Route internal conduit calls if other hosts available

Summary:
Ref T2785

Looks for hosts in `conduit.servers` config and if any exist route any conduit calls through any one of the hosts.

Test Plan:
Make some curl calls to public methods (`conduit.ping`), watch the access log for two requests. Make some calls from the UI that require authentication, watch the access log a bit more.

Also ran the unit tests.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2785

Differential Revision: https://secure.phabricator.com/D5970

src/__phutil_library_map__.php

@@ -830,6 +830,7 @@ phutil_register_library_map(array(
     'PhabricatorChatLogQuery' => 'applications/chatlog/PhabricatorChatLogQuery.php',
     'PhabricatorConduitAPIController' => 'applications/conduit/controller/PhabricatorConduitAPIController.php',
     'PhabricatorConduitCertificateToken' => 'applications/conduit/storage/PhabricatorConduitCertificateToken.php',
+    'PhabricatorConduitConfigOptions' => 'applications/conduit/config/PhabricatorConduitConfigOptions.php',
     'PhabricatorConduitConnectionLog' => 'applications/conduit/storage/PhabricatorConduitConnectionLog.php',
     'PhabricatorConduitConsoleController' => 'applications/conduit/controller/PhabricatorConduitConsoleController.php',
     'PhabricatorConduitController' => 'applications/conduit/controller/PhabricatorConduitController.php',
@@ -2601,6 +2602,7 @@ phutil_register_library_map(array(
     'PhabricatorChatLogQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorConduitAPIController' => 'PhabricatorConduitController',
     'PhabricatorConduitCertificateToken' => 'PhabricatorConduitDAO',
+    'PhabricatorConduitConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorConduitConnectionLog' => 'PhabricatorConduitDAO',
     'PhabricatorConduitConsoleController' => 'PhabricatorConduitController',
     'PhabricatorConduitController' => 'PhabricatorController',

src/aphront/configuration/AphrontApplicationConfiguration.php

@@ -117,14 +117,29 @@ abstract class AphrontApplicationConfiguration {
     $host         = $request->getHost();
     $base_uri     = PhabricatorEnv::getEnvConfig('phabricator.base-uri');
     $prod_uri     = PhabricatorEnv::getEnvConfig('phabricator.production-uri');
-    $file_uri = PhabricatorEnv::getEnvConfig('security.alternate-file-domain');
+    $file_uri     = PhabricatorEnv::getEnvConfig(
+      'security.alternate-file-domain');
+    $conduit_uris = PhabricatorEnv::getEnvConfig('conduit.servers');
+
+    $uris = array_merge(
+      array(
+        $base_uri,
+        $prod_uri,
+        $file_uri,
+      ),
+      $conduit_uris);
+
+    $host_match = false;
+    foreach ($uris as $uri) {
+      if ($host === id(new PhutilURI($uri))->getDomain()) {
+        $host_match = true;
+        break;
+      }
+    }
 
     // NOTE: If the base URI isn't defined yet, don't activate alternate
     // domains.
-    if ($base_uri &&
-        $host != id(new PhutilURI($base_uri))->getDomain() &&
-        $host != id(new PhutilURI($prod_uri))->getDomain() &&
-        $host != id(new PhutilURI($file_uri))->getDomain()) {
+    if ($base_uri && !$host_match) {
 
       try {
         $blog = id(new PhameBlogQuery())

src/applications/conduit/call/ConduitCall.php

@@ -13,10 +13,14 @@ final class ConduitCall {
   private $method;
   private $request;
   private $user;
+  private $servers;
+  private $forceLocal;
 
   public function __construct($method, array $params) {
     $this->method     = $method;
     $this->handler    = $this->buildMethodHandler($method);
+    $this->servers    = PhabricatorEnv::getEnvConfig('conduit.servers');
+    $this->forceLocal = false;
 
     $invalid_params = array_diff_key(
       $params,
@@ -27,6 +31,16 @@ final class ConduitCall {
         implode("', '", array_keys($invalid_params)) . "'.");
     }
 
+    if ($this->servers) {
+      $current_host = AphrontRequest::getHTTPHeader('HOST');
+      foreach ($this->servers as $server) {
+        if ($current_host === id(new PhutilURI($server))->getDomain()) {
+          $this->forceLocal = true;
+          break;
+        }
+      }
+    }
+
     $this->request = new ConduitAPIRequest($params);
   }
 
