I'm quite new in Python world. I come from java and ABAP world, where their application server are able to handle stateful request.
Is it also possible in python using WSGI?
Or stateful and stateless are handled in other layer?
Usually, you don't work with "bare" WSGI. You work with web-frameworks, such as Pylons or TurboGears2.
And these contain a session-middleware, based on WSGI - called "Beaker". But if you work with the framework, you don't have to worry about that - you just use it.
But if you insist, you can of course use Beaker standalone.
I prefer working directly on wsgi, along with mako and psycopg.
It's good to know about Beaker, though I usually don't hold state in the server because I believe it reduces scalability. I either put it in the user's cookie, in the database tied to a token in the user's cookie, or in a redirect url.
Your question is a little vague and open-ended. First of all, WSGI itself isn't a framework, it's just the glue to connect a framework to the web server. Secondly, I'm not clear on what you mean when you say "state" -- do you mean storing information about a client on the server? If so, web frameworks (Pylons, Django, etc) allow you to store that kind of information in web session variables.
Related
I'm trying to figure out how to build a TCP proxy on GAE (Google App Engine). I would ordinarily do it using twisted networking engine but GAE doesn't allow frameworks. I'm also pretty new to internet and networking technologies in general.
Basically I have a proxy server and I'd like to use GAE as a TCP proxy to relay everything to the primary proxy server. All the GAE front ends are connected to the back end by google fiber, so if I make the back end near the primary proxy server, it should make it super fast regardless of where I'm connecting from.
Unfortunately GAE doesn't allow me to control ports at all and everything that I'm reading either tells me how to configure a TCP proxy on a server that I'm in complete control of or how to configure a proxy where I type the url into a webpage in the browser. Something along the lines of making a personal http://www.hidemyass.com/proxy/ type of website.
I'd like to set it up so I can simply tell chrome to ignore certificate errors (it connects to a dynamic IP using HTTPS so there's no way to sign it but I trust myself) and put the proxy info into chrome.
Edit: I'd prefer to write it in python but I can do any language
Thanks in advance
P.S. Please don't give answers like just use GoAgent or tor or something. They don't fulfill my purpose.
If you're simply trying to proxy HTTP requests like GoAgent does then have a look at the URLFetch documentation for Google App Engine.
URL Fetch Python API Overview
If you're trying to proxy anything else, then Daniel is correct.
This isn't the sort of thing you can use GAE for.
I don't know where you got the idea that GAE "doesn't allow frameworks". Of course it does, anything that speaks WSGI (eg Django, Flask, Pylons) is fine. But GAE is a web platform: it's not an appropriate place to try and write any sort of bare-metal networking platform. Apart from anything else, bandwidth on GAE is fairly expensive.
And also I don't know where you think the GAE "front ends" are, as opposed to the "back ends". GAE is not split that way, AFAIK.
I don't really understand what exactly you are trying to do, but it sounds like a content delivery network (CDN) like Akamai might be more appropriate.
I want to develop an extremely lightweight web service with a RESTful JSON API. I will do all the session management on the server side. The solution will receive several 100k (or more) API calls an hour and return (compressed) JSON as response, it should be able to scale effortlessly.
Security is naturally important, but I want to avoid heavy weight frameworks like Django etc, and preferably will use a webserver like nginx or lighttpd instead of Apache.
At the server end, this is all I need:
user session management
security (protection against atleast the more common attacks such as cross site request forgery etc)
url routing
http utilities (e.g. compression)
I am aware of web2py, but its deployment options seems 'not well though out' at best - so far, I have been unable to get it to work with Apache, despite following the user manuals.
Can anyone suggest a python framework (and web server) best suited for this task?
if you want to go really lightweight, you might try wsgi itself without a framework, or maybe Flask. I understand wsgi runs on lighttpd, you'll get some hits on a Google search.
Try Pyramid. It's fast, lightweight and with a lot of options to configure your enviroment as you like...
I'm in the process of setting up a new web app and deciding whether to just do it with WSGI or go the full framework route with Django.
The app's foremost requirements:
1) The app has no UI what so ever and all of the data is exposed to clients via a REST api with JSON.
2) It will have data to persist so MongoDB & probably Amazon's SimpleDB will be used for the database side.
Is there a reason to use Django or can I get marginal speed improvement with WSGI only?
Previous server-side apps I've built were either with Java/Struts and Groovy/Grails on the JVM. My understanding is that Django is an MVC framework similar to Rails and Grails.
I've also played around with Google App Engine which uses WSGI as thin layer above your code for managing and routing requests.
I suggest you consider something between those two extremes. Flask is lightweight, very easy to use, and connects to your web server via wsgi. You can use regular python database connectors with it, and a few databases even have Flask-specific extension modules.
