I have a thorny problem that I can't seem to get to grips with. I am
currently writing unit tests for a django custom auth-backend. On our
system we actually have two backends: one the built-in django backend
and the custom backend that sends out requests to a Java based API
that returns user info in the form of XML. Now, I am writing unit
tests so I don't want to be sending requests outside the system like
that, I'm not trying to test the Java API, so my question is how can I
get around this and mock the side-effects in the most robust way.
The function I am testing is something like this, where the url
settings value is just the base url for the Java server that
authenticates the username and password data and returns the xml, and the service value is
just some magic for building the url query, its unimportant for
us:
#staticmethod
def get_info_from_api_with_un_pw(username, password, service=12345):
url = settings.AUTHENTICATE_URL_VIA_PASSWORD
if AUTH_FIELD == "username":
params = {"nick": username, "password": password}
elif AUTH_FIELD == "email":
params = {"email": username, "password": password}
params["service"] = service
encoded_params = urlencode([(k, smart_str(v, "latin1")) for k, v in params.items()])
try:
# get the user's data from the api
xml = urlopen(url + encoded_params).read()
userinfo = dict((e.tag, smart_unicode(e.text, strings_only=True))
for e in ET.fromstring(xml).getchildren())
if "nil" in userinfo:
return userinfo
else:
return None
So, we get the xml, parse it into a dict and if the key nil is present
then we can return the dict and carry on happy and authenticated.
Clearly, one solution is just to find a way to somehow override or
monkeypatch the logic in the xml variable, I found this answer:
How can one mock/stub python module like urllib
I tried to implement something like that, but the details there are
very sketchy and I couldn't seem to get that working.
I also captured the xml response and put it in a local file in the
test folder with the intention of finding a way to use that as a mock
response that is passed into the url parameter of the test function,
something like this will override the url:
#override_settings(AUTHENTICATE_URL_VIA_PASSWORD=(os.path.join(os.path.dirname(__file__), "{0}".format("response.xml"))))
def test_get_user_info_username(self):
self.backend = RemoteAuthBackend()
self.backend.get_info_from_api_with_un_pw("user", "pass")
But that also needs to take account of the url building logic that the
function defines, (i.e. "url + encoded_params"). Again, I could rename
the response file to be the same as the concatenated url but this is becoming
less like a good unit-test for the function and more of a "cheat", the whole
thing is just getting more and more brittle all the time with these solutions, and its really just a fixture anyway, which is also something I want to avoid if
at all possible.
I also wondered if there might be a way to serve the xml on the django development server and then point the function at that? It seems like a saner solution, but much googling gave me no clues if such a thing would be possible or advisable and even then I don't think that would be a test to run outside of the development environment.
So, ideally, I need to be able to somehow mock a "server" to
take the place of the Java API in the function call, or somehow serve
up some xml payload that the function can open as its url, or
monkeypatch the function from the test itself, or...
Does the mock library have the appropriate tools to do such things?
http://www.voidspace.org.uk/python/mock
So, there are two points to this question 1) I would like to solve my
particular problem in a clean way, and more importantly 2) what are
the best practices for cleanly writing Django unit-tests when you are
dependent on data, cookies, etc. for user authentication from a remote
API that is outside of your domain?
The mock library should work if used properly. I prefer the minimock library and I wrote a small base unit testcase (minimocktest) that helps with this.
If you want to integrate this testcase with Django to test urllib you can do it as follows:
from minimocktest import MockTestCase
from django.test import TestCase
from django.test.client import Client
class DjangoTestCase(TestCase, MockTestCase):
'''
A TestCase class that combines minimocktest and django.test.TestCase
'''
def _pre_setup(self):
MockTestCase.setUp(self)
TestCase._pre_setup(self)
# optional: shortcut client handle for quick testing
self.client = Client()
def _post_teardown(self):
TestCase._post_teardown(self)
MockTestCase.tearDown(self)
Now you can use this testcase instead of using the Django test case directly:
class MySimpleTestCase(DjangoTestCase):
def setUp(self):
self.file = StringIO.StringIO('MiniMockTest')
self.file.close = self.Mock('file_close_function')
def test_urldump_dumpsContentProperly(self):
self.mock('urllib2.urlopen', returns=self.file)
self.assertEquals(urldump('http://pykler.github.com'), 'MiniMockTest')
self.assertSameTrace('\n'.join([
"Called urllib2.urlopen('http://pykler.github.com')",
"Called file_close_function()",
]))
urllib2.urlopen('anything')
self.mock('urllib2.urlopen', returns=self.file, tracker=None)
urllib2.urlopen('this is not tracked')
self.assertTrace("Called urllib2.urlopen('anything')")
self.assertTrace("Called urllib2.urlopen('this is mocked but not tracked')", includes=False)
self.assertSameTrace('\n'.join([
"Called urllib2.urlopen('http://pykler.github.com')",
"Called file_close_function()",
"Called urllib2.urlopen('anything')",
]))
Here's the basics of the solution that I ended up with for the record. I used the Mock library itself rather than Mockito in the end, but the idea is the same:
