Create a transparent proxy for test programs to use, with the

bin/cros_au_test_harness.py

Index: bin/cros_au_test_harness.py
diff --git a/bin/cros_au_test_harness.py b/bin/cros_au_test_harness.py
index 4cb6653d17a65a800c7b57008ed926071a5eab95..0e484947ab26cf6204f36cbe5cced81c32b39c52 100755
--- a/bin/cros_au_test_harness.py
+++ b/bin/cros_au_test_harness.py
@@ -8,6 +8,8 @@ import optparse
 import os
 import re
 import sys
+import thread
+import time
 import unittest
 import urllib
 
@@ -19,6 +21,8 @@ from cros_build_lib import RunCommand
 from cros_build_lib import RunCommandCaptureOutput
 from cros_build_lib import Warning
 
+import cros_test_proxy
+
 # VM Constants.
 _FULL_VDISK_SIZE = 6072
 _FULL_STATEFULFS_SIZE = 3074
@@ -90,20 +94,21 @@ class AUTest(object):
     else:
       self._UpdateImageReportError(image)
 
-  def _UpdateImageReportError(self, image_path, stateful_change='old'):
+  def _UpdateImageReportError(self, image_path, stateful_change='old',
+                              proxy_port=None):
     """Calls UpdateImage and reports any error to the console.
 
        Still throws the exception.
     """
     try:
-      self.UpdateImage(image_path, stateful_change)
+      self.UpdateImage(image_path, stateful_change, proxy_port)
     except UpdateException as err:
       # If the update fails, print it out
       Warning(err.stdout)
       raise
 
   def _AttemptUpdateWithPayloadExpectedFailure(self, payload, expected_msg):
-    # This update is expected to fail...
+    """Attempt a payload update, expect it to fail with expected log"""
     try:
       self.UpdateUsingPayload(payload)
     except UpdateException as err:
@@ -115,11 +120,32 @@ class AUTest(object):
     Warning(err.stdout)
     self.fail('We managed to update when failure was expected')
 
+  def _AttemptUpdateWithFilter(self, filter):
+    """Update through a proxy, with a specified filter, and expect success."""
+
+    self.PrepareBase(target_image_path)
+
+    # The devserver runs at port 8080 by default. We assume that here, and  
+    # start our proxy at 8081. We then tell our update tools to have the    
+    # client connect to 8081 instead of 8080.
+    proxy_port = 8081
+    proxy = cros_test_proxy.CrosTestProxy(port_in=proxy_port,
+                                          address_out='127.0.0.1',
+                                          port_out=8080,
+                                          filter=filter)
+    proxy.serve_forever_in_thread()
+
+    # This update is expected to fail...
+    try:
+      self._UpdateImageReportError(target_image_path, proxy_port=proxy_port)
+    finally:
+      proxy.shutdown()
+
   def PrepareBase(self, image_path):
     """Prepares target with base_image_path."""
     pass
 
-  def UpdateImage(self, image_path, stateful_change='old'):
+  def UpdateImage(self, image_path, stateful_change='old', proxy_port=None):
     """Updates target with the image given by the image_path.
 
     Args:
@@ -129,15 +155,22 @@ class AUTest(object):
           'old':  Don't modify stateful partition.  Just update normally.
           'clean':  Uses clobber-state to wipe the stateful partition with the
             exception of code needed for ssh.
+      proxy_port:  Port to have the client connect to. For use with
+        CrosTestProxy.
     """
     pass
 
-  def UpdateUsingPayload(self, update_path, stateful_change='old'):
+  def UpdateUsingPayload(self,
+                         update_path,
+                         stateful_change='old',
+                         proxy_port=None):
     """Updates target with the pre-generated update stored in update_path
 
     Args:
       update_path:  Path to the image to update with. This directory should
-      contain both update.gz, and stateful.image.gz
+        contain both update.gz, and stateful.image.gz
+      proxy_port:  Port to have the client connect to. For use with
+        CrosTestProxy.
     """
     pass
 
@@ -187,7 +220,7 @@ class AUTest(object):
     """
     # Just make sure some tests pass on original image.  Some old images
     # don't pass many tests.
-    self.PrepareBase(image_path=base_image_path)
+    self.PrepareBase(base_image_path)
     # TODO(sosa): move to 100% once we start testing using the autotest paired
     # with the dev channel.
     percent_passed = self.VerifyImage(10)
@@ -210,7 +243,7 @@ class AUTest(object):
     """
     # Just make sure some tests pass on original image.  Some old images
     # don't pass many tests.
-    self.PrepareBase(image_path=base_image_path)
+    self.PrepareBase(base_image_path)
     # TODO(sosa): move to 100% once we start testing using the autotest paired
     # with the dev channel.
     percent_passed = self.VerifyImage(10)
@@ -228,7 +261,7 @@ class AUTest(object):
   def testPartialUpdate(self):
     """Tests what happens if we attempt to update with a truncated payload."""
     # Preload with the version we are trying to test.
-    self.PrepareBase(image_path=target_image_path)
+    self.PrepareBase(target_image_path)
 
     # Image can be updated at:
     # ~chrome-eng/chromeos/localmirror/autest-images
@@ -245,7 +278,7 @@ class AUTest(object):
   def testCorruptedUpdate(self):
     """Tests what happens if we attempt to update with a corrupted payload."""
     # Preload with the version we are trying to test.
-    self.PrepareBase(image_path=target_image_path)
+    self.PrepareBase(target_image_path)
 
     # Image can be updated at:
     # ~chrome-eng/chromeos/localmirror/autest-images
@@ -260,6 +293,71 @@ class AUTest(object):
     expected_msg = 'zlib inflate() error:-3'
     self._AttemptUpdateWithPayloadExpectedFailure(payload, expected_msg)
 
