feat: Add templates to trigger description #484

* Added templates to trigger description
* Added presentation of trigger description in non-editing for api

Closed #484

api/handler/trigger.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/go-chi/chi"
 	"github.com/go-chi/render"
+	"github.com/moira-alert/moira"
 	"github.com/moira-alert/moira/metric_source/local"
 	"github.com/moira-alert/moira/metric_source/remote"
 
@@ -20,7 +21,8 @@ import (
 func trigger(router chi.Router) {
 	router.Use(middleware.TriggerContext)
 	router.Put("/", updateTrigger)
-	router.Get("/", getTrigger)
+	router.With(middleware.TriggerContext,
+		middleware.Populate(false)).Get("/", getTrigger)
 	router.Delete("/", removeTrigger)
 	router.Get("/state", getTriggerState)
 	router.Route("/throttling", func(router chi.Router) {
@@ -35,6 +37,7 @@ func trigger(router chi.Router) {
 func updateTrigger(writer http.ResponseWriter, request *http.Request) {
 	triggerID := middleware.GetTriggerID(request)
 	trigger := &dto.Trigger{}
+
 	if err := render.Bind(request, trigger); err != nil {
 		switch err := err.(type) {
 		case local.ErrParseExpr, local.ErrEvalExpr, local.ErrUnknownFunction:
@@ -50,9 +53,19 @@ func updateTrigger(writer http.ResponseWriter, request *http.Request) {
 		default:
 			render.Render(writer, request, api.ErrorInternalServer(err))
 		}
+
 		return
 	}
 
+	if trigger.Desc != nil {
+		triggerData := moira.TriggerData{Desc: *trigger.Desc, Name: trigger.Name}
+		if _, err := triggerData.GetPopulatedDescription(moira.NotificationEvents{}); err != nil {
+			render.Render(writer, request, api.ErrorRender(
+				fmt.Errorf("You have an error in your Go template: %v", err)))
+			return
+		}
+	}
+
 	timeSeriesNames := middleware.GetTimeSeriesNames(request)
 	response, err := controller.UpdateTrigger(database, &trigger.TriggerModel, triggerID, timeSeriesNames)
 	if err != nil {
@@ -84,6 +97,18 @@ func getTrigger(writer http.ResponseWriter, request *http.Request) {
 		render.Render(writer, request, err)
 		return
 	}
+
+	if needToPopulate := middleware.GetPopulated(request); needToPopulate && trigger.Desc != nil {
+		triggerData := moira.TriggerData{Desc: *trigger.Desc, Name: trigger.Name}
+
+		eventsList, err := controller.GetTriggerEvents(database, triggerID, 0, 3)
+		if err != nil {
+			render.Render(writer, request, err)
+		}
+
+		*trigger.Desc, _ = triggerData.GetPopulatedDescription(eventsList.List)
+	}
+
 	if err := render.Render(writer, request, trigger); err != nil {
 		render.Render(writer, request, api.ErrorRender(err))
 	}

api/middleware/context.go

@@ -145,6 +145,21 @@ func Pager(defaultCreatePager bool, defaultPagerID string) func(next http.Handle
 	}
 }
 
+// Populate gets bool value populate from URI query and set it to request context. If query has not values sets given values
+func Populate(defaultPopulated bool) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
+			populate, err := strconv.ParseBool(request.URL.Query().Get("populated"))
+			if err != nil {
+				populate = defaultPopulated
+			}
+
+			ctxTemplate := context.WithValue(request.Context(), populateKey, populate)
+			next.ServeHTTP(writer, request.WithContext(ctxTemplate))
+		})
+	}
+}
+
 // DateRange gets from and to values from URI query and set it to request context. If query has not values sets given values
 func DateRange(defaultFrom, defaultTo string) func(next http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {

api/middleware/middleware.go

@@ -19,6 +19,7 @@ var (
 	databaseKey          ContextKey = "database"
 	searcherKey          ContextKey = "searcher"
 	triggerIDKey         ContextKey = "triggerID"
+	populateKey          ContextKey = "populated"
 	contactIDKey         ContextKey = "contactID"
 	tagKey               ContextKey = "tag"
 	subscriptionIDKey    ContextKey = "subscriptionID"
@@ -48,6 +49,11 @@ func GetTriggerID(request *http.Request) string {
 	return request.Context().Value(triggerIDKey).(string)
 }
 
+// GetPopulated get populate bool from request context, which was sets in TriggerContext middleware
+func GetPopulated(request *http.Request) bool {
+	return request.Context().Value(populateKey).(bool)
+}
+
 // GetTag gets tag string from request context, which was sets in TagContext middleware
 func GetTag(request *http.Request) string {
 	return request.Context().Value(tagKey).(string)

datatypes.go

@@ -3,6 +3,7 @@ package moira
 import (
 	"bytes"
 	"fmt"
+	"html/template"
 	"math"
 	"strconv"
 	"strings"
@@ -103,6 +104,23 @@ func (event *NotificationEvent) CreateMessage(location *time.Location) string {
 // NotificationEvents represents slice of NotificationEvent
 type NotificationEvents []NotificationEvent
 
