Rule: Support ruleGroup limit

CHANGELOG.md

@@ -27,6 +27,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#4847](https://github.com/thanos-io/thanos/pull/4847) Query: add `--alert.query-url` which is used in the user interface for rules/alerts pages. By default the HTTP listen address is used for this URL.
 - [#4856](https://github.com/thanos-io/thanos/pull/4856) Mixin: Add Query Frontend Grafana dashboard.
 - [#4874](https://github.com/thanos-io/thanos/pull/4874) Query: Add `--endpoint-strict` flag to statically configure Thanos API server endpoints. It is similar to `--store-strict` but supports passing any Thanos gRPC APIs: StoreAPI, MetadataAPI, RulesAPI, TargetsAPI and ExemplarsAPI.
+- [#4868](https://github.com/thanos-io/thanos/pull/4868) Rule: Support ruleGroup limit introduced by Prometheus v2.31.0.
 
 ### Fixed
 

pkg/rules/manager.go

@@ -44,6 +44,7 @@ func (g Group) toProto() *rulespb.RuleGroup {
 		Name:                    g.Name(),
 		File:                    g.OriginalFile,
 		Interval:                g.Interval().Seconds(),
+		Limit:                   int64(g.Limit()),
 		PartialResponseStrategy: g.PartialResponseStrategy,
 		// UTC needed due to https://github.com/gogo/protobuf/issues/519.
 		LastEvaluation:            g.GetLastEvaluation().UTC(),

pkg/rules/manager_test.go

@@ -16,13 +16,15 @@ import (
 	"time"
 
 	"github.com/go-kit/kit/log"
+	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/prometheus/pkg/exemplar"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/promql"
 	"github.com/prometheus/prometheus/rules"
 	"github.com/prometheus/prometheus/storage"
 	"github.com/thanos-io/thanos/pkg/extprom"
+	"github.com/thanos-io/thanos/pkg/runutil"
 	"gopkg.in/yaml.v3"
 
 	"github.com/thanos-io/thanos/pkg/store/storepb"
@@ -293,6 +295,7 @@ func TestConfigRuleAdapterUnmarshalMarshalYAML(t *testing.T) {
   - alert: some
     expr: up
   partial_response_strategy: ABORT
+  limit: 10
 - name: something2
   rules:
   - alert: some
@@ -302,7 +305,8 @@ func TestConfigRuleAdapterUnmarshalMarshalYAML(t *testing.T) {
 	b, err := yaml.Marshal(c)
 	testutil.Ok(t, err)
 	testutil.Equals(t, `groups:
-    - name: something1
+    - limit: 10
+      name: something1
       rules:
         - alert: some
           expr: up
@@ -383,9 +387,7 @@ groups:
 	// We need to run the underlying rule managers to update them more than
 	// once (otherwise there's a deadlock).
 	thanosRuleMgr.Run()
-	defer func() {
-		thanosRuleMgr.Stop()
-	}()
+	t.Cleanup(thanosRuleMgr.Stop)
 