I have worked with Django for a couple of projects and I like it a lot, but since you are going to use mongoDB and a lot of JSON I suggest you use NodeJS as server side, with Express as framework, you can see a brief tutorial here:
http://howtonode.org/express-mongodb
One of the advantages of this is that you will use only javascript all along your project, I began working with this technology the last month in a Hackathon, and I can tell you that I'm very impressed of how fast and simple it is.
I've worked a bit with some django "apps" ,its really easy, but setting up the "apps" can be a bit of a long process. Django has a lot of nice features that you won't be using and I agree that you might be on one "extreme" here.
Disclaimer: I'm not very familiar with any of the things mentioned in the question title.
Would it be possible to use a browser control (like Webkit) as a frontend for a WSGI app (using a framework like Flask) without starting a local WSGI server?
Basically the requests and responses are managed by a middle layer between the HTML UI and the WSGI backend. A certain URI could mean "Local", for instance "local://" or something similar, and will be routed to the embedded WSGI app with all the original headers etc.
You will lose any features that a normal WSGI server provides unless you implement it yourself or somehow embed a server that is also usable via an API instead of real HTTP requests.
Now that I think of it, this is the only real requirement: A WSGI server that is callable via an API and not just real HTTP requests.
I know the usefulness of this is questionable (and maybe doesn't even make sense). My question is whether this is at all possible?
EDIT: Here's another way of putting it:
I want a single codebase to be both a web app and a desktop app, using an HTML frontend and a Python backend. I don't want to run a server on any port for the desktop app. What's the easiest way to achieve this?
It is in theory possible to write your own WSGI container that implements a full API and adapts that to WSGI. flup might bring some inspiration.
Earlier today I saw exactly what you're asking for -- a way to call WSGI through an API without actually connecting over the network. However, it shouldn't be that hard.
On a side note, you might want to look at PySide, of particular interest to you may be the ability to bind python elements to DOM events, so if you're just looking to trigger python code that's an even shorter route.
If you give some more detail on what you're hoping to achieve we might be able to dial it in for you.
Reviving this, since we're facing the same problem and are about to scale things up from a single view/widget to the whole app.
What I did was to simply set the base URL to something where I serve static content, and from a QRC file that's easy:
html = jinjatemplate.render(...)
self._mainFrame.setHtml(html.decode('utf-8'), Qt.QUrl('qrc:///Orsync/html/'))
For the communication, our HTML uses AJAX over jQuery for most things. You could wrap that in a layer that either does $.post(...) or api.post(...) like this:
self._mainFrame.addToJavaScriptWindowObject('api', self._webapi)
You'd need to decode the URL and create a request object yourself, but maybe that's not too hard to do? We use very few URLs currently (who are mapped directly to python objects/functions) so it's easy to do the mapping ourselves.
Data that goes back is just sent using QMainFrame.evaluateJavaScript(...), either as a direct Qt call or as a bunch of code lines fetched using $.getScript(...) (which just evaluates the code received).
I'm currently rebuilding things a bit using CherryPy, and it maps urls -> Python objects straight off, so I'm hoping there's something to be gained by that.
Otherwise, I would wish one could run QWebKit over named pipes or something similarly localized and not a tcp-socket. :)
We use a lot of of python to do much of our deployment and would be handy to connect to our TFS server to get information on iteration paths, tickets etc. I can see the webservice but unable to find any documentation. Just wondering if anyone knew of anything?
The web services are not documented by Microsoft as it is not an officially supported route to talk to TFS. The officially supported route is to use their .NET API.
In the case of your sort of application, the course of action I usually recommend is to create your own web service shim that lives on the TFS server (or another server) and uses their API to talk to the server but allows you to present the data in a nice way to your application.
Their object model simplifies the interactions a great deal (depending on what you want to do) and so it actually means less code over-all - but better tested and testable code and also you can work around things such as the NTLM auth used by the TFS web services.
Hope that helps,
Martin.
So, this question is friggin' old, but let me take a whack at it (since it keeps coming up in my google searches).
There's no officiall supported API for the on premise TFS (the MSFT hosted one has http://www.visualstudio.com/en-us/integrate/api/overview).
That said, you can always use Fiddler (http://www.telerik.com/fiddler) or something like it to inspect the calls that the web client for TFS is making to the server and do your magic to turn those into the scripts in python you want.
You'll need to run your python scripts under a service account that has TFS privs appropriate to what it is trying to do (read, update, confugure... whatever).
Since it sounds like you are just trying to read from TFS, this might be a really easy way for you to get what you want since an HTTP get to
http://yourserver/tfs/yourcollection/yourproject/_workitems#id=yourworkitemid
will hand you back (halfway) sane html payloads.
If you want lists of iterations or teams or whatever, then your service account needs to have the appropriate admin privileges and hit things like
http://yourserver/tfs/yourcollection/yourproject/_admin/_iterations
and use that response.