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Dbow_21284's avatar
Dbow_21284
Icon for Nimbostratus rankNimbostratus
May 21, 2009

HTTPS VIP - Redirect to Maintenace Page

Hey everyone,

 

 

Fairly new to F5s, used to the GUI stuff (laught all you want)! Anyway, I have a site that is HTTPS only, and I need to redirect to a maintenance page if all the nodes in pool are down. I see its easy in a HTTP VIP via HTTP profile fallback parameter or via an iRule to look at the active_members in a pool and redirect to maintenance page if not available.

 

 

But for HTTPS, I cant find an iRule to do this. I assume https_request syntax does not exist.

 

 

Does anyone have a iRule that does this? Or if not an iRule how else can you do it? Do I have to offload the SSL cert to the LB?

 

 

Your help is appreciated.

 

 

Dave

 

 

PS: I looked for topic on this with no luck. Sorry if I duplicated. Thanks again in advance.
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  • JRahm's avatar
    JRahm
    Icon for Admin rankAdmin
    May 21, 2009
    I think Hoolio posted a solution a while back that only offloads if all the pool members are down. Let me dig...
  • Dbow_21284's avatar
    Dbow_21284
    Icon for Nimbostratus rankNimbostratus
    May 21, 2009
    I found this one:

     

     when CLIENT_ACCEPTED {      
  Set this flag to 1 to decrypt the SSL and send a redirect to the client.   
 Set to 0 to pass the SSL through without decrypting it.      
  
 set maintenance_redirect 1      
 log local0. "[IP::client_addr]:[TCP::client_port]: Received connection with maintenance flag set to $maintenance_redirect"      
  Check if the maintenance flag is disabled (set to 0)      
 if {$maintenance_redirect==0}{         
  
  Disable the client SSL profile so the HTTPS traffic is passed through encrypted to the node         
 SSL::disable         
  Disable the HTTP profile as we're not going to redirect this request         
 HTTP::disable         
 log local0. "[IP::client_addr]:[TCP::client_port]: Maintenance flag is disabled"      
 }   
 }   
  
  
 when HTTP_REQUEST {      
  The HTTP_REQUEST event is only triggered if the maintenance flag is enabled and the client SSL and HTTP profiles are left enabled      
  Redirect the client      
 HTTP::redirect https://maintenance.example.com      
 log local0. "[IP::client_addr]:[TCP::client_port]: Redirecting request"  }

     

     

    But I dont see in the code where it detects if all the pool members are available or not.
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    May 21, 2009
    Thanks Citizen. The codeshare example (Click here) has a slight improvement over the original post in that the TCP connection is closed. This prevents the client from being redirected if they reuse a TCP connection after the pool member has come back up.

     

     

    ddenbow, that example was for a different scenario, so it used a manual switch to enable/disable the decryption and redirection. The codeshare example should do what you're looking for.

     

     

    Aaron
  • Dbow_21284's avatar
    Dbow_21284
    Icon for Nimbostratus rankNimbostratus
    May 21, 2009
    Unbelieveable this got answered in less than an hour! Thanks so much guys I really apprecitea it!
  • Dbow_21284's avatar
    Dbow_21284
    Icon for Nimbostratus rankNimbostratus
    May 21, 2009
    Ok I see that you have to have SSL offloaded though, which I am not currently doing for the site in question (which is OWA BTW).

     

     

    Is there a way to do this without offloading SSL to the LTM?
  • JRahm's avatar
    JRahm
    Icon for Admin rankAdmin
    May 21, 2009
    Well, the beauty is that it is not offloading unless the servers are all down. No way around offloading if you want to respond to the client.
  • JRahm's avatar
    JRahm
    Icon for Admin rankAdmin
    May 21, 2009
    yes, and it will sit dormant until the scenario where all servers are down.