Created question in FIWARE Q/A platform on 11-05-2016 at 15:05
Please, ANSWER this question AT https://stackoverflow.com/questions/37164185/wirecloud-and-horizon-behind-https-proxy

Question:
WireCloud and Horizon behind HTTPS proxy

Description:
We have a proxy running that serves HTTPS pages to the internet. Therefore it redirects requests into our DMZ where the pages are served as HTTP pages.

We got WireCloud set up to run at a subdomain: wirecloud.example.com. Horizon runs at horizon.example.com.

In Horizon the Callback URL is set to: http://wirecloud.example.com/complete/fiware/ and in the settings.py of Wirecloud the FIWARE_IDM_SERVER = 'http://horizon.example.com' is set.

Now, when wirecloud.example.com/login gets called, it is redirected to https by our proxy and then redirected to horizon by wireclound what then gets redirected by our proxy to https://horizon.example.com/oauth2/authorize/?state=STATE_KEY&redirect_uri=http://wirecloud.example.com/complete/fiware/&response_type=code&client_id=CLIENT_ID. If the user is not logged in and now does so the redirect_uri gets transformed to this: http%253A%252F%252Fwirecloud.example.com%252Fcomplete%252Ffiware%252F what leads to this error:

(HTTP 400). If the user is already logged in and tries to authorize the app (WireCloud) a 405 error gets thrown:

Environment:

Request Method: GET
Request URL: http://wirecloud.example.com/complete/fiware/?state=STATE_KEY&code=CODE

Django Version: 1.9.6
Python Version: 2.7.9
Installed Applications:
('django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'django.contrib.admin',
'wirecloud.commons',
'compressor',
'wirecloud.catalogue',
'wirecloud.platform',
'wirecloud.oauth2provider',
'wirecloud.fiware',
'social.apps.django_app.default')
Installed Middleware:
('wirecloud.commons.middleware.URLMiddleware',)

Traceback:

File "/opt/wc/venv/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
149. response = self.process_exception_by_middleware(e, request)

File "/opt/wc/venv/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
147. response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/django/views/decorators/cache.py" in _wrapped_view_func
57. response = view_func(request, *args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/django/views/decorators/csrf.py" in wrapped_view
58. return view_func(*args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/apps/django_app/utils.py" in wrapper
51. return func(request, backend, *args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/apps/django_app/views.py" in complete
28. redirect_name=REDIRECT_FIELD_NAME, *args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/actions.py" in do_complete
43. user = backend.complete(user=user, *args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/backends/base.py" in complete
41. return self.auth_complete(*args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/utils.py" in wrapper
229. return func(*args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/backends/oauth.py" in auth_complete
383. method=self.ACCESS_TOKEN_METHOD

File "/opt/wc/venv/lib/python2.7/site-packages/social/backends/oauth.py" in request_access_token
361. return self.get_json(*args, **kwargs)

File "/opt/wc/venv/lib/python2.7/site-packages/social/backends/base.py" in get_json
229. return self.request(url, *args, **kwargs).json()

File "/opt/wc/venv/lib/python2.7/site-packages/social/backends/base.py" in request
225. response.raise_for_status()

File "/opt/wc/venv/lib/python2.7/site-packages/requests/models.py" in raise_for_status
844. raise HTTPError(http_error_msg, response=self)

Exception Type: HTTPError at /complete/fiware/
Exception Value: 405 Client Error: METHOD NOT ALLOWED for url: https://horizon.example.com/oauth2/token

So how do we need to configure WireCloud and/or Horizon and/or our proxy to get this to work?