from mock import patch
#override_settings(AUTHENTICATE_LOGIN_FIELD="username")
#patch("mymodule.auth_backend.urlopen")
def test_get_user_info_username(self, urlopen_override):
response = "file://" + os.path.join(os.path.dirname(__file__), "{0}".format("response.xml"))
# mock patch replaces API call
urlopen_override.return_value = urlopen(response)
# call the patched object
userinfo = RemoteAuthBackend.get_info_from_api_with_un_pw("user", "pass")
assert_equal(type(userinfo), dict)
assert_equal(userinfo["nick"], "user")
assert_equal(userinfo["pass"], "pass")
Related
I have configured a dependencies.py where I'm injecting a set of dependencies to different services by using python's binder.bind(my_config). The goal is being able to easily inject those services to each endpoint of my API. The problem arises when I pass that service as an argument to my endpoint , after having injected that service via its name. So:
import inject
from fastapi import APIRouter, HTTPException, Request, Depends
from src.services.chords import ChordsService
router = APIRouter(prefix="/chords")
#router.get("")
#inject.params(chords_service=ChordsService)
def get_chords(chords_service: ChordsService, req: Request, key: str, suffix: str = None, instrument: str = None):
params = dict(req.query_params)
return chords_service.get(params)
This does not work. I've tried changing the order of get_chords' arguments. All I'm getting is different errors, but the one that appears the most is the following:
ChordsService is not a valid pydantic field type
I've read a bit about the use of pydantic in FastAPI and I see why I get this error, but I'm stuck at trying to inject those services. Is there a way to do it? Thanks!
You could use the dependency injection from fastapi directly. I don't have an IDE, so syntax is probably wrong, but you could do something like:
#lru_cache(max_size=1)
def get_chords_service():
return ChordsService()
#router.get("")
def get_chords(chords_service: ChordsService=Depends(get_chords_service), req: Request ...
This if you want the same ChordService instance everywhere.
If you are ok getting a new one each time, it becomes much simpler (you don't even need the getter function):
#router.get("")
def get_chords(chords_service: ChordsService=Depends(), req: Request ...
You can inject dependency to APIRouter like below -
router = APIRouter(prefix="/chords",
dependencies=[Depends(ChordsService)])
See Example: https://fastapi.tiangolo.com/tutorial/bigger-applications/#another-module-with-apirouter
I have some experience with different web frameworks (Django, web.py, Pyramid and CherryPy), and I'm wondering in which one will it be easier and hopefully cleaner to implement a route dispatcher to a different "view/handler" based on the "Accept" header and the HTTP method e.g.:
Accept: application/json
POST /post/
is handled different than:
Accept: text/html
POST /post/
So the request gets routed to the particular view of the corresponding handler of the MIME "application/json" and the HTTP method "POST".
I do know how to implement something like that in CherryPy, but I lose the use of the CherryPy tools for the internal redirection of the request because I'm calling the specific method directly instead of automagically from the dispatcher. Another option is to implement a full new dispatcher from scratch, but that's the last option.
I'm aware of the alternative to use extensions in the url like /post.json or /post/.json, but I'm looking to keep the same url?
If all you are looking for is one framework that can do this easily, then use pyramid.
Pyramid view definitions are made with predicates, not just routes, and a view only matches if all predicates match. One such predicate is the accept predicate, which does exactly what you want; make view switching depending on the Accept header easy and simple:
from pyramid.view import view_config
#view_config(route_name='some_api_name', request_method='POST', accept='application/json')
def handle_someapi_json(request):
# return JSON
#view_config(route_name='some_api_name', request_method='POST', accept='text/html')
def handle_someapi_html(request):
# return HTML
I needed to do this in Django, and so I wrote a piece of middleware to make it possible: http://baltaks.com/2013/01/route-requests-based-on-the-http-accept-header-in-django
Here is the code:
# A simple middleware component that lets you use a single Django
# instance to serve multiple versions of your app, chosen by the client
# using the HTTP Accept header.
# In your settings.py, map a value you're looking for in the Accept header
# to a urls.py file.
# HTTP_HEADER_ROUTING_MIDDLEWARE_URLCONF_MAP = {
# u'application/vnd.api-name.v1': 'app.urls_v1'
# }
from django.conf import settings
class HTTPHeaderRoutingMiddleware:
def process_request(self, request):
try:
for content_type in settings.HTTP_HEADER_ROUTING_MIDDLEWARE_URLCONF_MAP:
if (request.META['HTTP_ACCEPT'].find(content_type) != -1):
request.urlconf = settings.HTTP_HEADER_ROUTING_MIDDLEWARE_URLCONF_MAP[content_type]
except KeyError:
pass # use default urlconf (settings.ROOT_URLCONF)
def process_response(self, request, response):
return response
I'm not suite sure what you mean by "internal redirection", but if you look at the code you can see that tools.accept is a really thin wrapper around lib.cptools.accept, which you can call from your own code easily. Hand it a list of Content-Types your server can send, and it will tell you which one the client prefers, or raise 406 if the types you emit and the types the client accepts don't overlap.
