feat(api): Do not allow user to save trigger with enormous TTL

Closes #190

api/dto/triggers.go

@@ -136,6 +136,10 @@ func (trigger *Trigger) Bind(request *http.Request) error {
 		return err
 	}
 
+	if err := checkTTLSanity(trigger, metricsSource); err != nil {
+		return api.ErrInvalidRequestContent{ValidationError: err}
+	}
+
 	if err := resolvePatterns(request, trigger, &triggerExpression, metricsSource); err != nil {
 		return err
 	}
@@ -146,6 +150,19 @@ func (trigger *Trigger) Bind(request *http.Request) error {
 	return nil
 }
 
+func checkTTLSanity(trigger *Trigger, metricsSource metricSource.MetricSource) error {
+	maximumAllowedTTL := metricsSource.GetMetricsTTLSeconds()
+
+	if trigger.TTL > maximumAllowedTTL {
+		triggerType := "local"
+		if trigger.IsRemote {
+			triggerType = "remote"
+		}
+		return fmt.Errorf("TTL for %s trigger can't be more than %d seconds", triggerType, maximumAllowedTTL)
+	}
+	return nil
+}
+
 func resolvePatterns(request *http.Request, trigger *Trigger, expressionValues *expression.TriggerExpression, metricsSource metricSource.MetricSource) error {
 	now := time.Now().Unix()
 	targetNum := 1

api/dto/triggers_test.go

@@ -28,6 +28,7 @@ func TestExpressionModeMultipleTargetsWarnValue(t *testing.T) {
 		sourceProvider := metricSource.CreateMetricSourceProvider(localSource, remoteSource)
 
 		localSource.EXPECT().IsConfigured().Return(true, nil).AnyTimes()
+		localSource.EXPECT().GetMetricsTTLSeconds().Return(int64(3600)).AnyTimes()
 		localSource.EXPECT().Fetch(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Return(fetchResult, nil).AnyTimes()
 		fetchResult.EXPECT().GetPatterns().Return(make([]string, 0), nil).AnyTimes()
 		fetchResult.EXPECT().GetMetricsData().Return([]*metricSource.MetricData{metricSource.MakeMetricData("", []float64{}, 0, 0)}).AnyTimes()

metric_source/local/local.go

@@ -106,6 +106,11 @@ func (local *Local) Fetch(target string, from int64, until int64, allowRealTimeA
 	return result, nil
 }
 
+// GetMetricsTTLSeconds returns metrics lifetime in Redis
+func (local *Local) GetMetricsTTLSeconds() int64 {
+	return local.dataBase.GetMetricsTTLSeconds()
+}
+
 // IsConfigured always returns true. It easy to configure local source =)
 func (local *Local) IsConfigured() (bool, error) {
 	return true, nil

metric_source/remote/remote.go

@@ -68,6 +68,11 @@ func (remote *Remote) Fetch(target string, from, until int64, allowRealTimeAlert
 	return &fetchResult, nil
 }
 
+// GetMetricsTTLSeconds returns maximum time interval that we are allowed to fetch from remote
+func (remote *Remote) GetMetricsTTLSeconds() int64 {
+	return int64(remote.config.MetricsTTL.Seconds())
+}
+
 // IsConfigured returns false in cases that user does not properly configure remote settings like graphite URL
 func (remote *Remote) IsConfigured() (bool, error) {
 	if remote.config.isEnabled() {

metric_source/source.go

@@ -3,6 +3,7 @@ package metricSource
 // MetricSource implements graphite metrics source abstraction
 type MetricSource interface {
 	Fetch(target string, from int64, until int64, allowRealTimeAlerting bool) (FetchResult, error)
+	GetMetricsTTLSeconds() int64
 	IsConfigured() (bool, error)
 }