A twist on the 404 status code

This is what I have so far:

 

 

when HTTP_RESPONSE {

 

if { [HTTP::header location] contains "http://www.mydomain.com/404.htm" }

 

HTTP::header replace "Status" "404"

 

}

 

}

My example doesn't work of course. Doh!

you may try HTTP::respond command

 

 

http://devcentral.f5.com/Wiki/default.aspx/iRules.HTTP__respond

Hi Mike,

 

 

It sounded like you wanted to change the 200 status to a 400. But your test rule is trying to rewrite a redirect (which would be a 30x status) to a 404. Can you use a browser plugin like HttpFox for Firefox or Fiddler for IE to determine exactly what the application is sending back and then describe what you want to do with it?

 

 

Unfortunately, HTTP::status can only be used to get (not set) the status of the response. So to "change" the status you could need to send your own response using HTTP::respond. It's fairly simple if you can send your own response content. Or if you need to leave the response data from the server in tact, you'd need to collect the payload for the specific responses and then use HTTP::respond to send a 404 response with the original payload. You can check the HTTP::collect wiki page (Click here) for examples.

 

 

Aaron

HTTP::respond is what you are looking for, mentioned above. You will also need to include a 404 page, by setting it in a variable possibly at RULE_INIT, if it's static.

 

 

Regards,

Thanks for the great direction everyone. To solve the immediate need, I will place our 404 html content in the iRule like so:

 

 

when HTTP_REQUEST {

 

if { [HTTP::uri] contains "404.htm" } {

 

HTTP::respond 404 content {

 

 

 

Custom 404

 

 

 

All this content comes from our real 404.htm page, but is manually copied into here.

 

 

 

}

 

}

 

}

 

 

This is just the first step. I want to try to implement the HTTP::collect and do this the right way as I learn more about iRules. Once again, thanks for helping!

 

 

-Mike

Hi Mike,

 

 

I'm not sure how a search engine will react if the app redirects with a 302 to a page which the app sends a 200 with content indicating the page couldn't be found. You might want to catch the original 302 if the location contains the custom "404" page and respond with an actual 404 status.

 

 

Aaron

Excellent point Aaron. We will have to change the way this works, because it is issueing a 302 before the 404 (defeats the original purpose). I think we will modify the iRule to detect the server response containing status 302 and the uri of the 404 page, and instead respond with a 404 status and the 404 content.

 

 

Good catch. Thank you.

 

 

Mike

Something like this should work for this:

 
 when HTTP_RESPONSE { 
  
     Check if response is a redirect and the Location header contains the 404 page 
    if { [HTTP::is_redirect] and [HTTP::header Location] contains "http://www.mydomain.com/404.htm"}{ 
  
        Send a 404 with custom content 
       HTTP::respond 404 content { 
           
           
          Custom 404 
           
           
          All this content comes from our real 404.htm page, but is manually copied into here. 
           
           
       }  
    } 
 } 
 

Aaron

This looks good. I'll modify our iRule and do some testing. I think this is really close to what we need.

 

 

Thank you.

 

Mike