+  def testInterruptedUpdate(self):
+    """Tests what happens if we interrupt payload delivery 3 times."""
+
+    class InterruptionFilter(cros_test_proxy.Filter):
+      """This filter causes the proxy to interrupt the download 3 times
+      
+         It does this by closing the first three connections to transfer
+         2M total in the outbound connection after they transfer the 
+         2M.
+      """
+      def __init__(self):
+        """Defines variable shared across all connections"""
+        self.close_count = 0
+      
+      def setup(self):
+        """Called once at the start of each connection."""
+        self.data_size = 0
+
+      def OutBound(self, data):
+        """Called once per packet for outgoing data.
+
+           The first three connections transferring more than 2M
+           outbound will be closed.
+        """
+        if self.close_count < 3:
+          if self.data_size > (2 * 1024 * 1024):
+            self.close_count += 1
+            return None
+        
+        self.data_size += len(data)
+        return data 
+
+    self._AttemptUpdateWithFilter(InterruptionFilter())
+
+  def testDelayedUpdate(self):
+    """Tests what happens if some data is delayed during update delivery"""
+
+    class DelayedFilter(cros_test_proxy.Filter):
+      """Causes intermittent delays in data transmission.
+      
+         It does this by inserting 3 20 second delays when transmitting
+         data after 2M has been sent.
+      """
+      def setup(self):
+        """Called once at the start of each connection."""
+        self.data_size = 0
+        self.delay_count = 0
+
+      def OutBound(self, data):
+        """Called once per packet for outgoing data.
+
+           The first three packets after we reach 2M transferred
+           are delayed by 20 seconds.
+        """
+        if self.delay_count < 3:
+          if self.data_size > (2 * 1024 * 1024):
+            self.delay_count += 1
+            time.sleep(20)
+        
+        self.data_size += len(data)
+        return data 
+
+
+    self._AttemptUpdateWithFilter(DelayedFilter())
+
 class RealAUTest(unittest.TestCase, AUTest):
   """Test harness for updating real images."""
 
@@ -270,7 +368,7 @@ class RealAUTest(unittest.TestCase, AUTest):
     """Auto-update to base image to prepare for test."""
     self._UpdateImageReportError(image_path)
 
-  def UpdateImage(self, image_path, stateful_change='old'):
+  def UpdateImage(self, image_path, stateful_change='old', proxy_port=None):
     """Updates a remote image using image_to_live.sh."""
     stateful_change_flag = self.GetStatefulChangeFlag(stateful_change)
     cmd = ['%s/image_to_live.sh' % self.crosutils,
@@ -281,6 +379,9 @@ class RealAUTest(unittest.TestCase, AUTest):
            '--src_image=%s' % self.source_image
           ]
 
+    if proxy_port:
+      cmd.append('--proxy_port=%s' % proxy_port) 
+
     if self.verbose:
       try:
         RunCommand(cmd)
@@ -291,7 +392,10 @@ class RealAUTest(unittest.TestCase, AUTest):
       if code != 0:
         raise UpdateException(code, stdout)
 
-  def UpdateUsingPayload(self, update_path, stateful_change='old'):
+  def UpdateUsingPayload(self,
+                         update_path,
+                         stateful_change='old',
+                         proxy_port=None):
     """Updates a remote image using image_to_live.sh."""
     stateful_change_flag = self.GetStatefulChangeFlag(stateful_change)
     cmd = ['%s/image_to_live.sh' % self.crosutils,
@@ -301,6 +405,9 @@ class RealAUTest(unittest.TestCase, AUTest):
            '--verify',
           ]
 
+    if proxy_port:
+      cmd.append('--proxy_port=%s' % proxy_port) 
+
     if self.verbose:
       try:
         RunCommand(cmd)
@@ -366,7 +473,7 @@ class VirtualAUTest(unittest.TestCase, AUTest):
 
     self.assertTrue(os.path.exists(self.vm_image_path))
 
-  def UpdateImage(self, image_path, stateful_change='old'):
+  def UpdateImage(self, image_path, stateful_change='old', proxy_port=None):
     """Updates VM image with image_path."""
     stateful_change_flag = self.GetStatefulChangeFlag(stateful_change)
     if self.source_image == base_image_path:
@@ -382,6 +489,10 @@ class VirtualAUTest(unittest.TestCase, AUTest):
            stateful_change_flag,
            '--src_image=%s' % self.source_image,
            ]
+
+    if proxy_port:
+      cmd.append('--proxy_port=%s' % proxy_port) 
+
     if self.verbose:
       try:
         RunCommand(cmd)
@@ -392,7 +503,10 @@ class VirtualAUTest(unittest.TestCase, AUTest):
       if code != 0:
         raise UpdateException(code, stdout)
 
-  def UpdateUsingPayload(self, update_path, stateful_change='old'):
+  def UpdateUsingPayload(self,
+                         update_path,
+                         stateful_change='old',
+                         proxy_port=None):
     """Updates a remote image using image_to_live.sh."""
     stateful_change_flag = self.GetStatefulChangeFlag(stateful_change)
     if self.source_image == base_image_path:
@@ -409,6 +523,9 @@ class VirtualAUTest(unittest.TestCase, AUTest):
            '--src_image=%s' % self.source_image,
            ]
 
+    if proxy_port:
+      cmd.append('--proxy_port=%s' % proxy_port) 
+
     if self.verbose:
       try:
         RunCommand(cmd)
@@ -502,6 +619,8 @@ if __name__ == '__main__':
   elif options.type == 'real': test_class = RealAUTest
   else: parser.error('Could not parse harness type %s.' % options.type)
 
+  remote = options.remote
+
   test_suite = test_loader.loadTestsFromTestCase(test_class)
   test_result = unittest.TextTestRunner(verbosity=2).run(test_suite)