Add a user-accessible hook for dumping debug code into an install

Summary:
Currently, there's no easy way for me to tell a user "run this code from the webserver and tell me what it says". Sometimes installs can add new .php files to, e.g., `webroot/rsrc/`, but this is setup-dependent and not universal. Generally I resort to saying "put this into index.php", but that's error prone and not acceptable on active installs.

Add a "debug" controller so I can instead say "put this into support/debug.php, then visit /debug/".

Test Plan: Visited /debug/ with and without support/debug.php files. Visited /staus/.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D5212

.gitignore

@@ -27,3 +27,6 @@
 
 # Impact Font
 /resources/font/impact.ttf
+
+# User-accessible hook for adhoc debugging scripts
+/support/debug.php

src/__phutil_library_map__.php

@@ -831,6 +831,7 @@ phutil_register_library_map(array(
     'PhabricatorDaemonLogListView' => 'applications/daemon/view/PhabricatorDaemonLogListView.php',
     'PhabricatorDaemonLogViewController' => 'applications/daemon/controller/PhabricatorDaemonLogViewController.php',
     'PhabricatorDaemonReference' => 'infrastructure/daemon/control/PhabricatorDaemonReference.php',
+    'PhabricatorDebugController' => 'applications/system/PhabricatorDebugController.php',
     'PhabricatorDefaultFileStorageEngineSelector' => 'applications/files/engineselector/PhabricatorDefaultFileStorageEngineSelector.php',
     'PhabricatorDefaultSearchEngineSelector' => 'applications/search/selector/PhabricatorDefaultSearchEngineSelector.php',
     'PhabricatorDeveloperConfigOptions' => 'applications/config/option/PhabricatorDeveloperConfigOptions.php',
@@ -1307,7 +1308,7 @@ phutil_register_library_map(array(
     'PhabricatorSortTableExample' => 'applications/uiexample/examples/PhabricatorSortTableExample.php',
     'PhabricatorSourceCodeView' => 'view/layout/PhabricatorSourceCodeView.php',
     'PhabricatorStandardPageView' => 'view/page/PhabricatorStandardPageView.php',
-    'PhabricatorStatusController' => 'applications/status/PhabricatorStatusController.php',
+    'PhabricatorStatusController' => 'applications/system/PhabricatorStatusController.php',
     'PhabricatorStorageFixtureScopeGuard' => 'infrastructure/testing/fixture/PhabricatorStorageFixtureScopeGuard.php',
     'PhabricatorStorageManagementAPI' => 'infrastructure/storage/management/PhabricatorStorageManagementAPI.php',
     'PhabricatorStorageManagementDatabasesWorkflow' => 'infrastructure/storage/management/workflow/PhabricatorStorageManagementDatabasesWorkflow.php',
@@ -2337,6 +2338,7 @@ phutil_register_library_map(array(
     'PhabricatorDaemonLogListController' => 'PhabricatorDaemonController',
     'PhabricatorDaemonLogListView' => 'AphrontView',
     'PhabricatorDaemonLogViewController' => 'PhabricatorDaemonController',
+    'PhabricatorDebugController' => 'PhabricatorController',
     'PhabricatorDefaultFileStorageEngineSelector' => 'PhabricatorFileStorageEngineSelector',
     'PhabricatorDefaultSearchEngineSelector' => 'PhabricatorSearchEngineSelector',
     'PhabricatorDeveloperConfigOptions' => 'PhabricatorApplicationConfigOptions',

src/aphront/configuration/AphrontDefaultApplicationConfiguration.php

@@ -109,6 +109,8 @@ class AphrontDefaultApplicationConfiguration
           'testpaymentform/' => 'PhortuneStripeTestPaymentFormController',
         ),
       ),
+
+      '/debug/' => 'PhabricatorDebugController',
     );
   }
 

src/applications/system/PhabricatorDebugController.php

@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * This controller eases debugging of application problems that don't repro
+ * locally by allowing installs to add arbitrary debugging code easily. To use
+ * it:
+ *
+ *  - Write some diagnostic script.
+ *  - Instruct the user to install it in `/support/debug.php`.
+ *  - Tell them to visit `/debug/`.
+ */
+final class PhabricatorDebugController extends PhabricatorController {
+
+  public function shouldRequireLogin() {
+    return false;
+  }
+
+  public function processRequest() {
+    if (!Filesystem::pathExists($this->getDebugFilePath())) {
+      return new Aphront404Response();
+    }
+
+    $request = $this->getRequest();
+    $user = $request->getUser();
+
+    ob_start();
+    require_once $this->getDebugFilePath();
+    $out = ob_get_clean();
+
+    $response = new AphrontWebpageResponse();
+    $response->setContent(hsprintf('<pre>%s</pre>', $out));
+    return $response;
+  }
+
+  private function getDebugFilePath() {
+    $root = dirname(phutil_get_library_root('phabricator'));
+    return $root.'/support/debug.php';
+  }
+}