Add support for devtools inspector protocol (#426)

Adds a new `inspectorPort` option, passed to `workerd`'s
`--inspector-addr`. Also disables `--verbose` by default, unless the
`verbose: true` option is set, as we don't want logging by default
if we could use the inspector for this instead.

Author: mrbbot

packages/tre/src/index.ts

@@ -31,6 +31,7 @@ import {
   Config,
   Runtime,
   RuntimeConstructor,
+  RuntimeOptions,
   Service,
   Socket,
   Worker_Binding,
@@ -229,11 +230,16 @@ export class Miniflare {
     const loopbackPort = address.port;
 
     // Start runtime
-    const host = this.#sharedOpts.core.host ?? "127.0.0.1";
-    const port = this.#sharedOpts.core.port ?? (await getPort({ port: 8787 }));
-    this.#runtime = new this.#runtimeConstructor(host, port, loopbackPort);
+    const opts: RuntimeOptions = {
+      entryHost: this.#sharedOpts.core.host ?? "127.0.0.1",
+      entryPort: this.#sharedOpts.core.port ?? (await getPort({ port: 8787 })),
+      loopbackPort,
+      inspectorPort: this.#sharedOpts.core.inspectorPort,
+      verbose: this.#sharedOpts.core.verbose,
+    };
+    this.#runtime = new this.#runtimeConstructor(opts);
     this.#removeRuntimeExitHook = exitHook(() => void this.#runtime?.dispose());
-    this.#runtimeEntryURL = new URL(`http://127.0.0.1:${port}`);
+    this.#runtimeEntryURL = new URL(`http://127.0.0.1:${opts.entryPort}`);
 
     const config = await this.#assembleConfig();
     assert(config !== undefined);

packages/tre/src/plugins/core/index.ts

@@ -49,12 +49,17 @@ export const CoreOptionsSchema = z.object({
   wasmBindings: z.record(z.string()).optional(),
   textBlobBindings: z.record(z.string()).optional(),
   dataBlobBindings: z.record(z.string()).optional(),
+  // TODO: add support for workerd network/external/disk services here
   serviceBindings: z.record(z.union([z.string(), ServiceFetch])).optional(),
 });
 
 export const CoreSharedOptionsSchema = z.object({
   host: z.string().optional(),
   port: z.number().optional(),
+
+  inspectorPort: z.number().optional(),
+  verbose: z.boolean().optional(),
+
   // TODO: add back validation of cf object
   cf: z.union([z.boolean(), z.string(), z.record(z.any())]).optional(),
 });

packages/tre/src/runtime/index.ts

@@ -10,39 +10,49 @@ import workerdPath, {
 import { SERVICE_LOOPBACK, SOCKET_ENTRY } from "../plugins";
 import { Awaitable, MiniflareCoreError } from "../shared";
 
+export interface RuntimeOptions {
+  entryHost: string;
+  entryPort: number;
+  loopbackPort: number;
+  inspectorPort?: number;
+  verbose?: boolean;
+}
+
 export abstract class Runtime {
-  constructor(
-    protected readonly entryHost: string,
-    protected readonly entryPort: number,
-    protected readonly loopbackPort: number
-  ) {}
+  constructor(protected readonly opts: RuntimeOptions) {}
 
   abstract updateConfig(configBuffer: Buffer): Awaitable<void>;
   abstract get exitPromise(): Promise<void> | undefined;
   abstract dispose(): Awaitable<void>;
+
+  protected getCommonArgs(): string[] {
+    const args: string[] = [
+      "serve",
+      // Required to use binary capnp config
+      "--binary",
+      // Required to use compatibility flags without a default-on date,
+      // (e.g. "streams_enable_constructors"), see https://github.com/cloudflare/workerd/pull/21
+      "--experimental",
+    ];
+    if (this.opts.inspectorPort !== undefined) {
+      // Required to enable the V8 inspector
+      args.push(`--inspector-addr=127.0.0.1:${this.opts.inspectorPort}`);
+    }
+    if (this.opts.verbose) {
+      args.push("--verbose");
+    }
+    return args;
+  }
 }
 