The problem is simple, we would like CherryPy to not log access log for a particular exposed method/API that gets called.
Basically when this API gets called, there are some parameters in the query string of the URL which are very sensitive and if leaked, would expose potential security. Naturally this is a /GET request and unfortunately it is the only way the parameters could be passed, since its a redirect(302) from an external service to this web server.
If it would not log the URL, that would serve the purpose as well.
So, is there a way that we can filter logging messages in access log by API's, URL's etc?
Thanks in advance for the help.
cherrypy uses Python's standard logging module by default, so you can just add a custom filter. This example will ignore any GET request with /foo as the path prefix:
import logging
class IgnoreURLFilter(logging.Filter):
# simple example of log message filtering
def __init__(self, ignore):
self.ignore = 'GET /' + ignore
def filter(self, record):
return self.ignore not in record.getMessage()
app = cherrypy.tree.mount( YourApplication() )
app.log.access_log.addFilter( IgnoreURLFilter('foo') )
cherrypy.engine.start()
We are writing a client for a remote service that exposes SOAP web services and publishes a WSDL definition for those services.
We don't have access to the system during testing, so we'd like to write a mock service. We're using Python for the client, so ideally we'd want to use Python for the mock server, although I suppose it's not strictly necessary.
The dream would be to be able to generate stubs from the WSDL file which we could fill in, and then serve those using Paste Deploy as a WSGI server, although it doesn't have to be Paste Deploy or WSGI so long as it works reliably. The main thing is that we need to be generating the stubs from the "real" WSDL file so that we don't accidentally write a non-compliant mock server.
We're using suds for the client side library, and have looked at soaplib and ZSI. However, the wsgi2py stuff in soaplib says "do not use" at the top and ZSI seems like a lot to swallow. What do people generally use for this kind of thing?
Martin
As a mock server I would really recommend soapUI (http://www.soapui.org).
It takes a WSDL and generates the services and service methods automatically. You can then go on and define static returns or dynamic ones using Groovy scripts. Take a look here for the documentation of web service mocking.
soapUI comes in a free and paid pro version. I have used the free version with great success.
I would recommend you use soapUI for creating a mock service. It's very easy to install. It's just as easy to create a WS mock service.
It takes the WSDL file from your desired location, it creates the structure for the requests and if you wish, it also creates the mock web service with the intended structure drawn from the WSDL file.
When you create the new soapUI project, select the third checkbox option to create the mock web service.
If xsd schema files are required, make sure they are well referenced from the WSDL file.
It doesn't use python but if all you need is a test environment that you can send requests and get responses, that will be more than enough.
I hope that helps.
You could use this code for creating a suds mock client.
from suds.client import Client
class AlwaysCallable(object):
"""
Represents a chainable-access object and proxies calls to ClientMock.
"""
name = None
def __init__(self, client_cls):
self._client_cls = client_cls
def __call__(self, *args, **kwargs):
try:
hook = object.__getattribute__(self._client_cls, self.name)
except AttributeError:
pass
else:
return hook(self._client_cls, *args, **kwargs)
def __getattr__(self, item):
new = object.__getattribute__(self, '__class__')(self._client_cls)
new.name = item
return new
class ClientMock(Client):
"""
Abstract mock suds client.
"""
def __init__(self, url, **kwargs):
pass
def __getattr__(self, item):
return AlwaysCallable(self.__class__)
def __unicode__(self):
return 'Client mock'
def __str__(self):
return 'Client mock'
And next define a concrete ClientMock.
class UserCredentialsServiceClientMock(ClientMock):
"""
Mock object that implements remote side services.
"""
def GetUserInfo(cls, user_id):
"""
Stub for remote service.
"""
return UserInfo(id=user_id, name='Adam Smith')
Now you could use mock library to spoof a code, that uses suds.client.Client.
from unittest import TestCase
from mock import patch
from project.api import get_user_credentials
class UserCredentialsClientTestCase(TestCase):
def test_getting_user_credentials(self):
with patch('project.api.Client', new=UserCredentialsServiceClientMock):
self.assertEquals(get_user_credentials(1), 'Adam Smith')
Is there any example code of a cpython (not IronPython) client which can call Windows Communication Foundation (WCF) service?
