Improved handling of missing files.

lwr/framework.py

@@ -7,6 +7,7 @@ from webob import Response
 from webob import exc
 
 import inspect
+from os.path import exists
 import re
 
 from simplejson import dumps
@@ -94,7 +95,11 @@ class Controller(object):
                 resp = Response(body=dumps(result))
             elif self.response_type == 'file':
                 resp = Response()
-                resp.app_iter = FileIterator(result)
+                path = result
+                if exists(path):
+                    resp.app_iter = FileIterator(path)
+                else:
+                    raise exc.HTTPNotFound("No file found with path %s." % path)
             else:
                 resp = Response(body='OK')
             return resp(environ, start_response)

lwr/lwr_client/client.py

@@ -19,6 +19,15 @@ class parseJson(object):
         return replacement
 
 
+class OutputNotFoundException(Exception):
+
+    def __init__(self, path):
+        self.path = path
+
+    def __str__(self):
+        return "No remote output found for path %s" % self.path
+
+
 class Client(object):
     """
     Objects of this client class perform low-level communication with a remote LWR server.
@@ -163,7 +172,7 @@ class Client(object):
         elif output_type == "task":
             output_path = os.path.join(working_directory, name)
         else:
-            raise Exception("No remote output found for dataset with path %s" % path)
+            raise OutputNotFoundException("No remote output found for dataset with path %s" % path)
         self.__raw_download_output(name, self.job_id, output_type, output_path)
 
     def __raw_download_output(self, name, job_id, output_type, output_path):

run_client_tests.py

@@ -21,6 +21,7 @@ def main():
     parser = optparse.OptionParser()
     parser.add_option('--url', dest='url', default='http://localhost:8913/')
     parser.add_option('--private_token', default=None)
+    parser.add_option('--test_errors', default=False, action="store_true")
     (options, args) = parser.parse_args()
 
     try:
@@ -70,6 +71,11 @@ finally:
         client.launch(new_command)
         client.wait()
         client.download_output(temp_output_path, temp_directory)
+        if options.test_errors:
+            try:
+                client.download_output(temp_output_path + "x", temp_directory)
+            except BaseException, e:
+                traceback.print_exc(e)
         output_file = open(temp_output_path, 'r')
         try:
             output_contents = output_file.read()

test/app_test.py

@@ -46,6 +46,12 @@ def test_app():
         download_response = test_app.get("/download_output?job_id=%s&name=test_output" % job_id)
         assert download_response.body == "Hello World!"
 
+        try:
+            test_app.get("/download_output?job_id=%s&name=test_output2" % job_id)
+            assert False  # Should throw exception
+        except:
+            pass
+
         command_line = urllib.quote("""python -c "import sys; sys.stdout.write('test_out')" """)
         launch_response = test_app.get("/launch?job_id=%s&command_line=%s" % (job_id, command_line))
         assert launch_response.body == 'OK'