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DannyF_69324's avatar
DannyF_69324
Icon for Nimbostratus rankNimbostratus
Aug 18, 2011

iRule to display remote content through fake URI

Hey Guys,

 

I know there is an iRule like this already out there, but I can't seem to find it. Anyway hopefully one of you guys can help me out.

 

I'm going to be creating several reseller sites for a company each for which will display their own content. All of these sites will then use only one help site which we created so all the resellers can link to. The problem is that if we create the link to our help they will leave the site and will then be redirected to the help site. We want to prevent this by using an iRule that could display the remote site's content when any specific URI is given.

 

 

For example:

 

 

The help domain would be https://helpsite.com/help/

 

 

The resellers domains would be:

 

 

http://reseller1.com

 

http://reseller2.com

 

http://reseller3.com

 

 

 

If any of the reseller sites call for http://reseller1.com/help/ we want the help site's content (https://helpsite.com/help/) to be display under the /help/ URI of any reseller site.

 

 

I remember seen something like this before but I can't remember the name of this iRule or what functions were used to create this.

 

 

Thanks for any help you can provide.

 

 

--

 

Danny Fuentes

 

application delivery
dev
devops
iRules
  • Ed_Hammond_2611's avatar
    Ed_Hammond_2611
    Icon for Nimbostratus rankNimbostratus
    Aug 19, 2011
    So from the outside you want the http://reseller1.com/help to go to the servers actually supporting http://help site.com/help ? That would be a pool selection based on the hostanme and URI path. Use the "pool" command.

     

     

    If you are looking to redirect the user's browser, use the HTTP::redirect or :: response commands.
  • The_Bhattman's avatar
    The_Bhattman
    Icon for Nimbostratus rankNimbostratus
    Aug 19, 2011
    To expand on Ed's description

    One way you could do this is to create pool pointing to the IP address for https://helpsite/help. In my example let's called it pool_helpsite.

    Once that is created you would use the following irule 

    
when HTTP_REQUEST {
   switch -glob [string to lower [HTTP::uri]
   "/help"-
   "/help/"  {  
HTTP::header replace Location "https://helpsite.com/help"
 Pool pool_helpsite
snat automap
}
   }
}

    The snat command basically ensures asynchronise routes to devices in a pool where they are not the gateway.

    I hope this helps

    Bhattman
  • DannyF_69324's avatar
    DannyF_69324
    Icon for Nimbostratus rankNimbostratus
    Aug 19, 2011
    Hey Bhattman,

    I tried the iRule you suggested, but I'm getting an error. Seems as if there is an open bracket missing somewhere but I'm not very familiar with TCL so I can't really find the place. The error I'm getting is 

     error: line 3: [parse error: extra characters after close-quote] [- "/help/" { HTTP::header replace Location "https://helpsite.com/help" Pool pool_helpsite snat automap } ] line 4: [undefined procedure: /help/] ["/help/" { HTTP::header replace Location "https://helpsite.com/help" Pool pool_helpsite snat automap }] line 10: [command is not valid in the current scope] [}]

    I replaced the variables with my own, but for the example posted above I used the same variables in the sample iRule.

    Thanks for the help.
  • DannyF_69324's avatar
    DannyF_69324
    Icon for Nimbostratus rankNimbostratus
    Aug 19, 2011
    Thanks Michael looks like that took care of the problem I had trying to add the iRule. Now the problem that I'm seeing is that the iRule does not seem to be parsing the host header into the request to the IP. The remote site is running with NameVirtualHost and since no host header appears to be passing to the iRule it defaults to the first available site under that IP. Is there a way to fix that?

     

     

    Thanks again for the help I may be able to work around this problem if it cant be done.
  • Michael_Yates's avatar
    Michael_Yates
    Icon for Nimbostratus rankNimbostratus
    Aug 19, 2011
    Hi DannyF,

    I modified the HTTP::header portion to look for the Host value. Place the exact IIS Host Head name in that area and you should be good to go. 

     
when HTTP_REQUEST {
    switch -glob [string tolower [HTTP::uri]] {
    "/help" -
    "/help/" {
        HTTP::header replace Location "https://helpsite.com/help"
HTTP::header replace "Host" "helpsite.com"
        pool pool_helpsite
        snat automap }
    }
}
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Aug 22, 2011
    Nice one Michael. Note that you can remove the -glob flag if you're not using wildcards in the switch statement to save some CPU cycles.

     

     

    Aaron