT_PUBLIC_FILES_PATH,
   CLIENT_STATIC_FILES_PATH,
   CLIENT_STATIC_FILES_RUNTIME,
@@ -25,12 +24,12 @@ import {
 import * as envConfig from '../lib/runtime-config'
 import { NextApiRequest, NextApiResponse } from '../lib/utils'
 import { apiResolver } from './api-utils'
-import loadConfig from './config'
+import loadConfig, { isTargetLikeServerless } from './config'
 import { recursiveReadDirSync } from './lib/recursive-readdir-sync'
 import { loadComponents, LoadComponentsReturnType } from './load-components'
 import { renderToHTML } from './render'
 import { getPagePath } from './require'
-import Router, { route, Route, RouteMatch, Params } from './router'
+import Router, { Params, route, Route, RouteMatch } from './router'
 import { sendHTML } from './send-html'
 import { serveStatic } from './serve-static'
 import { isBlockedPage, isInternalUrl } from './utils'
@@ -98,7 +97,9 @@ export default class Server {
     this.publicDir = join(this.dir, CLIENT_PUBLIC_FILES_PATH)
     this.pagesManifest = join(
       this.distDir,
-      this.nextConfig.target || 'server',
+      this.nextConfig.target === 'server'
+        ? SERVER_DIRECTORY
+        : SERVERLESS_DIRECTORY,
       PAGES_MANIFEST
     )
 
@@ -131,7 +132,7 @@ export default class Server {
       this.renderOpts.runtimeConfig = publicRuntimeConfig
     }
 
-    if (compress && this.nextConfig.target !== 'serverless') {
+    if (compress && this.nextConfig.target === 'server') {
       this.compression = compression() as Middleware
     }
 
@@ -319,7 +320,7 @@ export default class Server {
       return this.render404(req, res)
     }
 
-    if (!this.renderOpts.dev && this.nextConfig.target === 'serverless') {
+    if (!this.renderOpts.dev && this._isLikeServerless) {
       const mod = require(resolverFunction)
       if (typeof mod.default === 'function') {
         return mod.default(req, res)
@@ -342,7 +343,7 @@ export default class Server {
     return getPagePath(
       pathname,
       this.distDir,
-      this.nextConfig.target === 'serverless',
+      this._isLikeServerless,
       this.renderOpts.dev
     )
   }
@@ -352,9 +353,7 @@ export default class Server {
     const publicFiles = recursiveReadDirSync(this.publicDir)
     const serverBuildPath = join(
       this.distDir,
-      this.nextConfig.target === 'serverless'
-        ? SERVERLESS_DIRECTORY
-        : SERVER_DIRECTORY
+      this._isLikeServerless ? SERVERLESS_DIRECTORY : SERVER_DIRECTORY
     )
     const pagesManifest = require(join(serverBuildPath, PAGES_MANIFEST))
 
@@ -458,8 +457,7 @@ export default class Server {
     pathname: string,
     query: ParsedUrlQuery = {}
   ) {
-    const serverless =
-      !this.renderOpts.dev && this.nextConfig.target === 'serverless'
+    const serverless = !this.renderOpts.dev && this._isLikeServerless
     // try serving a static AMP version first
     if (query.amp) {
       try {
@@ -708,4 +706,8 @@ export default class Server {
       throw err
     }
   }
+
+  private get _isLikeServerless(): boolean {
+    return isTargetLikeServerless(this.nextConfig.target)
+  }
 }

packages/next/build/entries.ts

@@ -1,6 +1,8 @@
+import { isTargetLikeServerless } from 'next-server/dist/server/config'
 import { join } from 'path'
 import { stringify } from 'querystring'
-import { PAGES_DIR_ALIAS, DOT_NEXT_ALIAS, API_ROUTE } from '../lib/constants'
+
+import { API_ROUTE, DOT_NEXT_ALIAS, PAGES_DIR_ALIAS } from '../lib/constants'
 import { ServerlessLoaderQuery } from './webpack/loaders/next-serverless-loader'
 
 type PagesMapping = {
@@ -45,7 +47,7 @@ type Entrypoints = {
 
 export function createEntrypoints(
   pages: PagesMapping,
-  target: 'server' | 'serverless',
+  target: 'server' | 'serverless' | 'experimental-serverless-trace',
   buildId: string,
   dynamicBuildId: boolean,
   config: any
@@ -72,7 +74,9 @@ export function createEntrypoints(
 
     const bundlePath = join('static', buildId, 'pages', bundleFile)
 
