api/v2: fix alerts with multiple receivers (#1948)

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

api/v2/api.go

@@ -432,8 +432,8 @@ func alertToOpenAPIAlert(alert *types.Alert, status types.AlertStatus, receivers
 	endsAt := strfmt.DateTime(alert.EndsAt)
 
 	apiReceivers := make([]*open_api_models.Receiver, 0, len(receivers))
-	for _, name := range receivers {
-		apiReceivers = append(apiReceivers, &open_api_models.Receiver{Name: &name})
+	for i := range receivers {
+		apiReceivers = append(apiReceivers, &open_api_models.Receiver{Name: &receivers[i]})
 	}
 
 	fp := alert.Fingerprint().String()

api/v2/api_test.go

@@ -19,10 +19,13 @@ import (
 	"time"
 
 	"github.com/go-openapi/strfmt"
+	"github.com/prometheus/common/model"
+	"github.com/stretchr/testify/require"
 
 	open_api_models "github.com/prometheus/alertmanager/api/v2/models"
 	general_ops "github.com/prometheus/alertmanager/api/v2/restapi/operations/general"
 	"github.com/prometheus/alertmanager/config"
+	"github.com/prometheus/alertmanager/types"
 )
 
 // If api.peers == nil, Alertmanager cluster feature is disabled. Make sure to
@@ -122,3 +125,46 @@ func TestGetSilencesHandler(t *testing.T) {
 		assertEqualStrings(t, "silence-"+strconv.Itoa(i)+"-"+*sil.Status.State, *sil.ID)
 	}
 }
+
+func convertDateTime(ts time.Time) *strfmt.DateTime {
+	dt := strfmt.DateTime(ts)
+	return &dt
+}
+
+func TestAlertToOpenAPIAlert(t *testing.T) {
+	var (
+		start     = time.Now().Add(-time.Minute)
+		updated   = time.Now()
+		active    = "active"
+		fp        = "0223b772b51c29e1"
+		receivers = []string{"receiver1", "receiver2"}
+
+		alert = &types.Alert{
+			Alert: model.Alert{
+				Labels:   model.LabelSet{"severity": "critical", "alertname": "alert1"},
+				StartsAt: start,
+			},
+			UpdatedAt: updated,
+		}
+	)
+	openAPIAlert := alertToOpenAPIAlert(alert, types.AlertStatus{State: types.AlertStateActive}, receivers)
+	require.Equal(t, &open_api_models.GettableAlert{
+		Annotations: open_api_models.LabelSet{},
+		Alert: open_api_models.Alert{
+			Labels: open_api_models.LabelSet{"severity": "critical", "alertname": "alert1"},
+		},
+		Status: &open_api_models.AlertStatus{
+			State:       &active,
+			InhibitedBy: []string{},
+			SilencedBy:  []string{},
+		},
+		StartsAt:    convertDateTime(start),
+		EndsAt:      convertDateTime(time.Time{}),
+		UpdatedAt:   convertDateTime(updated),
+		Fingerprint: &fp,
+		Receivers: []*open_api_models.Receiver{
+			&open_api_models.Receiver{Name: &receivers[0]},
+			&open_api_models.Receiver{Name: &receivers[1]},
+		},
+	}, openAPIAlert)
+}