Add static file serve for resources inside of data-directory (#19)

packages/server/src/server.ts

@@ -4,8 +4,11 @@ import { Server, ServerOptions } from "@coder/protocol/src/node/server";
 import { NewSessionMessage } from '@coder/protocol/src/proto';
 import { ChildProcess } from "child_process";
 import * as express from "express";
+import * as fs from "fs";
 import * as http from "http";
+import * as mime from "mime-types";
 import * as path from "path";
+import * as util from "util";
 import * as ws from "ws";
 import { forkModule } from "./vscode/bootstrapFork";
 
@@ -63,6 +66,43 @@ export const createApp = (registerMiddleware?: (app: express.Application) => voi
 
 	app.use(express.static(path.join(__dirname, "../build/web")));
 
+	app.get("/resource/:url(*)", async (req, res) => {
+		try {
+			const fullPath = `/${req.params.url}`;
+			const relative = path.relative(options!.dataDirectory, fullPath);
+			if (relative.startsWith("..")) {
+				return res.status(403).end();
+			}
+			const exists = await util.promisify(fs.exists)(fullPath);
+			if (!exists) {
+				res.status(404).end();
+				return;
+			}
+			const stat = await util.promisify(fs.stat)(fullPath);
+			if (!stat.isFile()) {
+				res.write("Resource must be a file.");
+				res.status(422);
+				res.end();
+
+				return;
+			}
+			let mimeType = mime.lookup(fullPath);
+			if (mimeType === false) {
+				mimeType = "application/octet-stream";
+			}
+			const content = await util.promisify(fs.readFile)(fullPath);
+
+			res.header("Content-Type", mimeType as string);
+			res.write(content);
+			res.status(200);
+			res.end();
+		} catch (ex) {
+			res.write(ex.toString());
+			res.status(500);
+			res.end();
+		}
+	});
+
 	return {
 		express: app,
 		server,