add threshold alerting based on dynamic configuration

Author: Yengas

mocks/add_metrics.go

@@ -23,5 +23,8 @@ type Static struct {
 }
 
 type Dynamic struct {
-	Test string
+	Threshold struct {
+		Min float64
+		Max float64
+	}
 }

pkg/config/config.go

@@ -5,6 +5,7 @@ import (
 	"github.com/fsnotify/fsnotify"
 	"github.com/prometheus/common/log"
 	"github.com/spf13/viper"
+	"iot-demo/pkg/metrics/alert"
 	"sync"
 )
 
@@ -15,8 +16,8 @@ type DynamicGetter struct {
 }
 
 
-func (dg *DynamicGetter) GetMessage() string {
-	return dg.getCurrent().Test
+func (dg *DynamicGetter) GetThreshold() alert.Threshold {
+	return dg.getCurrent().Threshold
 }
 
 func NewDynamicGetter(s Selection) (*DynamicGetter, error) {

pkg/config/dynamic.go

@@ -1,6 +1,6 @@
 // GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
 // This file was generated by swaggo/swag at
-// 2020-02-21 08:47:45.733339 +0300 +03 m=+3.843943819
+// 2020-02-21 11:58:17.562006 +0300 +03 m=+3.916537146
 
 package docs
 

pkg/http/docs/docs.go

@@ -1,31 +1,48 @@
 package add_metrics
 
 import (
+	"iot-demo/pkg/metrics/alert"
 	"iot-demo/pkg/metrics/ingestion"
 )
 
+type ResponseToken string
+const (
+	Alert ResponseToken = "ALERT"
+	Ok ResponseToken = "OK"
+)
+
 type Inserter interface {
 	Insert(deviceID int, metricsToInsert []*ingestion.DecimalMetricValue) error
 }
 
 type ConfigGetter interface {
-	GetMessage() string
+	GetThreshold() alert.Threshold
 }
 
 type Service struct {
 	inserter Inserter
-	getter   ConfigGetter
+	config   ConfigGetter
 }
 
-func (s *Service) Add(deviceID int, metricsToInsert []*ingestion.DecimalMetricValue) (string, error) {
+func (s *Service) Add(deviceID int, metricsToInsert []*ingestion.DecimalMetricValue) (ResponseToken, error) {
 	err := s.inserter.Insert(deviceID, metricsToInsert)
 	if err != nil {
 		return "", err
 	}
 
-	return s.getter.GetMessage(), nil
+	threshold := s.config.GetThreshold()
+	return getMessage(threshold, metricsToInsert), nil
+}
+
+func getMessage(threshold alert.Threshold, metrics []*ingestion.DecimalMetricValue) ResponseToken {
+	for _, metric := range metrics {
+		if threshold.DoesMatch(metric.Value) {
+			return Alert
+		}
+	}
+	return Ok
 }
 
-func NewService(inserter Inserter, getter ConfigGetter) *Service {
-	return &Service{inserter: inserter, getter: getter}
+func NewService(inserter Inserter, config ConfigGetter) *Service {
+	return &Service{inserter: inserter, config: config}
 }

pkg/metrics/add-metrics/add_metrics.go

@@ -6,8 +6,10 @@ import (
 	"github.com/stretchr/testify/assert"
 	"iot-demo/mocks"
 	add_metrics "iot-demo/pkg/metrics/add-metrics"
+	"iot-demo/pkg/metrics/alert"
 	"iot-demo/pkg/metrics/ingestion"
 	"testing"
+	"time"
 )
 
 //go:generate mockgen -package mocks -destination ../../../mocks/add_metrics.go iot-demo/pkg/metrics/add-metrics Inserter,ConfigGetter
@@ -33,7 +35,7 @@ func TestAdd_Should_Fail_If_Insert_Fails(t *testing.T) {
 
 	getter.
 		EXPECT().
-		GetMessage().
+		GetThreshold().
 		Times(0)
 