-    if (isApiRoute && target === 'serverless') {
+    const isLikeServerless = isTargetLikeServerless(target)
+
+    if (isApiRoute && isLikeServerless) {
       const serverlessLoaderOptions: ServerlessLoaderQuery = {
         page,
         absolutePagePath,
@@ -83,11 +87,7 @@ export function createEntrypoints(
       )}!`
     } else if (isApiRoute || target === 'server') {
       server[bundlePath] = [absolutePagePath]
-    } else if (
-      target === 'serverless' &&
-      page !== '/_app' &&
-      page !== '/_document'
-    ) {
+    } else if (isLikeServerless && page !== '/_app' && page !== '/_document') {
       const serverlessLoaderOptions: ServerlessLoaderQuery = {
         page,
         absolutePagePath,

packages/next/build/index.ts

@@ -1,18 +1,25 @@
+import { Sema } from 'async-sema'
 import chalk from 'chalk'
+import fs from 'fs'
+import mkdirpOrig from 'mkdirp'
 import {
-  SERVER_DIRECTORY,
-  SERVERLESS_DIRECTORY,
-  PAGES_MANIFEST,
   CHUNK_GRAPH_MANIFEST,
+  PAGES_MANIFEST,
   PHASE_PRODUCTION_BUILD,
+  SERVER_DIRECTORY,
+  SERVERLESS_DIRECTORY,
 } from 'next-server/constants'
-import loadConfig from 'next-server/next-config'
+import loadConfig, {
+  isTargetLikeServerless,
+} from 'next-server/dist/server/config'
 import nanoid from 'next/dist/compiled/nanoid/index.js'
 import path from 'path'
-import fs from 'fs'
 import { promisify } from 'util'
+import workerFarm from 'worker-farm'
+
 import formatWebpackMessages from '../client/dev/error-overlay/format-webpack-messages'
 import { recursiveDelete } from '../lib/recursive-delete'
+import { recursiveReadDir } from '../lib/recursive-readdir'
 import { verifyTypeScriptSetup } from '../lib/verifyTypeScriptSetup'
 import { CompilerResult, runCompiler } from './compiler'
 import { createEntrypoints, createPagesMapping } from './entries'
@@ -25,20 +32,16 @@ import {
   getFileForPage,
   getPageSizeInKb,
   getSpecifiedPages,
-  printTreeView,
-  PageInfo,
   hasCustomAppGetInitialProps,
+  PageInfo,
+  printTreeView,
 } from './utils'
 import getBaseWebpackConfig from './webpack-config'
 import {
   exportManifest,
   getPageChunks,
 } from './webpack/plugins/chunk-graph-plugin'
 import { writeBuildId } from './write-build-id'
-import { recursiveReadDir } from '../lib/recursive-readdir'
-import mkdirpOrig from 'mkdirp'
-import workerFarm from 'worker-farm'
-import { Sema } from 'async-sema'
 
 const fsUnlink = promisify(fs.unlink)
 const fsRmdir = promisify(fs.rmdir)
@@ -75,11 +78,13 @@ export default async function build(dir: string, conf = null): Promise<void> {
     isFlyingShuttle || process.env.__NEXT_BUILDER_EXPERIMENTAL_PAGE
   )
 
+  const isLikeServerless = isTargetLikeServerless(target)
+
   if (selectivePageBuilding && target !== 'serverless') {
     throw new Error(
       `Cannot use ${
         isFlyingShuttle ? 'flying shuttle' : '`now dev`'
-      } without the serverless target.`
+      } without the \`serverless\` target.`
     )
   }
 
@@ -199,7 +204,8 @@ export default async function build(dir: string, conf = null): Promise<void> {
   ])
 
   let result: CompilerResult = { warnings: [], errors: [] }
-  if (target === 'serverless') {
+  // TODO: why do we need this??
+  if (isLikeServerless) {
     const clientResult = await runCompiler(configs[0])
     // Fail build if clientResult contains errors
     if (clientResult.errors.length > 0) {
@@ -273,7 +279,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
   const pageKeys = Object.keys(mappedPages)
   const manifestPath = path.join(
     distDir,
-    target === 'serverless' ? SERVERLESS_DIRECTORY : SERVER_DIRECTORY,
+    isLikeServerless ? SERVERLESS_DIRECTORY : SERVER_DIRECTORY,
     PAGES_MANIFEST
   )
 
@@ -303,12 +309,12 @@ export default async function build(dir: string, conf = null): Promise<void> {
       const actualPage = page === '/' ? '/index' : page
       const size = await getPageSizeInKb(actualPage, distPath, buildId)
       const bundleRelative = path.join(
-        target === 'serverless' ? 'pages' : `static/${buildId}/pages`,
+        isLikeServerless ? 'pages' : `static/${buildId}/pages`,
         actualPage + '.js'
       )
       const serverBundle = path.join(
         distPath,
-        target === 'serverless' ? SERVERLESS_DIRECTORY : SERVER_DIRECTORY,
+        isLikeServerless ? SERVERLESS_DIRECTORY : SERVER_DIRECTORY,
         bundleRelative
       )
 