I used suds.
from suds.client import Client
print "Connecting to Service..."
wsdl = "http://serviceurl.com/service.svc?WSDL"
client = Client(wsdl)
result = client.service.Method(variable1, variable2)
print result
That should get you started. I'm able to connect to exposed services from WCF and a RESTful layer. There needs to be some data massaging to help do what you need, especially if you need to bind to several namespaces.
TL;DR: For wsHttpBinding (SOAP 1.2) use zeep
In case someone is having trouble using suds (or suds-jurko for that matter) with WCF and wsHttpBinding (which is SOAP 1.2):
suds is pretty much dead (can't even pip install it on python 3)
suds-jurko seems kind-of dead. The 0.6 release has a very annoying infinite recursion bug (at least on the WSDL exposed by our service) which is fixed in the tip but that's not released and it's been 1.5years (at time of this writing in Feb'17) since the last commit.
It works on python 3 but doesn't support SOAP 1.2. Sovetnikov's answer is an attempt to get it working with 1.2 but I haven't managed to make it work for me.
zeep seems to be the current way to go and worked out of the box (I'm not affiliated with zeep, it just works for me and I spent several hours banging my head against a brick wall trying to make suds work). For zeep to work, the WCF service host configuration must include <security mode="None"/> under the wsHttpBinding node Actually zeep seems to support username and signature (x509) based WS-SE but I haven't tried that so can't speak to any problems around it.
WCF needs to expose functionality through a communication protocol. I think the most commonly used protocol is probably SOAP over HTTP. Let's assume that's
what you're using then.
Take a look at this chapter in Dive Into Python. It will show you how to
make SOAP calls.
I know of no unified way of calling a WCF service in Python, regardless of communication
protocol.
Just to help someone to access WCF SOAP 1.2 service with WS-Addressing using suds.
Main problem is to inject action name in every message.
This example for python 3 and suds port https://bitbucket.org/jurko/suds.
Example uses custom authentification based on HTTP headers, i leave it as is.
TODO: Automatically get api_direct_url from WSDL (at now it is hard coded).
from suds.plugin import MessagePlugin
from suds.sax.text import Text
from suds.wsse import Security, UsernameToken
from suds.sax.element import Element
from suds.sax.attribute import Attribute
from suds.xsd.sxbasic import Import
api_username = 'some'
api_password = 'none'
class api(object):
api_direct_url = 'some/mex'
api_url = 'some.svc?singleWsdl|Wsdl'
NS_WSA = ('wsa', 'http://www.w3.org/2005/08/addressing')
_client_instance = None
#property
def client(self):
if self._client_instance:
return self._client_instance
from suds.bindings import binding
binding.envns = ('SOAP-ENV', 'http://www.w3.org/2003/05/soap-envelope')
api_inst = self
class _WSAPlugin(MessagePlugin):
def marshalled(self, context):
api_inst._marshalled_message(context)
self._client_instance = Client(self.api_url,
plugins=[_WSAPlugin()],
headers={'Content-Type': 'application/soap+xml',
'login':api_username,
'password': api_password}
)
headers = []
headers.append(Element('To', ns=self.NS_WSA).setText(self.api_direct_url))
headers.append(Element('Action', ns=self.NS_WSA).setText('Blank'))
self._client_instance.set_options(soapheaders=headers)
cache = self._client_instance.options.cache
cache.setduration(days=10)
return self._client_instance
def _marshalled_message(self, context):
def _children(r):
if hasattr(r, 'children'):
for c in r.children:
yield from _children(c)
yield c
for el in _children(context.envelope):
if el.name == 'Action':
el.text = Text(self._current_action)
return
_current_action = None
def _invoke(self, method, *args):
try:
self._current_action = method.method.soap.action.strip('"')
return method(*args)
finally:
self._current_action = None
def GetRequestTypes(self):
return self._invoke(self.client.service.GetRequestTypes)[0]
def GetTemplateByRequestType(self, request_type_id):
js = self._invoke(self.client.service.GetTemplateByRequestType, request_type_id)
return json.loads(js)
def GetRequestStatus(self, request_guid):
return self._invoke(self.client.service.GetRequestStatus, request_guid)
def SendRequest(self, request_type_id, request_json):
r = json.dumps(request_json, ensure_ascii=False)
return self._invoke(self.client.service.SendRequest, request_type_id, r)
I do not know of any direct examples, but if the WCF service is REST enabled you could access it through POX (Plain Old XML) via the REST methods/etc (if the service has any). If you are in control of the service you could expose endpoints via REST as well.
if you need binary serialized communication over tcp then consider implementing solution like Thrift.
Even if there is not a specific example of calling WCF from Python, you should be able to make a fully SOAP compliant service with WCF. Then all you have to do is find some examples of how to call a normal SOAP service from Python.
The simplest thing will be to use the BasicHttpBinding in WCF and then you can support your own sessions by passing a session token with each request and response.