 export interface RuntimeConstructor {
-  new (entryHost: string, entryPort: number, loopbackPort: number): Runtime;
+  new (opts: RuntimeOptions): Runtime;
 
   isSupported(): boolean;
   supportSuggestion: string;
   description: string;
 }
 
-const COMMON_RUNTIME_ARGS = [
-  "serve",
-  // Required to use binary capnp config
-  "--binary",
-  // Required to display `console.log()` output
-  "--verbose",
-  // Required to use compatibility flags without a default-on date,
-  // (e.g. "streams_enable_constructors"), see https://github.com/cloudflare/workerd/pull/21
-  "--experimental",
-];
-// `__dirname` relative to bundled output `dist/src/index.js`
-const RESTART_PATH = path.resolve(__dirname, "..", "..", "lib", "restart.sh");
-
 function waitForExit(process: childProcess.ChildProcess): Promise<void> {
   return new Promise((resolve) => {
     process.once("exit", () => resolve());
@@ -84,8 +94,8 @@ class NativeRuntime extends Runtime {
   #process?: childProcess.ChildProcess;
   #processExitPromise?: Promise<void>;
 
-  constructor(entryHost: string, entryPort: number, loopbackPort: number) {
-    super(entryHost, entryPort, loopbackPort);
+  constructor(opts: RuntimeOptions) {
+    super(opts);
     const [command, ...args] = this.getCommand();
     this.#command = command;
     this.#args = args;
@@ -94,9 +104,9 @@ class NativeRuntime extends Runtime {
   getCommand(): string[] {
     return [
       workerdPath,
-      ...COMMON_RUNTIME_ARGS,
-      `--socket-addr=${SOCKET_ENTRY}=${this.entryHost}:${this.entryPort}`,
-      `--external-addr=${SERVICE_LOOPBACK}=127.0.0.1:${this.loopbackPort}`,
+      ...this.getCommonArgs(),
+      `--socket-addr=${SOCKET_ENTRY}=${this.opts.entryHost}:${this.opts.entryPort}`,
+      `--external-addr=${SERVICE_LOOPBACK}=127.0.0.1:${this.opts.loopbackPort}`,
       // TODO: consider adding support for unix sockets?
       // `--socket-fd=${SOCKET_ENTRY}=${this.entryPort}`,
       // `--external-addr=${SERVICE_LOOPBACK}=${this.loopbackPort}`,
@@ -150,6 +160,9 @@ class WSLRuntime extends NativeRuntime {
   }
 }
 
+// `__dirname` relative to bundled output `dist/src/index.js`
+const RESTART_PATH = path.resolve(__dirname, "..", "..", "lib", "restart.sh");
+
 class DockerRuntime extends Runtime {
   static isSupported() {
     const result = childProcess.spawnSync("docker", ["--version"]); // TODO: check daemon running too?
@@ -191,13 +204,13 @@ class DockerRuntime extends Runtime {
         `--volume=${RESTART_PATH}:/restart.sh`,
         `--volume=${workerdPath}:/runtime`,
         `--volume=${this.#configPath}:/miniflare-config.bin`,
-        `--publish=${this.entryHost}:${this.entryPort}:8787`,
+        `--publish=${this.opts.entryHost}:${this.opts.entryPort}:8787`,
         "debian:bullseye-slim",
         "/restart.sh",
         "/runtime",
-        ...COMMON_RUNTIME_ARGS,
+        ...this.getCommonArgs(),
         `--socket-addr=${SOCKET_ENTRY}=*:8787`,
-        `--external-addr=${SERVICE_LOOPBACK}=host.docker.internal:${this.loopbackPort}`,
+        `--external-addr=${SERVICE_LOOPBACK}=host.docker.internal:${this.opts.loopbackPort}`,
         "/miniflare-config.bin",
       ],
       {