A bit new to processing the irules and have a question which I hope the group can asisst with. Scenario: User URL: http://site.company.com/study1 F5 will rewrite the URL -> /ServiceStudyDB to the server. Return traffic from the Server will then need to be rewritten back to /study1 for the client. Using the below config, appears to be a redirect loop. when HTTP_REQUEST { Disable the stream filter for client requests if {[HTTP::uri] contains "/study1"}{ HTTP::uri "/ServiceStudyDB" HTTP::header replace Accept-Encoding [string map -nocase {"" "none"} [HTTP::header Accept-Encoding]] STREAM::disable } } when HTTP_RESPONSE { if {[HTTP::header value Server] contains "IIS"}{ set study1_uri [string map -nocase {"/ServiceStudyDB" "/study1"} [HTTP::header "Location"]] HTTP::header replace Location $study1_uri } } The reason for keeping the /studyx is that we will eventually be honing in on this to make sure this gets routed to a specific backend node.

Seems like there's plenty of over-complication in your current rule. You don't need to overwrite server responses as only the URI was modified. It does not violate cross-domain policy and user browser has no problem with it. Furthermore, it has no awareness the response content did not originate from the originally requested directory. The iRule below should cover your needs: when HTTP_REQUEST { if {[HTTP::uri] contains "/study1"} { HTTP::header remove "Accept-Encoding" HTTP::uri "/ServiceStudyDB" STREAM::disable } }

Thank you for the response and I have tested the simplified iRule. The problem exists when the server has a 302 from within itself to send the requesting URL to /ServicesStudyDB/login.aspx.... Therefore, are "response" rewrite is also required as the requesting browser should only know about /study1. Keep in mind the reason for this is that as we add /study2, /study3, etc.. we will be sending to specific backend nodes and need to keep the URI string on the request in order to send to the correct backend server. Seems the response is the loop. I have this working on the Cisco ACE with some major manipulation and being tasked with getting this to workon on the F5 (which seems possible).

For rewriting redirect locations, check out https://devcentral.f5.com/articles/rewriting-redirects

URL Rewrite - No redirection

19 Replies

Hannes_Rapp_162
Nacreous
Oct 22, 2014
Seems like there's plenty of over-complication in your current rule. You don't need to overwrite server responses as only the URI was modified. It does not violate cross-domain policy and user browser has no problem with it. Furthermore, it has no awareness the response content did not originate from the originally requested directory.

The iRule below should cover your needs:

when HTTP_REQUEST { if {[HTTP::uri] contains "/study1"} { HTTP::header remove "Accept-Encoding" HTTP::uri "/ServiceStudyDB" STREAM::disable } }
- jmeuse35_166730
  Nimbostratus
  Oct 22, 2014
  Thank you for the response and I have tested the simplified iRule. The problem exists when the server has a 302 from within itself to send the requesting URL to /ServicesStudyDB/login.aspx.... Therefore, are "response" rewrite is also required as the requesting browser should only know about /study1. Keep in mind the reason for this is that as we add /study2, /study3, etc.. we will be sending to specific backend nodes and need to keep the URI string on the request in order to send to the correct backend server. Seems the response is the loop. I have this working on the Cisco ACE with some major manipulation and being tasked with getting this to workon on the F5 (which seems possible).
Hannes_Rapp
Nimbostratus
Oct 22, 2014
Seems like there's plenty of over-complication in your current rule. You don't need to overwrite server responses as only the URI was modified. It does not violate cross-domain policy and user browser has no problem with it. Furthermore, it has no awareness the response content did not originate from the originally requested directory.

