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Dan44's avatar
Dan44
Icon for Altostratus rankAltostratus
Nov 22, 2019

URL Rewriting

Hello together

Does anyone have experience with URL rewriting wit help of an iRule or a rewrite profile?

For a migration i have to rewrite a url. We have two pools (old-web, new-web) containing IIS web servers.

The url like:

https://www.myweb.com/webapp/v40/typ?filter=typ%3D10 should be rewritet to https://app.myweb.com/v40/typ?filter=typ%3D10

The problem is that app.myweb.com does't expect webbapp in the path, therefore it must be sent without /webapp/ to the host.

 i first tried it with an irule, this does not work unfortunately

when HTTP_REQUEST {
if {[string tolower [HTTP::host]] starts_with "www.myweb.com" && [string tolower[HTTP::path]] eq "/webapp/"} {
    HTTP::header replace Host "app.myweb.com"
    HTTP::uri "/"
	pool new-web 80
 
  }
}

Then i tried it with an rewrite profile

 Does anyone have any idea what I'm doing wrong?

devops
iRules
LTM

2 Replies

  • gersbah's avatar
    gersbah
    Icon for Cirrostratus rankCirrostratus
    Nov 22, 2019

    I have no experience with rewrite profiles, but I may be able to help with that iRule.

    Your condition only matches when the path equals /webapp/, but you want it to match when it starts_with.

    Then after that it would rewrite the entire url to "/", not just remove the /webapp/ portion of the path.

    Instead you should be able to almost 1:1 use this example from here https://devcentral.f5.com/s/articles/irules-101-14-tcl-string-commands-part-2

    when HTTP_REQUEST {
   set uri [HTTP::uri]
   if { $uri starts_with "/axess2" } {
      HTTP::uri [string range $uri 7 end]
      pool pool1
   }
}

    Adjusted to your own example:

    when HTTP_REQUEST {
    set uri [HTTP::uri]
    if {[string tolower [HTTP::host]] eq "www.myweb.com" && [string tolower $uri] starts_with "/webapp/"} {
        HTTP::header replace Host "app.myweb.com"
        HTTP::uri [string range $uri 7 end]
    	pool new-web
      }
    }
  • Dan44's avatar
    Dan44
    Icon for Altostratus rankAltostratus
    Dec 04, 2019

    hi

    thanks. your example helped us to solve the problem.