feat: node middleware (#725)

* initial implementation

* fix linting

* hack for deployed lambda

* use standalone for middleware trace

* support for external middleware

* fix test and linting

* fix top level await in the middleware

* fix comment

* changeset

* add function manifest to edge plugins

* fix matcher when function manifest exist but no node middleware
remove useless function

* fix in case it can't find function manifest

* remove comment

* review fix

* Apply suggestions from code review

Co-authored-by: Victor Berchet <[email protected]>

* review fix

---------

Co-authored-by: Victor Berchet <[email protected]>

Author: conico974

.changeset/nasty-geckos-sniff.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": minor
+---
+
+Add support for the node middleware

packages/open-next/src/adapters/config/index.ts

@@ -8,6 +8,7 @@ import {
   loadBuildId,
   loadConfig,
   loadConfigHeaders,
+  loadFunctionsConfigManifest,
   loadHtmlPages,
   loadMiddlewareManifest,
   loadPrerenderManifest,
@@ -35,3 +36,6 @@ export const MiddlewareManifest =
 export const AppPathsManifest = /* @__PURE__ */ loadAppPathsManifest(NEXT_DIR);
 export const AppPathRoutesManifest =
   /* @__PURE__ */ loadAppPathRoutesManifest(NEXT_DIR);
+
+export const FunctionsConfigManifest =
+  /* @__PURE__ */ loadFunctionsConfigManifest(NEXT_DIR);

packages/open-next/src/adapters/config/util.ts

@@ -1,6 +1,7 @@
 import fs from "node:fs";
 import path from "node:path";
 import type {
+  FunctionsConfigManifest,
   MiddlewareManifest,
   NextConfig,
   PrerenderManifest,
@@ -123,3 +124,13 @@ export function loadMiddlewareManifest(nextDir: string) {
   const json = fs.readFileSync(filePath, "utf-8");
   return JSON.parse(json) as MiddlewareManifest;
 }
+
+export function loadFunctionsConfigManifest(nextDir: string) {
+  const filePath = path.join(nextDir, "server/functions-config-manifest.json");
+  try {
+    const json = fs.readFileSync(filePath, "utf-8");
+    return JSON.parse(json) as FunctionsConfigManifest;
+  } catch (e) {
+    return { functions: {}, version: 1 };
+  }
+}

packages/open-next/src/build/compileConfig.ts

@@ -50,7 +50,7 @@ export async function compileOpenNextConfig(
   // We need to check if the config uses the edge runtime at any point
   // If it does, we need to compile it with the edge runtime
   const usesEdgeRuntime =
-    config.middleware?.external ||
+    (config.middleware?.external && config.middleware.runtime !== "node") ||
     Object.values(config.functions || {}).some((fn) => fn.runtime === "edge");
   if (!usesEdgeRuntime) {
     logger.debug(

packages/open-next/src/build/constant.ts

@@ -0,0 +1,2 @@
+//TODO: Move all other manifest path here as well
+export const MIDDLEWARE_TRACE_FILE = "server/middleware.js.nft.json";

packages/open-next/src/build/copyTracedFiles.ts

@@ -15,6 +15,7 @@ import path from "node:path";
 import type { NextConfig, PrerenderManifest } from "types/next-types";
 
 import logger from "../logger.js";
+import { MIDDLEWARE_TRACE_FILE } from "./constant.js";
 
 const __dirname = url.fileURLToPath(new URL(".", import.meta.url));
 
@@ -24,14 +25,24 @@ function copyPatchFile(outputDir: string) {
   copyFileSync(patchFile, outputPatchFile);
 }
 
+interface CopyTracedFilesOptions {
+  buildOutputPath: string;
+  packagePath: string;
+  outputDir: string;
+  routes: string[];
+  bundledNextServer: boolean;
+  skipServerFiles?: boolean;
+}
+
 // eslint-disable-next-line sonarjs/cognitive-complexity
-export async function copyTracedFiles(
-  buildOutputPath: string,
-  packagePath: string,
-  outputDir: string,
-  routes: string[],
-  bundledNextServer: boolean,
-) {
+export async function copyTracedFiles({
+  buildOutputPath,
+  packagePath,
+  outputDir,
+  routes,
+  bundledNextServer,
+  skipServerFiles,
+}: CopyTracedFilesOptions) {
   const tsStart = Date.now();
   const dotNextDir = path.join(buildOutputPath, ".next");
   const standaloneDir = path.join(dotNextDir, "standalone");
@@ -58,10 +69,11 @@ export async function copyTracedFiles(
   const filesToCopy = new Map<string, string>();
 
   // Files necessary by the server
-  extractFiles(requiredServerFiles.files).forEach((f) => {
-    filesToCopy.set(f, f.replace(standaloneDir, outputDir));
-  });
-
+  if (!skipServerFiles) {
+    extractFiles(requiredServerFiles.files).forEach((f) => {
+      filesToCopy.set(f, f.replace(standaloneDir, outputDir));
+    });
+  }
   // create directory for pages
   if (existsSync(path.join(standaloneDir, ".next/server/pages"))) {
     mkdirSync(path.join(outputNextDir, "server/pages"), {
@@ -141,6 +153,15 @@ File ${fullFilePath} does not exist
     }
   };
 
