diff --git a/qinling/api/controllers/v1/execution.py b/qinling/api/controllers/v1/execution.py
index 3a535e4f..92423f36 100644
--- a/qinling/api/controllers/v1/execution.py
+++ b/qinling/api/controllers/v1/execution.py
@@ -67,7 +67,7 @@ class ExecutionsController(rest.RestController):
                 pass
 
             if func_url:
-                r = requests.post(func_url, data=params.get('input'))
+                r = requests.post(func_url, json=params.get('input'))
                 params.update(
                     {'status': 'success', 'output': {'result': r.json()}}
                 )
diff --git a/qinling/engine/default_engine.py b/qinling/engine/default_engine.py
index 36675499..2ca80a1f 100644
--- a/qinling/engine/default_engine.py
+++ b/qinling/engine/default_engine.py
@@ -79,8 +79,8 @@ class DefaultEngine(object):
                          input=None):
         LOG.info(
             'Creating execution. execution_id=%s, function_id=%s, '
-            'runtime_id=%s',
-            execution_id, function_id, runtime_id
+            'runtime_id=%s, input=%s',
+            execution_id, function_id, runtime_id, input
         )
 
         with db_api.transaction():
diff --git a/qinling/orchestrator/kubernetes/manager.py b/qinling/orchestrator/kubernetes/manager.py
index 637e210b..0496ca1b 100644
--- a/qinling/orchestrator/kubernetes/manager.py
+++ b/qinling/orchestrator/kubernetes/manager.py
@@ -298,7 +298,7 @@ class KubernetesManager(base.OrchestratorBase):
         # new connection' error for some reason. Needs to find a better
         # solution.
         time.sleep(1)
-        r = requests.post(request_url, data=data)
+        r = requests.post(request_url, json=data)
 
         if r.status_code != requests.codes.ok:
             raise exc.OrchestratorException(
@@ -355,7 +355,7 @@ class KubernetesManager(base.OrchestratorBase):
             func_url = '%s/execute' % service_url
             LOG.info('Invoke function %s, url: %s', function_id, func_url)
 
-            r = requests.post(func_url, data=input)
+            r = requests.post(func_url, json=input)
 
             return {'result': r.json()}
         else:
diff --git a/runtimes/python2/Dockerfile b/runtimes/python2/Dockerfile
index f4a8f01a..d4386aee 100644
--- a/runtimes/python2/Dockerfile
+++ b/runtimes/python2/Dockerfile
@@ -1,9 +1,9 @@
-FROM alpine:3.5
+FROM phusion/baseimage:0.9.22
+MAINTAINER lingxian.kong@gmail.com
 
-RUN apk update
-RUN apk add --no-cache linux-headers python2 python2-dev build-base py2-pip py2-pbr
-RUN pip install --upgrade pip
-RUN rm -r /root/.cache
+RUN apt-get update
+RUN apt-get -y install python-dev python-setuptools libffi-dev libxslt1-dev libxml2-dev libyaml-dev libssl-dev python-pip
+RUN pip install -U pip setuptools
 
 COPY . /app
 WORKDIR /app
diff --git a/runtimes/python2/server.py b/runtimes/python2/server.py
index fcf1d0c9..fb2cdccc 100644
--- a/runtimes/python2/server.py
+++ b/runtimes/python2/server.py
@@ -12,12 +12,13 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
+import importlib
 import json
 import logging
 import sys
 import time
+import traceback
 import zipfile
-import zipimport
 
 from flask import abort
 from flask import Flask
@@ -36,11 +37,12 @@ openstack_session = None
 
 @app.route('/download', methods=['POST'])
 def download():
-    download_url = request.form['download_url']
-    function_id = request.form['function_id']
-    entry = request.form['entry']
-    token = request.form.get('token')
-    auth_url = request.form.get('auth_url')
+    params = request.get_json() or {}
+    download_url = params.get('download_url')
+    function_id = params.get('function_id')
+    entry = params.get('entry')
+    token = params.get('token')
+    auth_url = params.get('auth_url')
 
     headers = {}
     if token:
@@ -60,14 +62,12 @@ def download():
     )
 
     r = requests.get(download_url, headers=headers, stream=True)
-
     with open(zip_file, 'wb') as fd:
         for chunk in r.iter_content(chunk_size=65535):
             fd.write(chunk)
 
     if not zipfile.is_zipfile(zip_file):
         abort(500)
-
     app.logger.info('Code package downloaded to %s' % zip_file)
 
     global function_module
@@ -85,33 +85,24 @@ def execute():
     global openstack_session
 
     context = {'os_session': openstack_session}
-
-    try:
-        importer = zipimport.zipimporter(zip_file)
-        module = importer.load_module(function_module)
-    except Exception as e:
-        return Response(
-            response=json.dumps({'output': str(e), 'duration': 0}),
-            status=200,
-            mimetype='application/json'
-        )
-
-    input = {}
-    if request.form:
-        # Refer to:
-        # http://werkzeug.pocoo.org/docs/0.12/datastructures/#werkzeug.datastructures.MultiDict
-        input = request.form.to_dict()
-
+    input = request.get_json() or {}
     app.logger.debug('Invoking function with input: %s' % input)
 
     start = time.time()
     try:
+        sys.path.insert(0, zip_file)
+        module = importlib.import_module(function_module)
         func = getattr(module, function_method)
         result = func(context=context, **input)
     except Exception as e:
         result = str(e)
-    duration = time.time() - start
 
+        # Print stacktrace
+        exc_type, exc_value, exc_traceback = sys.exc_info()
+        lines = traceback.format_exception(exc_type, exc_value, exc_traceback)
+        app.logger.debug(''.join(line for line in lines))
+
+    duration = time.time() - start
     return Response(
         response=json.dumps({'output': result, 'duration': duration}),
         status=200,