http://myfileserver/images/car/chevrolet.gif
I have this file server holding the files such as images, doc files etc. Now i want to intercept the http request and based on the file extension i want perform some action such as redirection to some other webpage.
What is the best and the easier way to accomplish this thing? I am using asp.net framework for my applications.
Pls suggest the approach.
Thx
If you are looking to intercept the request for specific file types, then go with an Http Handler. Here is the MSDN link explaining their usage - Http Handlers
In the WCF world if you're looking to handle an HTTP request with a different option based on the requested filetype, you may want to look into adding an IDispatchOperationSelector, which allows the service to route the code through a different operation. The default HTTP implementation is the WebHTTPDispatchOperationSelector, which is explained pretty well here and here.
If you want to remain in the Asp.Net world, I'd recomend going with custom message handlers. Here's an article by Mike Wasson explaining how these work & where they fall in the Asp stack.
Related
We have a number of existing clients that point to urls like:
http://sub1.site.com/images/image1.jpg
/images is a virutal directory that points to a directory that actually contains image1.jpg on that server.
We're moving all of the files out of this directory and onto a separate server that will not run this same application.
The file will now only be available at:
http://sub2.site.com/image1.jpg
What is the best way to make it so clients requesting
http://sub1.site.com/images/image1.jpg will get the content that now resides at http://sub2.site.com/image1.jpg?
A few requirements:
We need the actual content to be returned through that url - not a 302 response.
We cannot modify the IIS server configuration - only the web.config for the site
Again, we're running asp.net 3.5
Thanks.
Not totally sure this would work, but you could setup URL Routing on the old site so all requests are sent to a handler and within that handler you could do a web request to get the file from it's new location.
I use a variation of the process to map image URLs to different locations and my handler does some database queries to get the mapped relationship and provide the correct image. I don't see why you could do a web request to get the image.
Since you are using IIS7, you can use the built in URL rewrite module.
You would want an inbound and an outbound rule to change \images\image1.jpg to \image1.jpg
It can get pretty involved, but this should be rather simple.
Assuming you can add handlers to your site (as in add a DLL to your /bin directory in the site) and with the restriction that you can't send 302 responses for better performance, then alternatively you could write a custom handler to grab all requests that match that URL pattern, do the web request for the sub2.site image from the original site via web client code, then serve it back out of the original site, sub1.site.com.
See How To Create an ASP.NET HTTP Handler by Using Visual C# .NET for the very basics of creating and setting up a custom handler. Then use the HttpWebRequest to make the request of sub2.site.com, as in the guide A Deeper Look at Performing HTTP Requests in an ASP.NET Page. Plus a little other code to handle errors, timeouts, passing the image through with as little processing and memory usage as possible, etc.
Depending on the response time/lag between the two servers, this may be slow, but it would fit all your requirements. But if the point of moving the images to site 2 was for performance (CPU or memory) or bandwidth limitations, then this solution would nullify any gains — and would actually make things worse. But if they were moved for other business or technical reasons though, then this solution might be helpful still.
If you have other control over the server or anything upstream from the server, you could use mod_proxy (or similar Windows/IIS tool) to intercept those URLs and forward them to another server and respond back with the real request. Depending on your network configuration and available servers, this could be the simplest, best performing solution.
Can IIS be configure to forward request to another web server? on serverfault has a quick process and link for an IIS 7.5 solution.
I'm experimenting with javascript and css caching in ASP.NET MVC. Is it possible to intercept calls to the server for these types of files?
For example, if a request gets to the server for
~/Scripts/Something.CurrentVersion.js
I would like to intercept this call and tell the server to return
~/Scripts/SomeOtherFile.js
Would it be possible to hook into some event or create a new module or HttpHandler to accomplish this?
