add simple plain/text http invoker support

invoker/function_invoker.py

@@ -26,6 +26,7 @@
 from shutil import copyfile
 
 import grpc_server
+import http_server
 
 
 def invoke_function(func,interaction_model, env):
@@ -36,7 +37,11 @@ def invoke_function(func,interaction_model, env):
     :param env: a dict containing the runtime environment, usually os.environ
     :return: None
     """
-    grpc_server.run(func, interaction_model, env.get("GRPC_PORT", 10382))
+
+    if env.get("GRPC_PORT") is not None:
+        grpc_server.run(func, interaction_model, env.get("GRPC_PORT", 10382))
+    else:
+        http_server.run(func=func, port=int(env.get("HTTP_PORT", 8080)))
 
 
 def install_function(env):

invoker/http_server.py

@@ -0,0 +1,12 @@
+def run(func, port):
+
+    from flask import Flask, request
+
+    app = Flask("app")
+
+    @app.route("/", methods=['POST', 'GET'])
+    def hello():
+        arg = request.data.decode("utf-8")
+        return func(arg)
+
+    app.run(port=port)

invoker/requirements.txt

@@ -1,2 +1,3 @@
 protobuf
-grpcio
+grpcio
+flask

tests/test_http_functions.py

@@ -0,0 +1,75 @@
+import sys
+
+from tests.utils import testutils
+
+import unittest
+import subprocess
+import os
+import signal
+import urllib.request
+
+sys.path.append('invoker')
+
+PYTHON = sys.executable
+
+
+class HttpFunctionTest(unittest.TestCase):
+    """
+    Spawns function_invoker in a separate process.
+    Assumes os.getcwd() is the project base directory
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        cls.workingdir = os.path.abspath("./invoker")
+        cls.command = "%s function_invoker.py" % PYTHON
+        cls.PYTHONPATH = '%s:%s' % ('%s/tests/functions:$PYTHONPATH' % os.getcwd(), '%s/invoker' % os.getcwd())
+
+    def tearDown(self):
+        os.killpg(os.getpgid(self.process.pid), signal.SIGTERM)
+
+    def test_upper(self):
+        port = testutils.find_free_port()
+
+        env = {
+            'PYTHONPATH': self.PYTHONPATH,
+            'HTTP_PORT': str(port),
+            'FUNCTION_URI': 'file://%s/tests/functions/upper.py?handler=handle' % os.getcwd()
+        }
+
+        self.process = subprocess.Popen(self.command,
+                                        cwd=self.workingdir,
+                                        shell=True,
+                                        env=env,
+                                        preexec_fn=os.setsid,
+                                        )
+
+        def generate_messages():
+            messages = [
+                ("hello", 'UTF-8'),
+                ("world", 'UTF-8'),
+                ("foo", 'UTF-8'),
+                ("bar", 'UTF-8'),
+            ]
+            for msg in messages:
+                yield msg
+
+        responses = self.call_multiple_http_messages(port, generate_messages())
+        expected = [b'HELLO', b'WORLD', b'FOO', b'BAR']
+
+        for response in responses:
+            self.assertTrue(response in expected)
+
+        self.assertEqual(len(responses), len(expected))
+
+    def call_http(self, port, message):
+        url = 'http://localhost:' + str(port)
+
+        req = urllib.request.Request(url, message.encode(), method="POST", headers={"content-type": "text/plain"})
+        response = urllib.request.urlopen(req)
+        return response.read()
+
+    def call_multiple_http_messages(self, port, messages):
+        import time
+        time.sleep(1)
+        return [self.call_http(port, message[0]) for message in messages]