+  if (existsSync(path.join(dotNextDir, MIDDLEWARE_TRACE_FILE))) {
+    // We still need to copy the nft.json file so that computeCopyFilesForPage doesn't throw
+    copyFileSync(
+      path.join(dotNextDir, MIDDLEWARE_TRACE_FILE),
+      path.join(standaloneNextDir, MIDDLEWARE_TRACE_FILE),
+    );
+    computeCopyFilesForPage("middleware");
+  }
+
   const hasPageDir = routes.some((route) => route.startsWith("pages/"));
   const hasAppDir = routes.some((route) => route.startsWith("app/"));
 

packages/open-next/src/build/createMiddleware.ts

@@ -1,6 +1,7 @@
 import fs from "node:fs";
 import path from "node:path";
 
+import { loadFunctionsConfigManifest } from "config/util.js";
 import logger from "../logger.js";
 import type {
   MiddlewareInfo,
@@ -9,6 +10,10 @@ import type {
 import { buildEdgeBundle } from "./edge/createEdgeBundle.js";
 import * as buildHelper from "./helper.js";
 import { installDependencies } from "./installDeps.js";
+import {
+  buildBundledNodeMiddleware,
+  buildExternalNodeMiddleware,
+} from "./middleware/buildNodeMiddleware.js";
 
 /**
  * Compiles the middleware bundle.
@@ -32,10 +37,24 @@ export async function createMiddleware(
     ),
   ) as MiddlewareManifest;
 
-  const middlewareInfo = middlewareManifest.middleware["/"] as
+  const edgeMiddlewareInfo = middlewareManifest.middleware["/"] as
     | MiddlewareInfo
     | undefined;
 
+  if (!edgeMiddlewareInfo) {
+    // If there is no middleware info, it might be a node middleware
+    const functionsConfigManifest = loadFunctionsConfigManifest(
+      path.join(appBuildOutputPath, ".next"),
+    );
+
+    if (functionsConfigManifest?.functions["/_middleware"]) {
+      await (config.middleware?.external
+        ? buildExternalNodeMiddleware(options)
+        : buildBundledNodeMiddleware(options));
+      return;
+    }
+  }
+
   if (config.middleware?.external) {
     const outputPath = path.join(outputDir, "middleware");
     fs.mkdirSync(outputPath, { recursive: true });
@@ -55,7 +74,7 @@ export async function createMiddleware(
         "middleware.js",
       ),
       outfile: path.join(outputPath, "handler.mjs"),
-      middlewareInfo,
+      middlewareInfo: edgeMiddlewareInfo,
       options,
       overrides: {
         ...config.middleware.override,
@@ -77,7 +96,7 @@ export async function createMiddleware(
         "edgeFunctionHandler.js",
       ),
       outfile: path.join(options.buildDir, "middleware.mjs"),
-      middlewareInfo,
+      middlewareInfo: edgeMiddlewareInfo,
       options,
       onlyBuildOnce: true,
       name: "middleware",

packages/open-next/src/build/createServerBundle.ts

@@ -153,13 +153,13 @@ async function generateBundle(
   buildHelper.copyEnvFile(appBuildOutputPath, packagePath, outputPath);
 
   // Copy all necessary traced files
-  await copyTracedFiles(
-    appBuildOutputPath,
+  await copyTracedFiles({
+    buildOutputPath: appBuildOutputPath,
     packagePath,
-    outputPath,
-    fnOptions.routes ?? ["app/page.tsx"],
-    isBundled,
-  );
+    outputDir: outputPath,
+    routes: fnOptions.routes ?? ["app/page.tsx"],
+    bundledNextServer: isBundled,
+  });
 
   // Build Lambda code
   // note: bundle in OpenNext package b/c the adapter relies on the

packages/open-next/src/build/edge/createEdgeBundle.ts

@@ -16,6 +16,7 @@ import type {
 import type { OriginResolver } from "types/overrides.js";
 import logger from "../../logger.js";
 import { openNextEdgePlugins } from "../../plugins/edge.js";
+import { openNextExternalMiddlewarePlugin } from "../../plugins/externalMiddleware.js";
 import { openNextReplacementPlugin } from "../../plugins/replacement.js";
 import { openNextResolvePlugin } from "../../plugins/resolve.js";
 import { getCrossPlatformPathRegex } from "../../utils/regex.js";
@@ -88,14 +89,12 @@ export async function buildEdgeBundle({
           target: getCrossPlatformPathRegex("adapters/middleware.js"),
           deletes: includeCache ? [] : ["includeCacheInMiddleware"],
         }),
+        openNextExternalMiddlewarePlugin(
+          path.join(options.openNextDistDir, "core/edgeFunctionHandler.js"),
+        ),
         openNextEdgePlugins({
           middlewareInfo,
           nextDir: path.join(options.appBuildOutputPath, ".next"),
-          edgeFunctionHandlerPath: path.join(
-            options.openNextDistDir,
-            "core",
-            "edgeFunctionHandler.js",
-          ),
           isInCloudfare,
         }),
       ],

