Revert of Revert "[telemetry] Wire TsProxy through telemetry's network stack."

telemetry/telemetry/internal/util/ts_proxy_server.py

Index: telemetry/telemetry/internal/util/ts_proxy_server.py
diff --git a/telemetry/telemetry/internal/util/ts_proxy_server.py b/telemetry/telemetry/internal/util/ts_proxy_server.py
index c1c761100daf22295f5f53e88b7b8991355828a7..ee72b9860d1e31a1725e3c31a869c2b669163621 100644
--- a/telemetry/telemetry/internal/util/ts_proxy_server.py
+++ b/telemetry/telemetry/internal/util/ts_proxy_server.py
@@ -37,12 +37,13 @@
   telemetry/third_party/tsproxy/tsproxy.py
   """
 
-  def __init__(self, http_port=None, https_port=None):
+  def __init__(self, host_ip=None, http_port=None, https_port=None):
     """Initialize TsProxyServer.
     """
     self._proc = None
     self._port = None
     self._is_running = False
+    self._host_ip = host_ip
     assert bool(http_port) == bool(https_port)
     self._http_port = http_port
     self._https_port = https_port
@@ -57,10 +58,11 @@
     cmd_line = [sys.executable, _TSPROXY_PATH]
     cmd_line.extend([
         '--port=0'])  # Use port 0 so tsproxy picks a random available port.
-
+    if self._host_ip:
+      cmd_line.append('--desthost=%s' % self._host_ip)
     if self._http_port:
-      cmd_line.extend([
-        '--mapports=443:%s,*:%s' % (self._https_port, self._http_port)])
+      cmd_line.append(
+        '--mapports=443:%s,*:%s' % (self._https_port, self._http_port))
     logging.info('Tsproxy commandline: %r' % cmd_line)
     self._proc = subprocess.Popen(
         cmd_line, stdout=subprocess.PIPE, stdin=subprocess.PIPE,
@@ -87,6 +89,7 @@
 
 
   def _IssueCommand(self, command_string, timeout):
+    logging.info('Issuing command to ts_proxy_server: %s', command_string)
     command_output = []
     self._proc.stdin.write('%s\n' % command_string)
     self._proc.stdin.flush()