Prometheus: Add $__rate_interval_ms to go along with $__interval_ms (#69582)

* Add $__rate_interval_ms to go along with $__interval_ms

Fixes https://github.com/grafana/grafana/issues/69581

* update doc

* PoC add rate_interval_ms as rate range in prometheus

* Revert "PoC add rate_interval_ms as rate range in prometheus"

This reverts commit 7d4ec700d7.

* Update docs/sources/dashboards/variables/add-template-variables/index.md

grammar nit

Co-authored-by: Isabel <76437239+imatwawana@users.noreply.github.com>

* Update docs/sources/dashboards/variables/add-template-variables/index.md

---------

Co-authored-by: Galen <galen.kistler@grafana.com>
Co-authored-by: Isabel <76437239+imatwawana@users.noreply.github.com>
Co-authored-by: ismail simsek <ismailsimsek09@gmail.com>

docs/sources/dashboards/variables/add-template-variables/index.md

@@ -325,6 +325,10 @@ Currently only supported for Prometheus and Loki data sources. This variable rep
 
 Currently only supported for Prometheus data sources. The `$__rate_interval` variable is meant to be used in the rate function. Refer to [Prometheus query variables]({{< relref "../../../datasources/prometheus/template-variables#use-__rate_interval" >}}) for details.
 
+### $\_\_rate_interval_ms
+
+This variable is the `$__rate_interval` variable in milliseconds, not a time-interval-formatted string. For example, if the `$__rate_interval` is `20m` then the `$__rate_interval_ms` is `1200000`.
+
 ### $timeFilter or $\_\_timeFilter
 
 The `$timeFilter` variable returns the currently selected time range as an expression. For example, the time range interval `Last 7 days` expression is `time > now() - 7d`.

pkg/tsdb/prometheus/models/query.go

@@ -14,23 +14,25 @@ import (
 
 // Internal interval and range variables
 const (
-	varInterval     = "$__interval"
-	varIntervalMs   = "$__interval_ms"
-	varRange        = "$__range"
-	varRangeS       = "$__range_s"
-	varRangeMs      = "$__range_ms"
-	varRateInterval = "$__rate_interval"
+	varInterval       = "$__interval"
+	varIntervalMs     = "$__interval_ms"
+	varRange          = "$__range"
+	varRangeS         = "$__range_s"
+	varRangeMs        = "$__range_ms"
+	varRateInterval   = "$__rate_interval"
+	varRateIntervalMs = "$__rate_interval_ms"
 )
 
 // Internal interval and range variables with {} syntax
 // Repetitive code, we should have functionality to unify these
 const (
-	varIntervalAlt     = "${__interval}"
-	varIntervalMsAlt   = "${__interval_ms}"
-	varRangeAlt        = "${__range}"
-	varRangeSAlt       = "${__range_s}"
-	varRangeMsAlt      = "${__range_ms}"
-	varRateIntervalAlt = "${__rate_interval}"
+	varIntervalAlt       = "${__interval}"
+	varIntervalMsAlt     = "${__interval_ms}"
+	varRangeAlt          = "${__range}"
+	varRangeSAlt         = "${__range_s}"
+	varRangeMsAlt        = "${__range_ms}"
+	varRateIntervalAlt   = "${__rate_interval}"
+	varRateIntervalMsAlt = "${__rate_interval_ms}"
 )
 
 type TimeSeriesQueryType string
@@ -227,6 +229,7 @@ func interpolateVariables(expr, queryInterval string, interval time.Duration,
 	expr = strings.ReplaceAll(expr, varRangeMs, strconv.FormatInt(rangeMs, 10))
 	expr = strings.ReplaceAll(expr, varRangeS, strconv.FormatInt(rangeSRounded, 10))
 	expr = strings.ReplaceAll(expr, varRange, strconv.FormatInt(rangeSRounded, 10)+"s")
+	expr = strings.ReplaceAll(expr, varRateIntervalMs, strconv.FormatInt(int64(rateInterval/time.Millisecond), 10))
 	expr = strings.ReplaceAll(expr, varRateInterval, rateInterval.String())
 
