I use macro to define core calculations. And I'd like to have as less params to define for the macro as possible. So, I have a macro that base it's calculations on the variable $period. Then I try to use a variable that related to period in the graphite query, but I receive an error.
Simplified code:
# defined outside a macro
$period_min = 5
#macro, skipping irrelevant variables
$control_period_min = $period_min * 3
$periods = graphiteBand( $expr, "${control_period_min}m", "1h", "tag", 1 )
Produces:
graphiteBand: time: unknown unit * in duration 5 * 3m
I wonder, is it possible to implement the same logic different way?
Variables are just string replacement. Since you have put it in quotes, you are making a string that would be literally "5 * 3".
What you can do is use the tod() function:
# defined outside a macro
$period_min = 5
#macro, skipping irrelevant variables
$control_period_min = $period_min * 3
avg(q("avg:rate:os.cpu{host=*bosun*}", tod($control_period_min), ""))