Forum Discussion
NimbostratusHelp with irule structure
Hi sirs,
I just wrote a rule that reads a specific HTTP header and saves it to USER_COD and if it has an empty value or PRINT value it should forward the connection to a certain pool, if the this value is a specific number (can be like 1-999), this number should be compared against numbers that are inside the datagroups and if there is a match the connection will be forwarded to the correct pool, if no value is available in the datagroups to compare against, the default pool will be chosen. Unfortunately I am not a great expert in programming (as you guys can see) and during the tests I got several errors in variables reading, I believe that error is related to the irule structure when try to save the value (when receiving PRINT or empty) and when the value is compared to the datagroup, I really need a help with the experts guys that live here hehe
when RULE_INIT {
# 0 - log off
# 1 - log on
set static::debug_user_cod 0
}
when HTTP_REQUEST {
# checks if the USER_COD is empty or PRINT
if {[HTTP::header value "USER_COD"] equals "" or "PRINT" } {
# save it on USER_COD_NULL
set USER_COD_NULL [HTTP::header value "USER_COD"]
# forward to pool_default
pool POOL_DEFAULT
# show log
if { $static::debug_user_cod } { log local0. "src: [IP::client_addr] get USER_COD: $USER_COD - send it to default pool" }
# If USER_COD contains numbers save it on USER_COD to compare with DGs
} else { set USER_COD [HTTP::header value "USER_COD"] }
# show log
if { $static::debug_user_cod } {
set HTTP_DEBUG_COD "src: [IP::client_addr] URL -> [HTTP::host][HTTP::uri]"
log local0. "----------------------------------------"
log local0. "$HTTP_DEBUG_COD (REQUEST)"
log local0. "Value get on USER_COD: $USER_COD"
log local0. "----------------------------------------"
}
# Compare the number saved on USER_COD with DGs to forward for the specific pool
if { $USER_COD == $DG_01 } {
pool POOL_DG_01
} elseif { $USER_COD == $DG_02 } {
pool POOL_DG_02
} elseif { $USER_COD == $DG_03 } {
pool POOL_DG_03
} elseif { $USER_COD == $DG_04 } {
pool POOL_DG_04
} elseif { $USER_COD == $DG_05 } {
pool POOL_DG_05
} elseif { $USER_COD == $DG_06 } {
pool POOL_DG_06
} elseif { $USER_COD == $DG_07 } {
pool POOL_DG_07
# If no values match forward it to default one
} else { pool POOL_DEFAULT }
}
when SERVER_CONNECTED {
if { $static::debug_user_cod } {
log local0. "----------------------------------------"
log local0. "src: [IP::local_addr] - Dst Member: [IP::remote_addr] - USER_COD: $USER_COD"
log local0. "----------------------------------------"
}
}Erros that I got during the tests (a lot of them):
TCL error: /Common/test_log <HTTP_REQUEST> - invalid command name "894" while executing "$USER_COD"
test_log <HTTP_REQUEST> - can't read "USER_COD": no such variable while executing "if {[HTTP::header value "USER_COD"] equals "" or "PRINT" }"") }
Looking for a help from you guys... and thanks for everyone who is available to read my post.
5 Replies
iaineNacreous
Hi
Try something like this...
when RULE_INIT { # 0 - log off # 1 - log on set static::debug_user_cod 0 } when HTTP_REQUEST { if { $static::debug_user_cod } { set USER_COD [HTTP::header value "USER_COD"] } #Switch through the values of header USER_COD. If a value matches then send to appropiate pool #if no value matches,including value PRINT or a null value then send to default pool switch -glob [string tolower [HTTP::header value "USER_COD"]] { "dg_01" {pool POOL_DG_01} "dg_02" {pool POOL_DG_02} "dg_03" {pool POOL_DG_03} "dg_04" {pool POOL_DG_04} "dg_05" {pool POOL_DG_05} "dg_06" {pool POOL_DG_06} "dg_07" {pool POOL_DG_07} default {pool POOL_DEFAULT if { $static::debug_user_cod } { log local0. "----------------------------------------" log local0. "src: [IP::client_addr] URL -> [HTTP::host][HTTP::uri] (REQUEST)" log local0. "Value get on USER_COD: $USER_COD" log local0. "----------------------------------------" } } } } when SERVER_CONNECTED { if { $static::debug_user_cod } { log local0. "----------------------------------------" log local0. "src: [IP::local_addr] - Dst Member: [IP::remote_addr] - USER_COD: $USER_COD" log local0. "----------------------------------------" } }
GuilhermeHi iaine,
Thank you! I cant test right now but I still with a doubt.. how can I insert the empty value into to the datagroup ? There is some situations that header comes empty or with PRINT value and It must be send to a specific pool, may I use the default condition ?
- iaine
Hi
If the header value is null then this should get picked up by the default logic at the end of the code and sent to the default_pool.
The code is written so that is there is a match on a dg_## value in the header then the request will get sent to the corresponding pool. All other requests (ie non-matching) will get sent to the default_pool
- Guilherme
OK I got you! Im wondering how the switch will call values in the datagroup, it doesnt need to use the "class" match command ?
- iaine
hi
so if you wanted to use a data group, then the code would look something like...
when HTTP_REQUEST { set app_pool [class match -value -- [HTTP::header value "USER_COD"] eq cod_value] if {$app_pool ne ""} { pool $app_pool } else { pool default_pool } }...where cod_value is the name of the data group
ltm data-group internal /Common/cod_value {
records {
DG_01 {
data Pool_01
}
}
type string
}