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helenio's avatar
helenio
Icon for Nimbostratus rankNimbostratus
Feb 26, 2014

local variable within same irule on all events

Hello,

 

I'd like to use a local variable to log all event within a certain irule.

 

Since now I have done like this:

 

when CLIENT_ACCEPTED { set logdebug 1 if {$logdebug != 0} {log local0.info "Client Connected, IP: [IP::client_addr], pool [LB::server pool]"} }

 

when HTTP_REQUEST { set logdebug 1 if {$logdebug != 0} {log local0.info "Client IP IP: [IP::client_addr], host [HTTP::host]"} }

 

when LB_SELECTED { set logdebug 1 if {$logdebug != 0} {log local0.info "in LB_SELECTED, IP [IP::client_addr]:[TCP::client_port], node [LB::server addr], pool [LB::server pool]"} }

 

But I'd like to avoid global variable and have to set logdebug to 1 only once on the irule ? Is that possible ? maybe with "session add " on the CLIENT_ACCPTED event ?

 

application delivery
devops
iRules

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  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Feb 26, 2014

    If I may add, and to expand on IheartF5's comments, global variables can be created anywhere and are indeed global to the entire device (other iRules, other VIPs, everything). There are good reasons to use global variables, but can also be troublesome if you're not careful. Also, while you can technically create a global variable anywhere, if you create one outside of RULE_INIT, or try to write to one later, you'll disable CMP.

     

    All variables, other than global ones, are "connection-scoped", meaning that they exist within the span of a single TCP connection. Because of this, you're best bet is usually to create them at the absolutely lowest layer (the CLIENT_ACCEPTED event) where they're guaranteed to exist everywhere else.