mixin-utils: add sum_by parameters to ncHistogramAverageRate (#1554)

Author: juliusmh

mixin-utils/test/test_native-classic-histogram.libsonnet

@@ -116,6 +116,16 @@ test.new(std.thisFile)
     },
   )
 )
++ test.case.new(
+  name='rate of average with sum_by labels',
+  test=test.expect.eq(
+    actual=utils.ncHistogramAverageRate('request_duration_seconds', 'cluster="cluster1", job="job1"', sum_by=['namespace']),
+    expected={
+      classic: 'sum by (namespace) (rate(request_duration_seconds_sum{cluster="cluster1", job="job1"}[$__rate_interval])) /\nsum by (namespace) (rate(request_duration_seconds_count{cluster="cluster1", job="job1"}[$__rate_interval]))\n',
+      native: 'sum by (namespace) (histogram_sum(rate(request_duration_seconds{cluster="cluster1", job="job1"}[$__rate_interval]))) /\nsum by (namespace) (histogram_count(rate(request_duration_seconds{cluster="cluster1", job="job1"}[$__rate_interval])))\n',
+    },
+  )
+)
 + test.case.new(
   name='rate of average in recording rule with different interval, multiplier',
   test=test.expect.eq(

mixin-utils/utils.libsonnet

@@ -100,24 +100,27 @@ local g = import 'grafana-builder/grafana.libsonnet';
   // classic histograms.
   // If from_recording is true, the function will assume :sum_rate metric
   // suffix and no rate needed.
-  ncHistogramAverageRate(metric, selector, rate_interval='$__rate_interval', multiplier='', from_recording=false)::
+  ncHistogramAverageRate(metric, selector, rate_interval='$__rate_interval', multiplier='', from_recording=false, sum_by=[])::
+    local sumBy = if std.length(sum_by) > 0 then ' by (%s) ' % std.join(', ', sum_by) else '';
     local multiplierStr = if multiplier == '' then '' else '%s * ' % multiplier;
     {
       classic: |||
-        %(multiplier)ssum(%(sumMetricQuery)s) /
-        sum(%(countMetricQuery)s)
+        %(multiplier)ssum%(sumBy)s(%(sumMetricQuery)s) /
+        sum%(sumBy)s(%(countMetricQuery)s)
       ||| % {
         sumMetricQuery: $.ncHistogramSumRate(metric, selector, rate_interval, from_recording).classic,
         countMetricQuery: $.ncHistogramCountRate(metric, selector, rate_interval, from_recording).classic,
         multiplier: multiplierStr,
+        sumBy: sumBy,
       },
       native: |||
-        %(multiplier)ssum(%(sumMetricQuery)s) /
-        sum(%(countMetricQuery)s)
+        %(multiplier)ssum%(sumBy)s(%(sumMetricQuery)s) /
+        sum%(sumBy)s(%(countMetricQuery)s)
       ||| % {
         sumMetricQuery: $.ncHistogramSumRate(metric, selector, rate_interval, from_recording).native,
         countMetricQuery: $.ncHistogramCountRate(metric, selector, rate_interval, from_recording).native,
         multiplier: multiplierStr,
+        sumBy: sumBy,
       },
     },