Daemonize (fork()) and install metrics_daemon in the image for execution.

src/platform/metrics_daemon/main.cc

Index: src/platform/metrics_daemon/main.cc
diff --git a/src/platform/metrics_daemon/main.cc b/src/platform/metrics_daemon/main.cc
index 1ee2080d3da389e0745f96bf2bb0fcc99304c9b3..10348a12030c7433c4c5cd3d989e7c240b4790f8 100644
--- a/src/platform/metrics_daemon/main.cc
+++ b/src/platform/metrics_daemon/main.cc
@@ -3,9 +3,14 @@
 // found in the LICENSE file.
 
 
+#include <gflags/gflags.h>
+
 #include "platform/metrics_daemon/metrics_daemon.h"
 
+DEFINE_bool(daemon, true, "run as daemon (use -nodaemon for debugging)");
+
 int main(int argc, char** argv) {
   MetricsDaemon::MetricsDaemon d;
-  d.Run(false);
+  google::ParseCommandLineFlags(&argc, &argv, true);
+  d.Run(FLAGS_daemon, false);
 }