Checkout these links for different ways:
http://weblogs.asp.net/rashid/archive/2009/04/28/script-and-css-management-in-asp-net-mvc.aspx
http://weblogs.asp.net/rashid/archive/2009/05/02/script-and-css-management-in-asp-net-mvc-part-2.aspx
http://www.codeproject.com/KB/aspnet/combineMinify.aspx
Yep. HttpHandler is certainly one way to go. Beware of the integration to IIS though - to have full control over mapping you have to run it in integrated mode - otherwise IIS itself will process request BEFORE it will get to the worker process
I'm setting up my site to receive info from people via text message. The way it works is they text a number, that service then sends an HTTP POST to a url I specify. I've heard that .asmx files are better than .aspx files because they don't go through the whole page lifecycle. However, I don't really understand how to get a .asmx file running, and can you even call it with a POST, ie, www.mysite.com/webservice.asmx? I know I can make it work with a .aspx file, but I wanted to check to see if there was a better way before I undertake this endeavor.
Thanks for your insight!
While any extension can be mapped to any handler in ASP.NET, by default .aspx is mapped to page handler and .asmx is mapped to Web service handler. I think you are looking for .ashx which represents a generic simple handler. You just need to implement ProcessRequest method of the IHttpHandler interface after adding one to your project (Add New Item -> Generic Handler).
The .ashx works well if you want to manually process the request. Only if you want to provide a Web service (e.g. SOAP), you should go with .asmx. As a consequence, the best solution depends on the format of the HTTP POST request they send. If they send raw data in POST with their own specific protocol, go with .ashx. Otherwise, if they are using a standard RPC (SOAP, XML-RPC, ...) protocol, .asmx is probably better.
Create an .asmx file with Visual Studio. It should create a template with a HelloWorld method. Browse to it with your favorite browser and you'll actually get an explanation on how to post requests to it using various methods.
There is another type you haven't mentioned: ashx. However, in your case, a webservice (asmx) would make sense.
Does HTTP PUT have advantages over HTTP POST, particularly for File Uploads? Data transfer should be highly secure. Your ideas / guidance on this will be of great help.
PUT is designed for file uploads moreso than POST which requires doing a multipart upload, but then it comes down to what your server can do as to which is more convenient for you to implement.
Whichever HTTP method you use, you'll be transmitting data in the clear unless you secure the connection using SSL.
I think the choice of PUT vs. POST should be more based on the rule:
PUT to a URL should be used to update or create the resource that can be located at that URL.
POST to a URL should be used to update or create a resource which is located at some other ("subordinate") URL, or is not locatable via http.
Any choices regarding security should work equally with both PUT and POST. https is a good start, if you are building a REST API then keys, authorisation, authentication and message signing are worth investigating.
Does HTTP PUT have advantages over HTTP POST, particularly for File Uploads?
You can use standard tools for sending the data (i.e. ones that don't have to be aware of your custom scheme for describing where the file should be uploaded to or how to represent that file). For example, OpenOffice.org includes WebDAV support.
Data transfer should be highly secure
The method you use has nothing to do with that. For security use SSL in combination with some form of authentication and authorization.
I'm doing some researching on switching from Apache to Nginx as a reverse proxy in front of a Grails application on the backend. I'm playing around with some URL rewriting and have run into an issue with the response being sent back from my back end. I can handle the location header rewrite but I'm wondering what the best way to process the actually content is for link and such.
Is nginx_substitutions_filter the preferred method or is there another module that folks use to do content replacement in the response body?
I've thought about creating a Grails plugin to handle rendering the correct content based on additional request headers but now I'm thinking that would be best handled outside the application to allow for the most flexibility and loose coupling.
Are there any articles about best practices for doing URL rewriting/response post processing for reverse proxy scenarios?
You can use the Lua module to capture the response and manipulate it like a Lua string. Silly example to upper case the output:
res = ngx.location.capture('/some/path')
ngx.print(string.upper(res.body))
see http://wiki.nginx.org/HttpLuaModule#ngx.location.capture
If you want to replace only the headers, HeadersMore 3rd party module is great for that.
Other than that, susbstiution module seems to be the only option.
But I would suggest you make the backend return the correct page. Modifying every response uses resources and takes time.