+type templateData struct {
+	Trigger templateTrigger
+	Events  []templateEvent
+}
+
+type templateEvent struct {
+	Metric         string
+	MetricElements []string
+	Timestamp      int64
+	Value          *float64
+	State          State
+}
+
+type templateTrigger struct {
+	Name string `json:"name"`
+}
+
 // TriggerData represents trigger object
 type TriggerData struct {
 	ID         string   `json:"id"`
@@ -115,6 +133,35 @@ type TriggerData struct {
 	Tags       []string `json:"__notifier_trigger_tags"`
 }
 
+func (trigger TriggerData) GetPopulatedDescription(events NotificationEvents) (string, error) {
+	buffer := new(bytes.Buffer)
+	templateEvents := make([]templateEvent, 0, len(events))
+
+	for _, data := range events {
+		event := templateEvent{
+			Metric:         data.Metric,
+			MetricElements: strings.Split(data.Metric, "."),
+			Timestamp:      data.Timestamp,
+			State:          data.State,
+			Value:          data.Value,
+		}
+
+		templateEvents = append(templateEvents, event)
+	}
+
+	dataToExecute := templateData{
+		Trigger: templateTrigger{Name: trigger.Name},
+		Events:  templateEvents,
+	}
+
+	triggerTemplate := template.Must(template.New("populate-description").Parse(trigger.Desc))
+	if err := triggerTemplate.Execute(buffer, dataToExecute); err != nil {
+		return "", err
+	}
+
+	return buffer.String(), nil
+}
+
 // GetTriggerURI gets frontUri and returns triggerUrl, returns empty string on selfcheck and test notifications
 func (trigger TriggerData) GetTriggerURI(frontURI string) string {
 	if trigger.ID != "" {

datatypes_test.go

@@ -244,6 +244,50 @@ func TestTriggerData_GetTags(t *testing.T) {
 	})
 }
 
+func TestTriggerData_TemplateDescription(t *testing.T) {
+
+	Convey("Test templates", t, func() {
+		var trigger = TriggerData{Name: "TestName"}
+		trigger.Desc = "\n" +
+			"Trigger name: {{.Trigger.Name}}\n" +
+			"{{range $v := .Events }}\n" +
+			"Metric: {{$v.Metric}}\n" +
+			"MetricElements: {{$v.MetricElements}}\n" +
+			"Timestamp: {{$v.Timestamp}}\n" +
+			"Value: {{$v.Value}}\n" +
+			"State: {{$v.State}}\n" +
+			"{{end}}\n" +
+			"https://grafana.yourhost.com/some-dashboard{{ range $i, $v := .Events }}{{ if ne $i 0 }}&{{ else }}?{{ end }}var-host={{ $v.Metric }}{{ end }}\n"
+
+		var data = NotificationEvents{{Metric: "1"}, {Metric: "2"}}
+
+		Convey("Test nil data", func() {
+
+			expected, err := trigger.GetPopulatedDescription(nil)
+			So(err, ShouldBeNil)
+			So(`
+Trigger name: TestName
+
+https://grafana.yourhost.com/some-dashboard
+`, ShouldResemble, expected)
+		})
+
+		Convey("Test data", func() {
+			expected, err := trigger.GetPopulatedDescription(data)
+			So(err, ShouldBeNil)
+			So("\nTrigger name: TestName\n\nMetric: 1\nMetricElements: [1]\nTimestamp: 0\nValue: <nil>\nState: \n\nMetric: 2\nMetricElements: [2]\nTimestamp: 0\nValue: <nil>\nState: \n\nhttps://grafana.yourhost.com/some-dashboard?var-host=1&var-host=2\n", ShouldResemble, expected)
+		})
+
+		Convey("Test description without templates", func() {
+			anotherText := "Another text"
+			trigger.Desc = anotherText
+			expected, err := trigger.GetPopulatedDescription(data)
+			So(err, ShouldBeNil)
+			So(anotherText, ShouldEqual, expected)
+		})
+	})
+}
+
 func TestScheduledNotification_GetKey(t *testing.T) {
 	Convey("Get key", t, func() {
 		notification := ScheduledNotification{

notifier/notifier.go

@@ -160,6 +160,12 @@ func (notifier *StandardNotifier) runSender(sender moira.Sender, ch chan Notific
 				notifier.logger.Errorf(buildErr)
 			}
 		}
+
+		pkg.Trigger.Desc, err = pkg.Trigger.GetPopulatedDescription(pkg.Events)
+		if err != nil {
+			notifier.logger.Errorf("Error populate description: %v", err)
+		}
+
 		err = sender.SendEvents(pkg.Events, pkg.Contact, pkg.Trigger, plot, pkg.Throttled)
 		if err == nil {
 			if metric, found := notifier.metrics.SendersOkMetrics.GetRegisteredMeter(pkg.Contact.Type); found {