document the middleware

README.md

@@ -26,6 +26,12 @@ Prerequisite: golang installed
 
 Prerequisite: bun installed
 
+The environment variable `API_HOST` will need to be set for the middleware.
+Example `.env` in web's root:
+```
+API_HOST="http://localhost:8082/v1/"
+```
+
 1. `cd web`
 2. `bun install`
 

web/next.config.ts

@@ -3,15 +3,7 @@ import type { NextConfig } from "next";
 const nextConfig: NextConfig = {
     distDir: "build",
     output: "standalone",
-    rewrites: async () => {
+    images: {
-    	return [
-     		{
-				source: "/api/:path*",
-        		destination: "http://localhost:8082/v1/:path*"
-       		}
-     	]
-    },
-	images: {
 		remotePatterns: [
 			{
 				protocol: 'https',

web/src/app/middleware.ts

@@ -0,0 +1,13 @@
+import { NextRequest, NextResponse } from "next/server"
+
+export const config = {
+	matcher: ["/api/:path*"],
+}
+
+export function middleware(request: NextRequest) {
+	if (!process.env.API_HOST) {
+		throw new Error("env variable \"API_HOST\" is not set")
+	}
+	const url = new URL(process.env.API_HOST + request.nextUrl.pathname + request.nextUrl.search)
+	return NextResponse.rewrite(url, { request })
+}