Add queryOptions.Inreval that may be used by interval/range vars (#1957)

* Add query options Inreval to that may be used by interval/range vars

* Extend grafana interval validation; fix row.Collapsed option usage

Author: chudilka1

observability-lib/grafana/builder.go

@@ -80,9 +80,7 @@ func (b *Builder) AddVars(items ...cog.Builder[dashboard.VariableModel]) {
 func (b *Builder) AddRow(title string, options ...RowOptions) {
 	row := dashboard.NewRowBuilder(title)
 	for _, o := range options {
-		if o.Collapsed {
-			row.Collapsed(true)
-		}
+		row.Collapsed(o.Collapsed)
 	}
 	b.dashboardBuilder.WithRow(row)
 }

observability-lib/grafana/panels.go

@@ -1,6 +1,9 @@
 package grafana
 
 import (
+	"regexp"
+	"strconv"
+
 	"github.com/grafana/grafana-foundation-sdk/go/alerting"
 	"github.com/grafana/grafana-foundation-sdk/go/bargauge"
 	"github.com/grafana/grafana-foundation-sdk/go/cog"
@@ -29,6 +32,7 @@ const (
 type Query struct {
 	Expr      string
 	Legend    string
+	Interval  string // i.e. 30s, 2m, a lower limit for the interval that will be sent to datasource and used by $__interval/range variables
 	Instant   bool
 	Min       float64
 	Format    prometheus.PromQueryFormat
@@ -41,6 +45,10 @@ func newQuery(query Query) *prometheus.DataqueryBuilder {
 		LegendFormat(query.Legend).
 		Format(query.Format)
 
+	if isValidDuration(query.Interval) {
+		res.Interval(query.Interval)
+	}
+
 	if query.Instant {
 		res.Instant()
 	}
@@ -51,6 +59,16 @@ func newQuery(query Query) *prometheus.DataqueryBuilder {
 	return res
 }
 
+func isValidDuration(interval string) bool {
+	var grafanaDurationRegexp = regexp.MustCompile(`^(\d+)(ms|[smhdwMy])$`) // ms, s, m, h, d, w, M, y
+	m := grafanaDurationRegexp.FindStringSubmatch(interval)
+	if m == nil {
+		return false
+	}
+	n, _ := strconv.ParseInt(m[1], 10, 64)
+	return n > 0
+}
+
 type LegendOptions struct {
 	Placement   common.LegendPlacement
 	DisplayMode common.LegendDisplayMode