iRule to strip out a query variable

 

I'm building an iRule that strips off one of the query variables, namely "_". From the logs and documentation this _should_work but it is NOT setting the HTTP::uri as anticipated.

 

 

F5: BIG-IP 9.2.4 Build 13.1

 

---------------------------------------------------------------------

 

when HTTP_REQUEST {

 

if {[HTTP::query] contains "&_="} {

 

log local0. "--------------------------"

 

log local0. "HTTP::uri: [HTTP::uri]"

 

log local0. "HTTP::query: [HTTP::query]"

 

set newquery ""

 

set namevals [split [HTTP::query] "&"]

 

for {set i 0} {$i < [llength $namevals]} {incr i} {

 

set params [split [lindex $namevals $i] "="]

 

set pnum {$i+1}

 

if {[lindex $params 0] != "_"} {

 

 

only prepend a & when not the first variable

 

if { $newquery contains "&" } {

 

append newquery "&"

 

}

 

 

add variable and value to newquery

 

append newquery [lindex $params 0] "=" [lindex $params 1]

 

}

 

}

 

log local0. "new query string $newquery"

 

 

rebuild new uri with path and query string

 

set newuri [HTTP::path]

 

append newuri "?" $newquery

 

log local0. "new uri: $newuri"

 

 

set the uri request to the new one

 

HTTP::uri $newuri

 

log local0. "new HTTP::uri: [HTTP::uri]"

 

log local0. "--------------------------"

 

}

 

}

 

----------------------------------------------------------------------------

 

 

Example logs:

 

-----------------------------------------------------------------------------

 

Mar 13 12:59:20 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : HTTP::uri: /cp/wu/as?getAlertMessage=true&_=1205438360315

 

Mar 13 12:59:20 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : HTTP::query: getAlertMessage=true&_=1205438360315

 

Mar 13 12:59:20 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : new query string getAlertMessage=true

 

Mar 13 12:59:20 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : new uri: /cp/wu/as?getAlertMessage=true

 

Mar 13 12:59:20 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : new HTTP::uri: /cp/wu/as?getAlertMessage=true&_=1205438360315

 

Mar 13 12:59:20 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : --------------------------

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : --------------------------

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : HTTP::uri: /cp/wu/as?getAlertMessage=true&_=1205438710749

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : HTTP::query: getAlertMessage=true&_=1205438710749

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : new query string getAlertMessage=true

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : new uri: /cp/wu/as?getAlertMessage=true

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : new HTTP::uri: /cp/wu/as?getAlertMessage=true&_=1205438710749

 

Mar 13 13:05:10 tmm tmm[1034]: Rule dev.usource.uvic.ca_strip_query_variable : --------------------------

 

 

 

The iRule line that is NOT working seems to be:

 

 

HTTP::uri $newuri

 

 

 

What is not correct about that?

 

 

Thanks

 

 

Scott Campbell