iC2I: What Pools Rely on This Server?

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.

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

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.

Hi DannyF,

I fixed the syntax.

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

If you use the iRule Editor (http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/1/aft/1172053/showtab/groupforums/Default.aspx) it will help you with the Syntax issues.

Hope this helps!

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.

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 }
    }
}

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