AU: Provide a D-Bus API for changing the update track.

update_engine_client.cc

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 
 #include <gflags/gflags.h>
 #include <glib.h>
 
 #include "update_engine/marshal.glibmarshal.h"
 #include "update_engine/dbus_constants.h"
 #include "update_engine/subprocess.h"
 #include "update_engine/utils.h"
 
 extern "C" {
 #include "update_engine/update_engine.dbusclient.h"
 }
 
 using chromeos_update_engine::kUpdateEngineServiceName;
 using chromeos_update_engine::kUpdateEngineServicePath;
 using chromeos_update_engine::kUpdateEngineServiceInterface;
 using chromeos_update_engine::utils::GetGErrorMessage;
 using std::string;
 
 DEFINE_string(app_version, "", "Force the current app version.");
 DEFINE_bool(check_for_update, false, "Initiate check for updates.");
 DEFINE_string(omaha_url, "", "The URL of the Omaha update server.");
 DEFINE_bool(reboot, false, "Initiate a reboot if needed.");
 DEFINE_bool(status, false, "Print the status to stdout.");
+DEFINE_string(track, "", "Permanently change the update track.");
 DEFINE_bool(update, false, "Forces an update and waits for its completion. "
             "Exit status is 0 if the update succeeded, and 1 otherwise.");
 DEFINE_bool(watch_for_updates, false,
             "Listen for status updates and print them to the screen.");
 
 namespace {
 
 bool GetProxy(DBusGProxy** out_proxy) {
   DBusGConnection* bus;
   DBusGProxy* proxy;
@@ skipping 129 matching lines @@
 
   gboolean rc =
       org_chromium_UpdateEngineInterface_reboot_if_needed(proxy, &error);
   // Reboot error code doesn't necessarily mean that a reboot
   // failed. For example, D-Bus may be shutdown before we receive the
   // result.
   LOG_IF(INFO, !rc) << "Reboot error message: " << GetGErrorMessage(error);
   return true;
 }
 
+void SetTrack(const string& track) {
+  DBusGProxy* proxy;
+  GError* error = NULL;
+
+  CHECK(GetProxy(&proxy));
+
+  gboolean rc =
+      org_chromium_UpdateEngineInterface_set_track(proxy,
+                                                   track.c_str(),
+                                                   &error);
+  CHECK_EQ(rc, true) << "Error setting the track: "
+                     << GetGErrorMessage(error);
+  LOG(INFO) << "TODO: Track permanently set to: " << track;
+}
+
 static gboolean CompleteUpdateSource(gpointer data) {
   string current_op;
   if (!GetStatus(&current_op) || current_op == "UPDATE_STATUS_IDLE") {
     LOG(ERROR) << "Update failed.";
     exit(1);
   }
   if (current_op == "UPDATE_STATUS_UPDATED_NEED_REBOOT") {
     LOG(INFO) << "Update succeeded -- reboot needed.";
     exit(0);
   }
@@ skipping 22 matching lines @@
 
   if (FLAGS_status) {
     LOG(INFO) << "Querying Update Engine status...";
     if (!GetStatus(NULL)) {
       LOG(FATAL) << "GetStatus failed.";
       return 1;
     }
     return 0;
   }
 
+  // First, update the track if requested.
+  if (!FLAGS_track.empty()) {
+    SetTrack(FLAGS_track);
+  }
+
   // Initiate an update check, if necessary.
   if (FLAGS_check_for_update ||
       FLAGS_update ||
       !FLAGS_app_version.empty() ||
       !FLAGS_omaha_url.empty()) {
     LOG_IF(WARNING, FLAGS_reboot) << "-reboot flag ignored.";
     string app_version = FLAGS_app_version;
     if (FLAGS_update && app_version.empty()) {
       app_version = "ForcedUpdate";
       LOG(INFO) << "Forcing an update by setting app_version to ForcedUpdate.";
@@ skipping 18 matching lines @@
     WatchForUpdates();  // Should never return.
     return 1;
   }
 
   if (FLAGS_reboot) {
     LOG(INFO) << "Requesting a reboot...";
     CHECK(RebootIfNeeded());
     return 0;
   }
 
-  LOG(INFO) << "No flags specified. Exiting.";
+  LOG(INFO) << "Done.";
   return 0;
 }