Forum Discussion
CumulonimbusIrule Environment Variables: Any?
What environment variables are provided for irule? I have tried a couple of ways but could not see any. I'd like to know the hostname through a low-cost method.
2 Replies
THiNimbostratus
See -tcl_platform - A variable that contains platform specific information
The hostname can be retrieved with
static::tcl_platform(machine)Returns the hostname of the BIG-IP
- THi
Did you get this working? I needed to implement pool selection based on active unit hostname and tested it now, but got stuck, as the static::tcl_platform variable wasn't working. There seems to be a bug on 11.4.0 and newer. There is a one line iRule workaround for it which needs to be used in RULE_INIT event.See sol14544: The tcl_platform iRules variable is not in the static:: namespace.
However I found another way of getting the hostname, using [info hostname] TCL-function. Tested and it works like a charm. Use it in RULE_INIT event to assign the retrieved hostname value to a static variable, which can be used in other events/iRules later. For example:
set static::host [info hostname]
