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whisperer's avatar
whisperer
Icon for MVP rankMVP
Apr 25, 2013

Virtual Statement String Processing

Having some issues with the 'virtual' statement within a v9 iRule. The code basically includes the following pertinent statements:

 

when HTTP_REQUEST {

 

set app_pool [LB::server pool]

 

virtual "${app_pool}_SOME_STRING"

 

unset app_pool

 

}

 

The error then seen in logs is the following:

 

TCL error:

 

HTTP_REQUEST - Failed listener_lookip: virtual line 1 invoked from within virtual ${app_pool}_SOME_STRING

 

 

In this case, lets assume the following:

 

Pool Name: "my_app"

 

VIP: "my_app_SOME_STRING"

 

Thusly, the Pools and VIPs exist....

 

Perhaps I have either (a) wrong syntax somewhere or (b) the 'app_pool' variable is not being set properly?

 

 

application delivery
dev
devops
iRules

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  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Apr 25, 2013
    Two things:

     

     

    1. Please add a log statement that shows the value of app_pool.

     

     

    2. Which version of 9.x? The ability to direct traffic with the virtual command didn't exist before 9.4.0.

     

  • whisperer's avatar
    whisperer
    Icon for MVP rankMVP
    Apr 25, 2013
    LTM Version is 9.4.7.

     

     

    If 'app_pool' has no set value, shouldnt the variable still be processed w/ potentially a null string used as its value? It looks like the variable is not even being parsed.
  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Apr 25, 2013
    Try this and review/report your findings: 

    
when HTTP_REQUEST {
    set app_pool [LB::server pool]
    log local0. "app_pool = $app_pool"
    log local0. "virtual = ${app_pool}_SOME_STRING"
    virtual "${app_pool}_SOME_STRING"
    unset app_pool
}