packages/open-next/src/build/middleware/buildNodeMiddleware.ts

@@ -0,0 +1,138 @@
+import fs from "node:fs";
+import path from "node:path";
+
+import type {
+  IncludedOriginResolver,
+  LazyLoadedOverride,
+  OverrideOptions,
+} from "types/open-next.js";
+import type { OriginResolver } from "types/overrides.js";
+import { getCrossPlatformPathRegex } from "utils/regex.js";
+import { openNextExternalMiddlewarePlugin } from "../../plugins/externalMiddleware.js";
+import { openNextReplacementPlugin } from "../../plugins/replacement.js";
+import { openNextResolvePlugin } from "../../plugins/resolve.js";
+import { copyTracedFiles } from "../copyTracedFiles.js";
+import * as buildHelper from "../helper.js";
+import { installDependencies } from "../installDeps.js";
+
+type Override = OverrideOptions & {
+  originResolver?: LazyLoadedOverride<OriginResolver> | IncludedOriginResolver;
+};
+
+export async function buildExternalNodeMiddleware(
+  options: buildHelper.BuildOptions,
+) {
+  const { appBuildOutputPath, config, outputDir } = options;
+  if (!config.middleware?.external) {
+    throw new Error(
+      "This function should only be called for external middleware",
+    );
+  }
+  const outputPath = path.join(outputDir, "middleware");
+  fs.mkdirSync(outputPath, { recursive: true });
+
+  // Copy open-next.config.mjs
+  buildHelper.copyOpenNextConfig(
+    options.buildDir,
+    outputPath,
+    await buildHelper.isEdgeRuntime(config.middleware.override),
+  );
+  const overrides = {
+    ...config.middleware.override,
+    originResolver: config.middleware.originResolver,
+  };
+  const includeCache = config.dangerous?.enableCacheInterception;
+  const packagePath = buildHelper.getPackagePath(options);
+
+  // TODO: change this so that we don't copy unnecessary files
+  await copyTracedFiles({
+    buildOutputPath: appBuildOutputPath,
+    packagePath,
+    outputDir: outputPath,
+    routes: [],
+    bundledNextServer: false,
+    skipServerFiles: true,
+  });
+
+  function override<T extends keyof Override>(target: T) {
+    return typeof overrides?.[target] === "string"
+      ? overrides[target]
+      : undefined;
+  }
+
+  // Bundle middleware
+  await buildHelper.esbuildAsync(
+    {
+      entryPoints: [
+        path.join(options.openNextDistDir, "adapters", "middleware.js"),
+      ],
+      outfile: path.join(outputPath, "handler.mjs"),
+      external: ["./.next/*"],
+      platform: "node",
+      plugins: [
+        openNextResolvePlugin({
+          overrides: {
+            wrapper: override("wrapper") ?? "aws-lambda",
+            converter: override("converter") ?? "aws-cloudfront",
+            ...(includeCache
+              ? {
+                  tagCache: override("tagCache") ?? "dynamodb-lite",
+                  incrementalCache: override("incrementalCache") ?? "s3-lite",
+                  queue: override("queue") ?? "sqs-lite",
+                }
+              : {}),
+            originResolver: override("originResolver") ?? "pattern-env",
+            proxyExternalRequest: override("proxyExternalRequest") ?? "node",
+          },
+          fnName: "middleware",
+        }),
+        openNextReplacementPlugin({
+          name: "externalMiddlewareOverrides",
+          target: getCrossPlatformPathRegex("adapters/middleware.js"),
+          deletes: includeCache ? [] : ["includeCacheInMiddleware"],
+        }),
+        openNextExternalMiddlewarePlugin(
+          path.join(
+            options.openNextDistDir,
+            "core",
+            "nodeMiddlewareHandler.js",
+          ),
+        ),
+      ],
+      banner: {
+        js: [
+          `globalThis.monorepoPackagePath = '${packagePath}';`,
+          "import process from 'node:process';",
+          "import { Buffer } from 'node:buffer';",
+          "import { AsyncLocalStorage } from 'node:async_hooks';",
+          "import { createRequire as topLevelCreateRequire } from 'module';",
+          "const require = topLevelCreateRequire(import.meta.url);",
+          "import bannerUrl from 'url';",
+          "const __dirname = bannerUrl.fileURLToPath(new URL('.', import.meta.url));",
+        ].join(""),
+      },
+    },
+    options,
+  );
+
+  // Do we need to copy or do something with env file here?
+
+  installDependencies(outputPath, config.middleware?.install);
+}
+
+export async function buildBundledNodeMiddleware(
+  options: buildHelper.BuildOptions,
+) {
+  await buildHelper.esbuildAsync(
+    {
+      entryPoints: [
+        path.join(options.openNextDistDir, "core/nodeMiddlewareHandler.js"),
+      ],
+      external: ["./.next/*"],
+      outfile: path.join(options.buildDir, "middleware.mjs"),
+      bundle: true,
+      platform: "node",
+    },
+    options,
+  );
+}