Alerting: Schedule a shim implementation for recording rules (#87939)

* Add shim rule implementation for recording rules

* Give ruleFactory access to the original rule definition

* Schedule shim implementation if the rule is a recording rule

* Fix or suppress linter

* Fix nolint

pkg/services/ngalert/schedule/alert_rule.go

@@ -36,10 +36,10 @@ type Rule interface {
 	Update(lastVersion RuleVersionAndPauseStatus) bool
 }
 
-type ruleFactoryFunc func(context.Context) Rule
+type ruleFactoryFunc func(context.Context, *ngmodels.AlertRule) Rule
 
-func (f ruleFactoryFunc) new(ctx context.Context) Rule {
+func (f ruleFactoryFunc) new(ctx context.Context, rule *ngmodels.AlertRule) Rule {
-	return f(ctx)
+	return f(ctx, rule)
 }
 
 func newRuleFactory(
@@ -57,7 +57,10 @@ func newRuleFactory(
 	evalAppliedHook evalAppliedFunc,
 	stopAppliedHook stopAppliedFunc,
 ) ruleFactoryFunc {
-	return func(ctx context.Context) Rule {
+	return func(ctx context.Context, rule *ngmodels.AlertRule) Rule {
+		if rule.IsRecordingRule() {
+			return newRecordingRule(ctx, logger)
+		}
 		return newAlertRule(
 			ctx,
 			appURL,

pkg/services/ngalert/schedule/alert_rule_test.go

@@ -279,7 +279,7 @@ func TestRuleRoutine(t *testing.T) {
 			factory := ruleFactoryFromScheduler(sch)
 			ctx, cancel := context.WithCancel(context.Background())
 			t.Cleanup(cancel)
-			ruleInfo := factory.new(ctx)
+			ruleInfo := factory.new(ctx, rule)
 			go func() {
 				_ = ruleInfo.Run(rule.GetKey())
 			}()
@@ -442,7 +442,7 @@ func TestRuleRoutine(t *testing.T) {
 
 			factory := ruleFactoryFromScheduler(sch)
 			ctx, cancel := context.WithCancel(context.Background())
-			ruleInfo := factory.new(ctx)
+			ruleInfo := factory.new(ctx, rule)
 			go func() {
 				err := ruleInfo.Run(models.AlertRuleKey{})
 				stoppedChan <- err
@@ -462,7 +462,7 @@ func TestRuleRoutine(t *testing.T) {
 			require.NotEmpty(t, sch.stateManager.GetStatesForRuleUID(rule.OrgID, rule.UID))
 
 			factory := ruleFactoryFromScheduler(sch)
-			ruleInfo := factory.new(context.Background())
+			ruleInfo := factory.new(context.Background(), rule)
 			go func() {
 				err := ruleInfo.Run(rule.GetKey())
 				stoppedChan <- err
@@ -492,7 +492,7 @@ func TestRuleRoutine(t *testing.T) {
 		factory := ruleFactoryFromScheduler(sch)
 		ctx, cancel := context.WithCancel(context.Background())
 		t.Cleanup(cancel)
-		ruleInfo := factory.new(ctx)
+		ruleInfo := factory.new(ctx, rule)
 
 		go func() {
 			_ = ruleInfo.Run(rule.GetKey())
@@ -574,7 +574,7 @@ func TestRuleRoutine(t *testing.T) {
 		factory := ruleFactoryFromScheduler(sch)
 		ctx, cancel := context.WithCancel(context.Background())
 		t.Cleanup(cancel)
-		ruleInfo := factory.new(ctx)
+		ruleInfo := factory.new(ctx, rule)
 
 		go func() {
 			_ = ruleInfo.Run(rule.GetKey())
@@ -693,7 +693,7 @@ func TestRuleRoutine(t *testing.T) {
 			factory := ruleFactoryFromScheduler(sch)
 			ctx, cancel := context.WithCancel(context.Background())
 			t.Cleanup(cancel)
-			ruleInfo := factory.new(ctx)
+			ruleInfo := factory.new(ctx, rule)
 
 			go func() {
 				_ = ruleInfo.Run(rule.GetKey())
@@ -727,7 +727,7 @@ func TestRuleRoutine(t *testing.T) {
 		factory := ruleFactoryFromScheduler(sch)
 		ctx, cancel := context.WithCancel(context.Background())
 		t.Cleanup(cancel)
-		ruleInfo := factory.new(ctx)
+		ruleInfo := factory.new(ctx, rule)
 
 		go func() {
 			_ = ruleInfo.Run(rule.GetKey())