@@ -324,7 +330,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
 
       if (nonReservedPage && customAppGetInitialProps === undefined) {
         customAppGetInitialProps = hasCustomAppGetInitialProps(
-          target === 'serverless'
+          isLikeServerless
             ? serverBundle
             : path.join(
                 distPath,
@@ -437,7 +443,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
     for (const file of toMove) {
       const orig = path.join(exportOptions.outdir, file)
       const dest = path.join(serverDir, file)
-      const relativeDest = (target === 'serverless'
+      const relativeDest = (isLikeServerless
         ? path.join('pages', file)
         : path.join('static', buildId, 'pages', file)
       ).replace(/\\/g, '/')
@@ -465,9 +471,5 @@ export default async function build(dir: string, conf = null): Promise<void> {
     await flyingShuttle.save(allStaticPages, pageInfos)
   }
 
-  printTreeView(
-    Object.keys(allMappedPages),
-    allPageInfos,
-    target === 'serverless'
-  )
+  printTreeView(Object.keys(allMappedPages), allPageInfos, isLikeServerless)
 }

packages/next/build/webpack-config.ts

@@ -1,10 +1,10 @@
 import ForkTsCheckerWebpackPlugin from 'fork-ts-checker-webpack-plugin'
-import fs from 'fs'
 import {
   CLIENT_STATIC_FILES_RUNTIME_MAIN,
   CLIENT_STATIC_FILES_RUNTIME_WEBPACK,
   REACT_LOADABLE_MANIFEST,
   SERVER_DIRECTORY,
+  SERVERLESS_DIRECTORY,
 } from 'next-server/constants'
 import resolve from 'next/dist/compiled/resolve/index.js'
 import path from 'path'
@@ -25,14 +25,14 @@ import ChunkNamesPlugin from './webpack/plugins/chunk-names-plugin'
 import { importAutoDllPlugin } from './webpack/plugins/dll-import'
 import { HashedChunkIdsPlugin } from './webpack/plugins/hashed-chunk-ids-plugin'
 import { DropClientPage } from './webpack/plugins/next-drop-client-page-plugin'
+import NextEsmPlugin from './webpack/plugins/next-esm-plugin'
 import NextJsSsrImportPlugin from './webpack/plugins/nextjs-ssr-import'
 import NextJsSSRModuleCachePlugin from './webpack/plugins/nextjs-ssr-module-cache'
 import PagesManifestPlugin from './webpack/plugins/pages-manifest-plugin'
 import { ReactLoadablePlugin } from './webpack/plugins/react-loadable-plugin'
 import { ServerlessPlugin } from './webpack/plugins/serverless-plugin'
 import { SharedRuntimePlugin } from './webpack/plugins/shared-runtime-plugin'
 import { TerserPlugin } from './webpack/plugins/terser-webpack-plugin/src/index'
-import NextEsmPlugin from './webpack/plugins/next-esm-plugin'
 
 type ExcludesFalse = <T>(x: T | false) => x is T
 
@@ -79,7 +79,12 @@ export default async function getBaseWebpackConfig(
     .split(process.platform === 'win32' ? ';' : ':')
     .filter(p => !!p)
 
-  const outputDir = target === 'serverless' ? 'serverless' : SERVER_DIRECTORY
+  const isServerless = target === 'serverless'
+  const isServerlessTrace = target === 'experimental-serverless-trace'
+  // Intentionally not using isTargetLikeServerless helper
+  const isLikeServerless = isServerless || isServerlessTrace
+
+  const outputDir = isLikeServerless ? SERVERLESS_DIRECTORY : SERVER_DIRECTORY
   const outputPath = path.join(distDir, isServer ? outputDir : '')
   const totalPages = Object.keys(entrypoints).length
   const clientEntries = !isServer
@@ -238,7 +243,7 @@ export default async function getBaseWebpackConfig(
     target: isServer ? 'node' : 'web',
     externals: !isServer
       ? undefined
-      : target !== 'serverless'
+      : !isServerless
       ? [
           (context, request, callback) => {
             const notExternalModules = [
@@ -293,8 +298,8 @@ export default async function getBaseWebpackConfig(
           },
         ]
       : [
-          // When the serverless target is used all node_modules will be compiled into the output bundles
-          // So that the serverless bundles have 0 runtime dependencies
+          // When the 'serverless' target is used all node_modules will be compiled into the output bundles
+          // So that the 'serverless' bundles have 0 runtime dependencies
           'amp-toolbox-optimizer', // except this one
           (context, request, callback) => {
             if (
@@ -561,11 +566,14 @@ export default async function getBaseWebpackConfig(
             )
           },
         }),
-      target === 'serverless' &&
-        (isServer || selectivePageBuilding) &&
-        new ServerlessPlugin(buildId, { isServer }),
-      isServer && new PagesManifestPlugin(target === 'serverless'),
-      target !== 'serverless' &&
+      isLikeServerless &&
+        new ServerlessPlugin(buildId, {
+          isServer,
+          isFlyingShuttle: selectivePageBuilding,
+          isTrace: isServerlessTrace,
+        }),
+      isServer && new PagesManifestPlugin(isLikeServerless),
+      target === 'server' &&
         isServer &&
         new NextJsSSRModuleCachePlugin({ outputPath }),
       isServer && new NextJsSsrImportPlugin(),