fix: make RDP drive redirection writable on the stock deployment (#1333)

* fix: make RDP drive redirection writable on the stock deployment

The default drive-path was /drive on the guacd side, which the official
guacd image cannot create as its non-root user, so every upload was
refused with guacd's raw "FAIL (CANNOT OPEN)" ack. Default to
GUACD_DRIVE_PATH (set to the shared termix-data volume in compose) with
one folder per user, and explain guacd's refusal in the file browser.

* style: format RDP drive settings

src/backend/hosts/guacamole/drive-settings.ts

@@ -0,0 +1,29 @@
+export const GUACD_DRIVE_PATH_ENV = "GUACD_DRIVE_PATH";
+const DEFAULT_DRIVE_ROOT = "/drive";
+
+/**
+ * Fills in where guacd keeps the files behind RDP drive redirection.
+ *
+ * The folder lives on the guacd host, not on Termix's - with the stock
+ * compose it is a directory in the shared termix-data volume, configured
+ * through GUACD_DRIVE_PATH. Each user gets a folder of their own underneath:
+ * a shared drive would show everyone's uploads to everyone else. A host that
+ * names its own drive-path keeps it.
+ */
+export function withDriveSettings(
+  guacConfig: Record<string, unknown>,
+  userId: string,
+  env: NodeJS.ProcessEnv = process.env,
+): Record<string, unknown> {
+  if (!guacConfig["enable-drive"] || guacConfig["drive-path"]) {
+    return guacConfig;
+  }
+  const root = (
+    env[GUACD_DRIVE_PATH_ENV]?.trim() || DEFAULT_DRIVE_ROOT
+  ).replace(/\/+$/, "");
+  return {
+    ...guacConfig,
+    "drive-path": `${root}/${userId}`,
+    "create-drive-path": true,
+  };
+}

src/backend/hosts/guacamole/routes.ts

@@ -2,6 +2,7 @@ import { getErrorMessage } from "../../utils/error-message.js";
 import express from "express";
 import { GuacamoleTokenService } from "./token-service.js";
 import { withRecordingSettings } from "./recording-settings.js";
+import { withDriveSettings } from "./drive-settings.js";
 import { guacLogger } from "../../utils/logger.js";
 import { AuthManager } from "../../utils/auth-manager.js";
 import { PermissionManager } from "../../utils/permission-manager.js";
@@ -658,10 +659,7 @@ router.post(
 
       switch (connectionType) {
         case "rdp":
-          if (guacConfig["enable-drive"] && !guacConfig["drive-path"]) {
-            guacConfig["drive-path"] = "/drive";
-            guacConfig["create-drive-path"] = true;
-          }
+          guacConfig = withDriveSettings(guacConfig, userId);
           token = tokenService.createRdpToken(
             hostname,
             username,

src/backend/tests/hosts/guacamole/drive-settings.test.ts

@@ -0,0 +1,34 @@
+import { describe, expect, it } from "vitest";
+import { withDriveSettings } from "../../../hosts/guacamole/drive-settings.js";
+
+describe("withDriveSettings", () => {
+  it("gives each user a folder under GUACD_DRIVE_PATH and creates it", () => {
+    expect(
+      withDriveSettings({ "enable-drive": true }, "user-1", {
+        GUACD_DRIVE_PATH: "/termix-data/rdp-drive/",
+      }),
+    ).toEqual({
+      "enable-drive": true,
+      "drive-path": "/termix-data/rdp-drive/user-1",
+      "create-drive-path": true,
+    });
+  });
+
+  it("falls back to /drive when the environment says nothing", () => {
+    expect(
+      withDriveSettings({ "enable-drive": true }, "user-1", {}),
+    ).toMatchObject({ "drive-path": "/drive/user-1" });
+  });
+
+  it("leaves a host-chosen drive-path alone", () => {
+    const config = { "enable-drive": true, "drive-path": "/mnt/share" };
+    expect(
+      withDriveSettings(config, "user-1", { GUACD_DRIVE_PATH: "/x" }),
+    ).toBe(config);
+  });
+
+  it("does nothing when the drive is not enabled", () => {
+    const config = { "enable-drive": false };
+    expect(withDriveSettings(config, "user-1")).toBe(config);
+  });
+});