pkg/services/ngalert/schedule/recording_rule.go

@@ -0,0 +1,54 @@
+package schedule
+
+import (
+	context "context"
+
+	"github.com/grafana/grafana/pkg/infra/log"
+	ngmodels "github.com/grafana/grafana/pkg/services/ngalert/models"
+	"github.com/grafana/grafana/pkg/util"
+)
+
+type recordingRule struct {
+	ctx    context.Context
+	stopFn util.CancelCauseFunc
+
+	logger log.Logger
+}
+
+func newRecordingRule(parent context.Context, logger log.Logger) *recordingRule {
+	ctx, stop := util.WithCancelCause(parent)
+	return &recordingRule{
+		ctx:    ctx,
+		stopFn: stop,
+		logger: logger,
+	}
+}
+
+func (r *recordingRule) Eval(eval *Evaluation) (bool, *Evaluation) {
+	return true, nil
+}
+
+func (r *recordingRule) Update(lastVersion RuleVersionAndPauseStatus) bool {
+	return true
+}
+
+func (r *recordingRule) Stop(reason error) {
+	if r.stopFn != nil {
+		r.stopFn(reason)
+	}
+}
+
+func (r *recordingRule) Run(key ngmodels.AlertRuleKey) error {
+	ctx := ngmodels.WithRuleKey(r.ctx, key)
+	logger := r.logger.FromContext(ctx)
+	logger.Debug("Recording rule routine started")
+
+	// nolint:gosimple
+	for {
+		select {
+		case <-ctx.Done():
+			logger.Debug("Stopping recording rule routine")
+			return nil
+		}
+	}
+}

pkg/services/ngalert/schedule/registry.go

@@ -18,7 +18,7 @@ import (
 var errRuleDeleted = errors.New("rule deleted")
 
 type ruleFactory interface {
-	new(context.Context) Rule
+	new(context.Context, *models.AlertRule) Rule
 }
 
 type ruleRegistry struct {
@@ -30,15 +30,16 @@ func newRuleRegistry() ruleRegistry {
 	return ruleRegistry{rules: make(map[models.AlertRuleKey]Rule)}
 }
 
-// getOrCreate gets rule routine from registry by the key. If it does not exist, it creates a new one.
+// getOrCreate gets a rule routine from registry for the provided rule. If it does not exist, it creates a new one.
 // Returns a pointer to the rule routine and a flag that indicates whether it is a new struct or not.
-func (r *ruleRegistry) getOrCreate(context context.Context, key models.AlertRuleKey, factory ruleFactory) (Rule, bool) {
+func (r *ruleRegistry) getOrCreate(context context.Context, item *models.AlertRule, factory ruleFactory) (Rule, bool) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
+	key := item.GetKey()
 	rule, ok := r.rules[key]
 	if !ok {
-		rule = factory.new(context)
+		rule = factory.new(context, item)
 		r.rules[key] = rule
 	}
 	return rule, !ok

pkg/services/ngalert/schedule/schedule.go

@@ -253,9 +253,10 @@ func (sch *schedule) processTick(ctx context.Context, dispatcherGroup *errgroup.
 		sch.stopAppliedFunc,
 	)
 	for _, item := range alertRules {
+		ruleRoutine, newRoutine := sch.registry.getOrCreate(ctx, item, ruleFactory)
 		key := item.GetKey()
-		ruleRoutine, newRoutine := sch.registry.getOrCreate(ctx, key, ruleFactory)
 		logger := sch.log.FromContext(ctx).New(key.LogContext()...)
+
 		// enforce minimum evaluation interval
 		if item.IntervalSeconds < int64(sch.minRuleInterval.Seconds()) {
 			logger.Debug("Interval adjusted", "originalInterval", item.IntervalSeconds, "adjustedInterval", sch.minRuleInterval.Seconds())

pkg/services/ngalert/schedule/schedule_unit_test.go

@@ -405,7 +405,7 @@ func TestSchedule_deleteAlertRule(t *testing.T) {
 			ruleFactory := ruleFactoryFromScheduler(sch)
 			rule := models.RuleGen.GenerateRef()
 			key := rule.GetKey()
-			info, _ := sch.registry.getOrCreate(context.Background(), key, ruleFactory)
+			info, _ := sch.registry.getOrCreate(context.Background(), rule, ruleFactory)
 			sch.deleteAlertRule(key)
 			require.ErrorIs(t, info.(*alertRule).ctx.Err(), errRuleDeleted)
 			require.False(t, sch.registry.exists(key))