@@ -39,6 +53,15 @@ final class ConduitCall {
     return $this->user;
   }
 
+  public function setForceLocal($force_local) {
+    $this->forceLocal = $force_local;
+    return $this;
+  }
+
+  public function shouldForceLocal() {
+    return $this->forceLocal;
+  }
+
   public function shouldRequireAuthentication() {
     return $this->handler->shouldRequireAuthentication();
   }
@@ -64,8 +87,36 @@ final class ConduitCall {
       $this->request->setUser($this->getUser());
     }
 
+    if (!$this->shouldForceLocal() && $this->servers) {
+      $server = $this->pickRandomServer($this->servers);
+      $client = new ConduitClient($server);
+      $params = $this->request->getAllParameters();
+
+      $params["__conduit__"]["isProxied"] = true;
+
+      if ($this->handler->shouldRequireAuthentication()) {
+        $client->callMethodSynchronous(
+        'conduit.connect',
+        array(
+             'client'            => 'PhabricatorConduit',
+             'clientVersion'     => '1.0',
+             'user'              => $this->getUser()->getUserName(),
+             'certificate'       => $this->getUser()->getConduitCertificate(),
+             '__conduit__'       => $params["__conduit__"],
+        ));
+      }
+
+      return $client->callMethodSynchronous(
+        $this->method,
+        $params);
+    } else {
       return $this->handler->executeMethod($this->request);
     }
+  }
+
+  protected function pickRandomServer($servers) {
+    return $servers[array_rand($servers)];
+  }
 
   protected function buildMethodHandler($method) {
     $method_class = ConduitAPIMethod::getClassNameFromAPIMethodName($method);

src/applications/conduit/call/__tests__/ConduitCallTestCase.php

@@ -4,13 +4,15 @@ final class ConduitCallTestCase extends PhabricatorTestCase {
 
   public function testConduitPing() {
     $call = new ConduitCall('conduit.ping', array());
+    $call->setForceLocal(true);
     $result = $call->execute();
 
     $this->assertEqual(false, empty($result));
   }
 
   public function testConduitAuth() {
-    $call = new ConduitCall('user.whoami', array());
+    $call = new ConduitCall('user.whoami', array(), true);
+    $call->setForceLocal(true);
 
     $caught = null;
     try {

src/applications/conduit/config/PhabricatorConduitConfigOptions.php

@@ -0,0 +1,31 @@
+<?php
+
+final class PhabricatorConduitConfigOptions
+  extends PhabricatorApplicationConfigOptions {
+
+  public function getName() {
+    return pht("Conduit");
+  }
+
+  public function getDescription() {
+    return pht("Configure conduit.");
+  }
+
+  public function getOptions() {
+    return array(
+      $this->newOption("conduit.servers", "list<string>", array())
+        ->setLocked(true)
+        ->setSummary(pht("Servers that conduit can connect to."))
+        ->setDescription(
+            pht(
+              "Set an array of servers where conduit can connect to. This is ".
+              "an advanced option. Don't touch this unless you know what you ".
+              "are doing."))
+        ->addExample(
+          '["http://phabricator2.example.com/", '.
+          '"http://phabricator3.example.com/]"',
+           pht('Valid Setting')),
+    );
+  }
+
+}

src/applications/conduit/controller/PhabricatorConduitAPIController.php

@@ -35,7 +35,8 @@ final class PhabricatorConduitAPIController
       $metadata = idx($params, '__conduit__', array());
       unset($params['__conduit__']);
 
-      $call = new ConduitCall($method, $params);
+      $call = new ConduitCall(
+        $method, $params, idx($metadata, 'isProxied', false));
 
       $result = null;
 

src/applications/differential/conduit/ConduitAPI_differential_finishpostponedlinters_Method.php

@@ -98,6 +98,7 @@ final class ConduitAPI_differential_finishpostponedlinters_Method
         'diff_id' => $diff_id,
         'name' => 'arc:lint',
         'data' => json_encode($messages)));
+    $call->setForceLocal(true);
     $call->setUser($request->getUser());
     $call->execute();
     $call = new ConduitCall(
@@ -106,6 +107,7 @@ final class ConduitAPI_differential_finishpostponedlinters_Method
         'diff_id' => $diff_id,
         'name' => 'arc:lint-postponed',
         'data' => json_encode($postponed_linters)));
+    $call->setForceLocal(true);
     $call->setUser($request->getUser());
     $call->execute();