The iRule below should cover your needs:

when HTTP_REQUEST { if {[HTTP::uri] contains "/study1"} { HTTP::header remove "Accept-Encoding" HTTP::uri "/ServiceStudyDB" STREAM::disable } }
- jmeuse35_166730
  Nimbostratus
  Oct 22, 2014
  Thank you for the response and I have tested the simplified iRule. The problem exists when the server has a 302 from within itself to send the requesting URL to /ServicesStudyDB/login.aspx.... Therefore, are "response" rewrite is also required as the requesting browser should only know about /study1. Keep in mind the reason for this is that as we add /study2, /study3, etc.. we will be sending to specific backend nodes and need to keep the URI string on the request in order to send to the correct backend server. Seems the response is the loop. I have this working on the Cisco ACE with some major manipulation and being tasked with getting this to workon on the F5 (which seems possible).
shaggy_121467
Cumulonimbus
Oct 22, 2014
For rewriting redirect locations, check out https://devcentral.f5.com/articles/rewriting-redirects
- jmeuse35_166730
  Nimbostratus
  Oct 22, 2014
  As I work through this I think the issue is in the matching for the URI and replacement. Assume the request is: http://site.company.com/study1 and sending to the server as http://site.company.com/ServiceStudyDB. The server is sending back a 302 for ServiceStudyDB/login.aspx. Therefore, I think I need a wildcard that anything after /ServiceStudyDB will continue. ie: Would I not want to make sure that if anything is after the initial replacement that it continues?
- shaggy_121467
  Cumulonimbus
  Oct 22, 2014
  i'm not sure i understand - are you looking to retain the URI portion after the initial /xxx/? so /ServiceStudyDB/login.aspx would be /study1/login.aspx when it returned to a user?
- jmeuse35_166730
  Nimbostratus
  Oct 22, 2014
  That is correct. On a nother platform I can rewrite the URL as "/study1(.*)" and replace with "ServiceStudyDB%1" and vice versa on the response. Sorry to make this confusing, but I believe this is where the redirect is looping.
shaggy
Nimbostratus
Oct 22, 2014
For rewriting redirect locations, check out https://devcentral.f5.com/articles/rewriting-redirects
- jmeuse35_166730
  Nimbostratus
  Oct 22, 2014
  As I work through this I think the issue is in the matching for the URI and replacement. Assume the request is: http://site.company.com/study1 and sending to the server as http://site.company.com/ServiceStudyDB. The server is sending back a 302 for ServiceStudyDB/login.aspx. Therefore, I think I need a wildcard that anything after /ServiceStudyDB will continue. ie: Would I not want to make sure that if anything is after the initial replacement that it continues?
- shaggy
  Nimbostratus
  Oct 22, 2014
  i'm not sure i understand - are you looking to retain the URI portion after the initial /xxx/? so /ServiceStudyDB/login.aspx would be /study1/login.aspx when it returned to a user?
- jmeuse35_166730
  Nimbostratus
  Oct 22, 2014
  That is correct. On a nother platform I can rewrite the URL as "/study1(.*)" and replace with "ServiceStudyDB%1" and vice versa on the response. Sorry to make this confusing, but I believe this is where the redirect is looping.

jmeuse35_166730

Nimbostratus

Oct 22, 2014

Here is the solution that works:

when HTTP_REQUEST {

if {[HTTP::uri] contains "/study1"} {
  HTTP::header remove "Accept-Encoding"
  HTTP::header replace Location [string map -nocase {"study1" "ServicesStudyDB"} [HTTP::header Location]]
  HTTP::uri "/ServicesStudyDB"
  HTTP::uri [string map -nocase {"study1" "ServicesStudyDB"} [HTTP::uri]]
  STREAM::disable  
}

} when HTTP_RESPONSE { if {[HTTP::header Content-Type] contains "text"}{

set study1_uri [string map -nocase {"/ServicesStudyDB" "/study1"} [HTTP::header "Location"]] HTTP::header replace Location $study1_uri

HTTP::header replace Location [string map -nocase {"ServicesStudyDB" "study1"} [HTTP::header Location]]
  Replace 'old_text' with 'new_text'
STREAM::expression {@ServicesStudyDB@study1@}
 Enable the stream filter for this response only
STREAM::enable
}

}

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URL Rewrite - No redirection

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