 	// Act
@@ -44,13 +46,16 @@ func TestAdd_Should_Fail_If_Insert_Fails(t *testing.T) {
 	assert.Equal(t, err, expectedErr)
 }
 
-func TestAdd_Should_Succeed_And_Return_Get_Message(t *testing.T) {
+func TestAdd_Should_Succeed_And_Return_Ok(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
 
 	// Arrange
 	deviceID, metricsToInsert := 52, []*ingestion.DecimalMetricValue(nil)
-	expectedMessage := "get-message-result"
+	threshold := alert.Threshold{
+		Min: 0,
+		Max: 0,
+	}
 
 	inserter := mocks.NewMockInserter(ctrl)
 	getter := mocks.NewMockConfigGetter(ctrl)
@@ -65,14 +70,54 @@ func TestAdd_Should_Succeed_And_Return_Get_Message(t *testing.T) {
 
 	getter.
 		EXPECT().
-		GetMessage().
-		Return(expectedMessage).
+		GetThreshold().
+		Return(threshold).
 		Times(1)
 
 	// Act
 	res, err := addMetrics.Add(deviceID, metricsToInsert)
 
 	// Assert
 	assert.Nil(t, err)
-	assert.Equal(t, res, expectedMessage)
+	assert.Equal(t, res, add_metrics.Ok)
+}
+
+
+func TestAdd_Should_Alert_And_Return_Alert(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	// Arrange
+	deviceID, metricsToInsert := 52, []*ingestion.DecimalMetricValue{{
+		Value: 5,
+		Time:  ingestion.Time(time.Now()),
+	}}
+	threshold := alert.Threshold{
+		Min: 1,
+		Max: 10,
+	}
+
+	inserter := mocks.NewMockInserter(ctrl)
+	getter := mocks.NewMockConfigGetter(ctrl)
+
+	addMetrics := add_metrics.NewService(inserter, getter)
+
+	inserter.
+		EXPECT().
+		Insert(deviceID, metricsToInsert).
+		Return(nil).
+		Times(1)
+
+	getter.
+		EXPECT().
+		GetThreshold().
+		Return(threshold).
+		Times(1)
+
+	// Act
+	res, err := addMetrics.Add(deviceID, metricsToInsert)
+
+	// Assert
+	assert.Nil(t, err)
+	assert.Equal(t, res, add_metrics.Alert)
 }

pkg/metrics/add-metrics/add_metrics_test.go

@@ -0,0 +1,10 @@
+package alert
+
+type Threshold struct {
+	Min float64
+	Max float64
+}
+
+func (t *Threshold) DoesMatch(value float64) bool {
+	return value >= t.Min && value <= t.Max
+}

pkg/metrics/alert/alert.go

@@ -0,0 +1,36 @@
+package alert
+
+import "testing"
+
+func TestThreshold_DoesMatch(t1 *testing.T) {
+	type fields struct {
+		Min float64
+		Max float64
+	}
+	type args struct {
+		value float64
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		args   args
+		want   bool
+	}{
+		{"does match if min", fields{5, 10}, args{5}, true},
+		{"does match if max", fields{5, 10}, args{10}, true},
+		{"does match if between", fields{5, 10}, args{7}, true},
+		{"does not match if lesser than min", fields{5, 10}, args{4}, false},
+		{"does not match if bigger than max", fields{5, 10}, args{11}, false},
+	}
+	for _, tt := range tests {
+		t1.Run(tt.name, func(t1 *testing.T) {
+			t := &Threshold{
+				Min: tt.fields.Min,
+				Max: tt.fields.Max,
+			}
+			if got := t.DoesMatch(tt.args.value); got != tt.want {
+				t1.Errorf("DoesMatch() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

pkg/metrics/alert/alert_test.go

@@ -1 +1,3 @@
-test: 'this is dynamic'
+threshold:
+  Min: 74
+  Max: 100