update format of HANDLER

Author: cnuss

src/bootstrap.ts

@@ -1,7 +1,6 @@
 import { ChildProcess, spawn } from "child_process";
-import which from "which";
 import { routeEvents } from "./routing";
-import { log } from "./log";
+import { info, log } from "./log";
 
 const { _HANDLER, IS_OFFLINE, AWS_LAMBDA_RUNTIME_API } = process.env;
 
@@ -16,34 +15,32 @@ export const bootstrap = async (): Promise<void> => {
 
   log("Bootstraping", { _HANDLER, IS_OFFLINE, AWS_LAMBDA_RUNTIME_API });
 
-  let handler: URL | undefined = undefined;
-  let bin: string;
-  let endpoint: string | undefined = undefined;
-
   // handler is in the format of
-  // - `{some-bin}:http://localhost:{the-bins-port} (will start some-bin, and forward requests to the http server)
+  // - `{some-bin}@http://localhost:{the-bins-port} (will start some-bin, and forward requests to the http server)
   // - `http://localhost:{some-port}` (will forward the request to the http server)
   // - `{some-bin}` (will forward the event to the bin)
 
-  try {
-    handler = new URL(_HANDLER);
-    bin = handler.protocol.slice(0, -1);
-    endpoint = handler.toString();
-    log("Found protocol in handler", { bin, endpoint });
-  } catch (e) {
-    log("No protocol found in handler", { _HANDLER });
-    bin = _HANDLER;
-  }
+  let [bin, endpoint] = _HANDLER.split(/(?<=^[^@]*)@/) as [
+    string | undefined,
+    string | undefined | URL
+  ];
 
   let childProcess: ChildProcess | undefined = undefined;
 
-  if (handler && bin !== "http" && bin !== "https") {
-    log("Starting child process", { bin, endpoint });
+  if (bin && !endpoint) {
+    try {
+      endpoint = new URL(bin).toString();
+      bin = undefined;
+    } catch (e) {}
+  }
 
-    endpoint = handler.pathname;
+  if (bin && endpoint) {
+    log("Starting child process", { bin });
 
     const subcommand = IS_OFFLINE === "true" ? "dev" : "start";
 
+    info(`Running: \`${bin} ${subcommand}\``);
+
     childProcess = spawn(bin, [subcommand], {
       detached: true,
       stdio: "inherit",
@@ -55,10 +52,9 @@ export const bootstrap = async (): Promise<void> => {
     log("Started child process", { bin, subcommand, pid: childProcess.pid });
   }
 
-  try {
-    log("Checking if bin is in PATH", { bin });
-    await which(bin, { all: false });
+  endpoint = endpoint ? new URL(endpoint) : undefined;
 
+  try {
     log("Routing events", { bin, endpoint });
     await routeEvents(AWS_LAMBDA_RUNTIME_API, bin, endpoint);
   } catch (e) {

src/log.ts

@@ -1,9 +1,16 @@
 import packageJson from "../package.json";
 
+export const info = (message: any, obj?: Record<string, any>): void => {
+  console.log(
+    `[${packageJson.name}@${packageJson.version}] ${message}`,
+    obj ? JSON.stringify(obj) : undefined
+  );
+};
+
 export const log = (message: any, obj?: Record<string, any>): void => {
   if (!process.env.SLY_DEBUG) return;
   console.log(
     `[${packageJson.name}@${packageJson.version}] ${message}`,
-    JSON.stringify(obj)
+    obj ? JSON.stringify(obj) : undefined
   );
 };

src/proxy.ts

@@ -31,13 +31,13 @@ function convertHeaders(
 }
 
 const waitForEndpoint = async (
-  endpoint: string,
+  endpoint: URL,
   deadline: number
 ): Promise<{ deadline: number }> => {
   const start = Date.now();
-  const url = new URL(endpoint);
-  const hostname = url.hostname;
-  const port = parseInt(url.port, 10) || (url.protocol === "https:" ? 443 : 80);
+  const hostname = endpoint.hostname;
+  const port =
+    parseInt(endpoint.port, 10) || (endpoint.protocol === "https:" ? 443 : 80);
 
   return new Promise((resolve) => {
     const socket = new net.Socket();

src/routing.ts

@@ -5,8 +5,8 @@ import { log } from "./log";
 
 export const routeEvents = async (
   runtimeApi: string,
-  bin: string,
-  endpoint?: string
+  bin?: string,
+  endpoint?: URL
 ): Promise<void> => {
   log("Waiting for next event from Lambda Runtime API", { runtimeApi });
 
@@ -33,7 +33,7 @@ export const routeEvents = async (
 
   let payload: any | undefined = undefined;
 
-  if (!endpoint) {
+  if (bin && !endpoint) {
     log("No endpoint specified, executing bin", { bin });
 
     const { execa } = await import("execa");
@@ -45,7 +45,7 @@ export const routeEvents = async (
     log("Bin execution complete", { bin, stdout });
 
     payload = JSON.parse(stdout);
-  } else {
+  } else if (endpoint) {
     log("Endpoint specified, proxying request", { endpoint });
 
     const request: EndpointRequest = {
@@ -58,6 +58,17 @@ export const routeEvents = async (
     payload = (await endpointProxy(request)).payload;
 
     log("Proxy request complete", { endpoint, payload });
+  } else {
+    throw new Error(
+      `
+Missing bin and handler on _HANDLER: ${process.env._HANDLER}. 
+Expected format: {bin}@{endpoint} or {bin} or {endpoint}:
+ - next@http://localhost:3000
+ - /usr/bin/app@http://localhost:3000
+ - http://localhost:3000
+ - /usr/bin/app
+`
+    );
   }
 
   await axios.post(

src/types.ts

@@ -1,6 +1,6 @@
 export type EndpointRequest = {
   requestId: string;
-  endpoint: string;
+  endpoint: URL;
   event: any;
   initialDeadline: number;
 };