Forum Discussion

Leo_T_144084's avatar
Leo_T_144084
Icon for Altocumulus rankAltocumulus
Aug 06, 2014

Maintenance page iRule. Need redirect AND rewrite.

Hi :)

 

I am looking to create an irule to throw a maintenance page redirect if our entire pool is down. This is what I have, which works.

 

when HTTP_REQUEST { Check if the VS default pool has no active members if { [active_members [LB::server pool]] < 1 }{ HTTP::redirect "http://maint.xyz.com" } }

 

The issue is, I need to be able to ALSO rewrite the url so that if the condition above is met, it redirects the user to maint.xyz.com and then rewrite their URL to www.xyz.com.

 

Thoughts?

 

Thanks!

 

application delivery
availability
devops
iRules
LTM
management
  • Leo_T_144084's avatar
    Leo_T_144084
    Aug 22, 2014

    OK, this is what i did which did the trick:

    Added the maintenance server as a node on the LTM Create a pool called maintenance_pool and added my maintenance page server to it. Created an irule called maintenace_page with the following in it:

    when HTTP_REQUEST {
    if {[active_members [LB::server pool]] < 1 }  {
        pool maintenance_pool
    }
 }

    Applied the rule to the Virtual servers needed. Voila. Works like a charm!

    I really did not want to host the maintenance page on the LTM as we often change those pages and it is easier for the DEVs to do it directly on the server itself.

    Thanks again for your help OTS02.

  • OTS02's avatar
    OTS02
    Icon for Cirrus rankCirrus
    Aug 06, 2014

    Are maint.xyz.com and www.xyz.com both hosted on your LTM?

     

  • OTS02's avatar
    OTS02
    Icon for Cirrus rankCirrus
    Aug 07, 2014

    I do not know of a way to do that. Once you redirect, you have no more control over their connection. May I ask why you want to do that? BTW, you can accomplish the redirect from the http profile, by placing 'maint.xyz.com' in the fallback host window.

     

  • OTS02's avatar
    OTS02
    Icon for Cirrus rankCirrus
    Aug 08, 2014

    The LTM can serve out a good looking page (with images) from an iRule. It does take some doing though. You have to encode the images in base64 and load them into a class file. Here is a good link to some work that nitass has done: https://devcentral.f5.com/questions/maintenance-page

     

    You will, of course, need to add some logic to keep an eye on the www.xyz.com pool. If you simply change the host header, after serving the maintenance page, you will create a race condition that will probably be terminated by the LTM.

     

  • Leo_T_144084's avatar
    Leo_T_144084
    Icon for Altocumulus rankAltocumulus
    Aug 12, 2014

    I've been looking through your suggestion and working with Nitass' code. I was able to host the site on the LTM and get it to come up when all of the pool members come up, without images. Ideally, I would like to do this. Redirect to maint.xyz.com and replace the URL with www.xyz.com. Our maintenance pages often change so ideally I would redirect to a server with the maint page instead of having to recreate an irule every time the devs have to update the page. Of course the rewrite doesn't work.

     

    when HTTP_REQUEST {
     Check if the VS default pool has no active members
    if { [active_members [LB::server pool]] < 1 }{
        HTTP::redirect "http://maint.xyz.com"
        HTTP::header replace Host "www.xyz.com"
       }
}
    • chrenter_175530's avatar
      chrenter_175530
      Icon for Nimbostratus rankNimbostratus
      Oct 29, 2014
      Using these methods for pool failure, is there a way to redirect/rewrite to an internal web server without "redirect" to the client? We have a complex maintenance page that makes it extremely hard to maintain it on the F5. Right now, the following code triggers the condition, but the client receives connection reset. The intent is to have the F5 proxy the maintenance page. when HTTP_REQUEST { if {[active_members [LB::server pool]] < 1 } { pool maintenance_pool } } Thank you for any help!
  • Leo_T_144084's avatar
    Leo_T_144084
    Icon for Altocumulus rankAltocumulus
    Aug 22, 2014

    OK, this is what i did which did the trick:

    Added the maintenance server as a node on the LTM Create a pool called maintenance_pool and added my maintenance page server to it. Created an irule called maintenace_page with the following in it:

    when HTTP_REQUEST {
    if {[active_members [LB::server pool]] < 1 }  {
        pool maintenance_pool
    }
 }

    Applied the rule to the Virtual servers needed. Voila. Works like a charm!

    I really did not want to host the maintenance page on the LTM as we often change those pages and it is easier for the DEVs to do it directly on the server itself.

    Thanks again for your help OTS02.