 	// Repetitive code, we should have functionality to unify these
@@ -235,16 +238,17 @@ func interpolateVariables(expr, queryInterval string, interval time.Duration,
 	expr = strings.ReplaceAll(expr, varRangeMsAlt, strconv.FormatInt(rangeMs, 10))
 	expr = strings.ReplaceAll(expr, varRangeSAlt, strconv.FormatInt(rangeSRounded, 10))
 	expr = strings.ReplaceAll(expr, varRangeAlt, strconv.FormatInt(rangeSRounded, 10)+"s")
+	expr = strings.ReplaceAll(expr, varRateIntervalMsAlt, strconv.FormatInt(int64(rateInterval/time.Millisecond), 10))
 	expr = strings.ReplaceAll(expr, varRateIntervalAlt, rateInterval.String())
 	return expr
 }
 
 func isVariableInterval(interval string) bool {
-	if interval == varInterval || interval == varIntervalMs || interval == varRateInterval {
+	if interval == varInterval || interval == varIntervalMs || interval == varRateInterval || interval == varRateIntervalMs {
 		return true
 	}
 	// Repetitive code, we should have functionality to unify these
-	if interval == varIntervalAlt || interval == varIntervalMsAlt || interval == varRateIntervalAlt {
+	if interval == varIntervalAlt || interval == varIntervalMsAlt || interval == varRateIntervalAlt || interval == varRateIntervalMsAlt {
 		return true
 	}
 	return false

pkg/tsdb/prometheus/models/query_test.go

@@ -385,6 +385,60 @@ func TestParse(t *testing.T) {
 		require.Equal(t, 1*time.Minute, res.Step)
 	})
 
+	t.Run("parsing query model with $__rate_interval_ms variable", func(t *testing.T) {
+		timeRange := backend.TimeRange{
+			From: now,
+			To:   now.Add(48 * time.Hour),
+		}
+
+		q := queryContext(`{
+			"expr": "rate(ALERTS{job=\"test\" [$__rate_interval_ms]})",
+			"format": "time_series",
+			"intervalFactor": 1,
+			"refId": "A"
+		}`, timeRange)
+
+		res, err := models.Parse(q, "15s", intervalCalculator, false)
+		require.NoError(t, err)
+		require.Equal(t, "rate(ALERTS{job=\"test\" [135000]})", res.Expr)
+	})
+
+	t.Run("parsing query model with $__rate_interval_ms and $__rate_interval variable", func(t *testing.T) {
+		timeRange := backend.TimeRange{
+			From: now,
+			To:   now.Add(48 * time.Hour),
+		}
+
+		q := queryContext(`{
+			"expr": "rate(ALERTS{job=\"test\" [$__rate_interval_ms]}) + rate(ALERTS{job=\"test\" [$__rate_interval]})",
+			"format": "time_series",
+			"intervalFactor": 1,
+			"refId": "A"
+		}`, timeRange)
+
+		res, err := models.Parse(q, "15s", intervalCalculator, false)
+		require.NoError(t, err)
+		require.Equal(t, "rate(ALERTS{job=\"test\" [135000]}) + rate(ALERTS{job=\"test\" [2m15s]})", res.Expr)
+	})
+
+	t.Run("parsing query model with ${__rate_interval_ms} and ${__rate_interval} variable", func(t *testing.T) {
+		timeRange := backend.TimeRange{
+			From: now,
+			To:   now.Add(48 * time.Hour),
+		}
+
+		q := queryContext(`{
+			"expr": "rate(ALERTS{job=\"test\" [${__rate_interval_ms}]}) + rate(ALERTS{job=\"test\" [${__rate_interval}]})",
+			"format": "time_series",
+			"intervalFactor": 1,
+			"refId": "A"
+		}`, timeRange)
+
+		res, err := models.Parse(q, "15s", intervalCalculator, false)
+		require.NoError(t, err)
+		require.Equal(t, "rate(ALERTS{job=\"test\" [135000]}) + rate(ALERTS{job=\"test\" [2m15s]})", res.Expr)
+	})
+
 	t.Run("parsing query model of range query", func(t *testing.T) {
 		timeRange := backend.TimeRange{
 			From: now,