Fix persistence of rulegroup evaluation delay.

CHANGELOG.md

@@ -27,6 +27,7 @@
 * [BUGFIX] Flusher: Add `Overrides` as a dependency to prevent panics when starting with `-target=flusher`. #3151
 * [BUGFIX] Updated `golang.org/x/text` dependency to fix CVE-2022-32149. #3285
 * [BUGFIX] Query-frontend: properly close gRPC streams to the query-scheduler to stop memory and goroutines leak. #3302
+* [BUGFIX] Ruler: persist evaluation delay configured in the rulegroup. #3392
 
 ### Mixin
 

pkg/ruler/rulespb/compat.go

@@ -26,6 +26,9 @@ func ToProto(user string, namespace string, rl rulefmt.RuleGroup) *RuleGroupDesc
 		User:          user,
 		SourceTenants: rl.SourceTenants,
 	}
+	if rl.EvaluationDelay != nil && *rl.EvaluationDelay > 0 {
+		rg.EvaluationDelay = time.Duration(*rl.EvaluationDelay)
+	}
 	return &rg
 }
 
@@ -53,6 +56,10 @@ func FromProto(rg *RuleGroupDesc) rulefmt.RuleGroup {
 		Rules:         make([]rulefmt.RuleNode, len(rg.GetRules())),
 		SourceTenants: rg.GetSourceTenants(),
 	}
+	if rg.EvaluationDelay > 0 {
+		formattedRuleGroup.EvaluationDelay = new(model.Duration)
+		*formattedRuleGroup.EvaluationDelay = model.Duration(rg.EvaluationDelay)
+	}
 
 	for i, rl := range rg.GetRules() {
 		exprNode := yaml.Node{}

pkg/ruler/rulespb/compat_test.go

@@ -0,0 +1,74 @@
+package rulespb
+
+import (
+	"testing"
+
+	"github.com/prometheus/prometheus/model/rulefmt"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
+)
+
+func TestRoundtrip(t *testing.T) {
+	for name, group := range map[string]string{
+		"no eval delay": `
+name: testrules
+rules:
+    - record: test_metric:sum:rate1m
+      expr: sum(rate(test_metric[1m]))
+
+    - alert: ThisIsBad
+      expr: sum(rate(test_metric[2m]))
+      for: 10m
+`,
+
+		"with eval delay": `
+name: testrules
+evaluation_delay: 3m
+rules:
+    - record: test_metric:sum:rate1m
+      expr: sum(rate(test_metric[1m]))
+`,
+
+		"with eval delay and source tenants": `
+name: testrules
+evaluation_delay: 3m
+source_tenants:
+  - a
+  - b
+rules:
+    - record: test_metric:sum:rate1m
+      expr: sum(rate(test_metric[1m]))
+`,
+	} {
+		t.Run(name, func(t *testing.T) {
+			rg := rulefmt.RuleGroup{}
+			require.NoError(t, yaml.Unmarshal([]byte(group), &rg))
+
+			desc := ToProto("user", "namespace", rg)
+			newRg := FromProto(desc)
+
+			newYaml, err := yaml.Marshal(newRg)
+			require.NoError(t, err)
+
+			assert.YAMLEq(t, group, string(newYaml))
+		})
+	}
+}
+
+func TestZeroEvalDelayIsIgnored(t *testing.T) {
+	const group = `
+name: testrules
+evaluation_delay: 0s
+rules:
+    - record: test_metric:sum:rate1m
+      expr: sum(rate(test_metric[1m]))
+`
+	rg := rulefmt.RuleGroup{}
+	require.NoError(t, yaml.Unmarshal([]byte(group), &rg))
+
+	desc := ToProto("user", "namespace", rg)
+	newRg := FromProto(desc)
+
+	assert.Nil(t, newRg.EvaluationDelay)
+}