Fetching content from external source

Aron,

 

 

Can you explain what are you trying to do by making an out of band request to a pool? Are you determining if the client request is valid? Or something else?

 

 

Actually I want to do a lookup from an external HTTP (RESTful) server to get a Mobile Phone Number (MDN) from the IP of the requesting client e.g. "/[IP::client_addr]" these mobile phones route through the F5 to the internet at large.

 

 

Yes it is an out-of-band socket connection to a 3rd host - but in the event the 3rd host is down or it fails to provide a valid MDN then the out-of-band operation does nothing and the out-of-band logic should be ignored.

 

 

Future Work: If I couldn't look up the MDN I might re-try the out-of-band operation again once each 30 seconds as long as the connection is up.

 

 

Future Work: Once I have an MDN (if and only if I have one) then I might do some HTML injection on the response or a redirect.

 

 

Here is some proposed code - hopefully it will work any advice?

 

 

 

     
      when CLIENT_ACCEPTED {      
         flag as new request needing lookup      
        set lookup 1      
         set flag to indicate if we had a valid lookup.      
        set keyfound 0         
      }       
      when HTTP_REQUEST {      
        if {$lookup == 1} {      
           we are doing a 3rd host out-of-band lookup     
           save original request      
          set req [HTTP::request]      
      
           inject a lookup URI in place of original request      
          HTTP::uri "/[IP::client_addr]"      
      
           set pool to lookup server pool called "mdn_lookup"      
           hopefully the pelow "pool mdn_lookup" is not sticky    
           such that the later HTTP::retry $req done in the   
           HTTP_RESPONSE_DATA will not go back to this pool, I    
           can not set it to another "normal" pool after this    
           out-of-band processing is done as the requests are    
           going to the internet at large (not servers under    
           my control).    
          pool mdn_lookup      
        }        
      }      
      when HTTP_RESPONSE {      
        if {$lookup == 1 }{      
           collect first response (from lookup server) only      
          HTTP::collect      
    
          if {[HTTP::status] == 200} {      
         200 OK we got an IP lookup from the RESTful server      
         we have to have a valid MDN or MobileNumber, all other         
         responses imply no lookup.        
              
         collect first response (from lookup server) only        
            HTTP::collect $clength      
                
             valid lookup we have a MDN and can do something with it        
            set keyfound 1        
          }      
        }  
         normal path for NOT out-of-band responses  
      }      
      when HTTP_RESPONSE_DATA {      
         Once the lookup is done there is NO pool to go back to      
         as the clients are mobile phones going out to the internet        
            
        if {$keyfound == 1} {      
      set mdn [HTTP::payload]      
      log local0. "mdb_lookup gives <<$mdn>>"          
       we want to actually do something with it later but       
       this iRULE is a proof of concept.  Typical we would      
       alter the true response based on the mdn we just set.      
       If we never get a valid MDN we the request will       
       proceed as if the out-of-band lookup never happened.      
        }  else {      
      log local0. "mdb_lookup gives NULL"      
        }      
        HTTP::retry $req        
              
         NO ERROR CHECKING YET ....      
         if mdn_lookup is dead/non-existant I just want to      
         process things as if there was no out-of_band code      
            
         re-set flag so that subsequent response to re-tried       
         request from real server is not processed as an MDN      
         lookup - eventually I might put in retry every 15       
         second logic until we get a valid lookup      
        set lookup 0      
      }