 	err = thanosRuleMgr.Update(1*time.Second, []string{
 		filepath.Join(dir, "no_strategy.yaml"),
@@ -397,3 +399,60 @@ groups:
 	testutil.Ok(t, err)
 	testutil.Equals(t, 0, len(thanosRuleMgr.RuleGroups()))
 }
+
+func TestManagerRunRulesWithRuleGroupLimit(t *testing.T) {
+	dir, err := ioutil.TempDir("", "test_rule_rule_groups")
+	testutil.Ok(t, err)
+	t.Cleanup(func() { testutil.Ok(t, os.RemoveAll(dir)) })
+	filename := filepath.Join(dir, "with_limit.yaml")
+	testutil.Ok(t, ioutil.WriteFile(filename, []byte(`
+groups:
+- name: "something1"
+  interval: 1ms
+  limit: 1
+  rules:
+  - alert: "some"
+    expr: "up>0"
+    for: 0s
+`), os.ModePerm))
+
+	thanosRuleMgr := NewManager(
+		context.Background(),
+		nil,
+		dir,
+		rules.ManagerOptions{
+			Logger:    log.NewLogfmtLogger(os.Stderr),
+			Queryable: nopQueryable{},
+		},
+		func(partialResponseStrategy storepb.PartialResponseStrategy) rules.QueryFunc {
+			return func(ctx context.Context, q string, ts time.Time) (promql.Vector, error) {
+				return []promql.Sample{
+					{
+						Point:  promql.Point{T: 0, V: 1},
+						Metric: labels.FromStrings("foo", "bar"),
+					},
+					{
+						Point:  promql.Point{T: 0, V: 1},
+						Metric: labels.FromStrings("foo1", "bar1"),
+					},
+				}, nil
+			}
+		},
+		nil,
+		"http://localhost",
+	)
+	thanosRuleMgr.Run()
+	t.Cleanup(thanosRuleMgr.Stop)
+	testutil.Ok(t, thanosRuleMgr.Update(time.Millisecond, []string{filename}))
+	testutil.Equals(t, 1, len(thanosRuleMgr.protoRuleGroups()))
+	testutil.Equals(t, 1, len(thanosRuleMgr.protoRuleGroups()[0].Rules))
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	testutil.Ok(t, runutil.Retry(time.Millisecond, ctx.Done(), func() error {
+		if thanosRuleMgr.protoRuleGroups()[0].Rules[0].GetAlert().Health != string(rules.HealthBad) {
+			return errors.New("expect HealthBad")
+		}
+		return nil
+	}))
+	testutil.Equals(t, "exceeded limit of 1 with 2 alerts", thanosRuleMgr.protoRuleGroups()[0].Rules[0].GetAlert().LastError)
+}

pkg/rules/rulespb/custom_test.go

@@ -57,6 +57,7 @@ func TestJSONUnmarshalMarshal(t *testing.T) {
 						Interval:                  2442,
 						LastEvaluation:            now,
 						EvaluationDurationSeconds: 2.1,
+						Limit:                     0,
 						PartialResponseStrategy:   storepb.PartialResponseStrategy_ABORT,
 						Rules:                     []*Rule{},
 					},
@@ -78,7 +79,7 @@ func TestJSONUnmarshalMarshal(t *testing.T) {
 				},
 			},
 			// Different than input due to default enum fields.
-			expectedJSONOutput: `{"groups":[{"name":"","file":"","rules":[],"interval":0,"evaluationTime":0,"lastEvaluation":"0001-01-01T00:00:00Z","partialResponseStrategy":"ABORT"}]}`,
+			expectedJSONOutput: `{"groups":[{"name":"","file":"","rules":[],"interval":0,"evaluationTime":0,"lastEvaluation":"0001-01-01T00:00:00Z","limit":0,"partialResponseStrategy":"ABORT"}]}`,
 		},
 		{
 			name: "one valid group, with 1 with no rule type",
@@ -230,7 +231,7 @@ func TestJSONUnmarshalMarshal(t *testing.T) {
 				},
 			},
 			// Different than input due to the alerts slice being initialized to a zero-length slice instead of nil.
-			expectedJSONOutput: `{"groups":[{"name":"group1","file":"file1.yml","rules":[{"state":"pending","name":"alert1","query":"up == 0","duration":60,"labels":{"a2":"b2","c2":"d2"},"annotations":{"ann1":"ann44","ann2":"ann33"},"alerts":[],"health":"health2","lastError":"1","evaluationTime":1.1,"lastEvaluation":"0001-01-01T00:00:00Z","type":"alerting"}],"interval":2442,"evaluationTime":2.1,"lastEvaluation":"0001-01-01T00:00:00Z","partialResponseStrategy":"ABORT"}]}`,
+			expectedJSONOutput: `{"groups":[{"name":"group1","file":"file1.yml","rules":[{"state":"pending","name":"alert1","query":"up == 0","duration":60,"labels":{"a2":"b2","c2":"d2"},"annotations":{"ann1":"ann44","ann2":"ann33"},"alerts":[],"health":"health2","lastError":"1","evaluationTime":1.1,"lastEvaluation":"0001-01-01T00:00:00Z","type":"alerting"}],"interval":2442,"evaluationTime":2.1,"lastEvaluation":"0001-01-01T00:00:00Z","limit":0,"partialResponseStrategy":"ABORT"}]}`,
 		},
 		{
 			name: "one valid group, with 1 rule and alert each and second empty group.",