pathProxy.ts: Implement --proxy-path-passthrough

Closes coder#2222

src/node/cli.ts

@@ -50,6 +50,7 @@ export interface Args extends VsArgs {
   "show-versions"?: boolean
   "uninstall-extension"?: string[]
   "proxy-domain"?: string[]
+  "proxy-path-passthrough"?: boolean
   locale?: string
   _: string[]
   "reuse-window"?: boolean
@@ -172,6 +173,10 @@ const options: Options<Required<Args>> = {
   "uninstall-extension": { type: "string[]", description: "Uninstall a VS Code extension by id." },
   "show-versions": { type: "boolean", description: "Show VS Code extension versions." },
   "proxy-domain": { type: "string[]", description: "Domain used for proxying ports." },
+  "proxy-path-passthrough": {
+    type: "boolean",
+    description: "Whether the path proxy should leave the /proxy/<port> in the request path when proxying.",
+  },
   "ignore-last-opened": {
     type: "boolean",
     short: "e",

src/node/routes/pathProxy.ts

@@ -8,12 +8,12 @@ import { Router as WsRouter } from "../wsRouter"
 
 export const router = Router()
 
-const getProxyTarget = (req: Request, rewrite: boolean): string => {
-  if (rewrite) {
-    const query = qs.stringify(req.query)
-    return `http://0.0.0.0:${req.params.port}/${req.params[0] || ""}${query ? `?${query}` : ""}`
+const getProxyTarget = (req: Request, passthroughPath: boolean): string => {
+  if (passthroughPath) {
+    return `http://0.0.0.0:${req.params.port}/${req.originalUrl}`
   }
-  return `http://0.0.0.0:${req.params.port}/${req.originalUrl}`
+  const query = qs.stringify(req.query)
+  return `http://0.0.0.0:${req.params.port}/${req.params[0] || ""}${query ? `?${query}` : ""}`
 }
 
 router.all("/(:port)(/*)?", (req, res) => {
@@ -33,7 +33,7 @@ router.all("/(:port)(/*)?", (req, res) => {
 
   proxy.web(req, res, {
     ignorePath: true,
-    target: getProxyTarget(req, true),
+    target: getProxyTarget(req, req.args["proxy-path-passthrough"] || false),
   })
 })
 
@@ -42,6 +42,6 @@ export const wsRouter = WsRouter()
 wsRouter.ws("/(:port)(/*)?", ensureAuthenticated, (req) => {
   proxy.ws(req, req.ws, req.head, {
     ignorePath: true,
-    target: getProxyTarget(req, true),
+    target: getProxyTarget(req, req.args["proxy-path-passthrough"] || false),
   })
 })