Using a virtualenv, fixes #45 (#90)

Author: Jon Wayne Parrott

Dockerfile

@@ -6,10 +6,16 @@ COPY appengine-compat /opt/appengine-compat
 # Add the vmruntime
 COPY appengine-vmruntime /opt/appengine-vmruntime
 
+# Create a virtualenv. This virtualenv will contain the compat library,
+# vmruntime, and the user's app's dependencies.
+RUN virtualenv /env
+ENV VIRTUAL_ENV /env
+ENV PATH /env/bin:$PATH
+
 # Install the compat library and the vmruntime.
 RUN pip install --upgrade /opt/appengine-compat /opt/appengine-vmruntime
 
-# Install requirements needed by the default configuration.
+# Install the default WSGI server and dependencies.
 COPY resources/requirements.txt /opt/requirements.txt
 RUN pip install --upgrade -r /opt/requirements.txt
 
@@ -28,8 +34,8 @@ EXPOSE 8080
 # Configure the entrypoint with Managed VMs-essential configuration like "bind",
 # but leave the rest up to the config file.
 ENTRYPOINT [\
-    "/usr/bin/env",\
-    "gunicorn", "-b", ":8080",\
+    "/env/bin/gunicorn",\
+    "-b", ":8080",\
     "vmruntime.wsgi:meta_app",\
     "--log-file=-",\
     "-c", "gunicorn.conf.py"]

appengine-compat/setup.py

@@ -11,10 +11,43 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-#
+
+import os
+
 from setuptools import find_packages
 from setuptools import setup
 
+
+NAMESPACE_DECLARATION = """
+try:
+  __import__('pkg_resources').declare_namespace(__name__)
+except ImportError:
+  __path__ = __import__('pkgutil').extend_path(__path__, __name__)
+"""
+
+
+def patch_namespace_package(file):
+    with open(file, 'r') as f:
+        contents = f.read()
+
+    if NAMESPACE_DECLARATION in contents:
+        return
+
+    with open(file, 'a') as f:
+        f.write(NAMESPACE_DECLARATION)
+
+# WARNING: GIANT FLAMING LAVA PIT HACK.
+# Patch the App Engine SDK's google/__init__.py to force it to be a namespace
+# package. Without this, none of the other google namespace packages will work
+# (e.g. protobuf).
+# To be removed with github issue #91.
+patch_namespace_package(os.path.join(
+    os.path.dirname(__file__),
+    'exported_appengine_sdk',
+    'google',
+    '__init__.py'))
+
+
 setup(
     name='appengine-compat',
     version='0.64',
@@ -32,7 +65,7 @@
     package_dir={'': 'exported_appengine_sdk'},
     include_package_data=True,
     packages=find_packages('exported_appengine_sdk', exclude=['lib.*']),
-    # namespace_packages=['google'],  # This skips google/__init__.py
+    namespace_packages=['google'],
     install_requires=[
         'requests>=2.5.0',
         'webapp2>=2.5.2',