Remove empty lines between labels in email notifications.

Also add test for email formatting.

Change-Id: I309018b021730dee80f9f5bd05eb1a96bf0d237e

manager/notifier.go

@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"net/http"
@@ -30,19 +31,17 @@ import (
 
 const contentTypeJson = "application/json"
 
-const bodyTmpl = `Subject: [ALERT] {{.Labels.alertname}}: {{.Summary}}
+var bodyTmpl = template.Must(template.New("message").Parse(`Subject: [ALERT] {{.Labels.alertname}}: {{.Summary}}
 
 {{.Description}}
 
 Grouping labels:
 {{range $label, $value := .Labels}}
-  {{$label}} = "{{$value}}"
-{{end}}
+  {{$label}} = "{{$value}}"{{end}}
 
 Payload labels:
 {{range $label, $value := .Payload}}
-  {{$label}} = "{{$value}}"
-{{end}}`
+  {{$label}} = "{{$value}}"{{end}}`))
 
 var (
 	notificationBufferSize = flag.Int("notificationBufferSize", 1000, "Size of buffer for pending notifications.")
@@ -157,6 +156,13 @@ func (n *notifier) sendPagerDutyNotification(serviceKey string, event *Event) er
 	return nil
 }
 
+func writeEmailBody(w io.Writer, event *Event) error {
+	if err := bodyTmpl.Execute(w, event); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (n *notifier) sendEmailNotification(email string, event *Event) error {
 	// Connect to the SMTP smarthost.
 	c, err := smtp.Dial(*smtpSmartHost)
@@ -176,14 +182,7 @@ func (n *notifier) sendEmailNotification(email string, event *Event) error {
 	}
 	defer wc.Close()
 
-	t := template.New("message")
-	if _, err := t.Parse(bodyTmpl); err != nil {
-		return err
-	}
-	if err := t.Execute(wc, event); err != nil {
-		return err
-	}
-	return nil
+	return writeEmailBody(wc, event)
 }
 
 func (n *notifier) handleNotification(event *Event, config *pb.NotificationConfig, i IsInhibitedInterrogator) {

manager/notifier_test.go

@@ -0,0 +1,56 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package manager
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestWriteEmailBody(t *testing.T) {
+	event := &Event{
+		Summary:     "Testsummary",
+		Description: "Test alert description, something went wrong here.",
+		Labels: EventLabels{
+			"alertname":       "TestAlert",
+			"grouping_label1": "grouping_value1",
+			"grouping_label2": "grouping_value2",
+		},
+		Payload: EventPayload{
+			"payload_label1": "payload_value1",
+			"payload_label2": "payload_value2",
+		},
+	}
+	buf := &bytes.Buffer{}
+	writeEmailBody(buf, event)
+
+	expected := `Subject: [ALERT] TestAlert: Testsummary
+
+Test alert description, something went wrong here.
+
+Grouping labels:
+
+  alertname = "TestAlert"
+  grouping_label1 = "grouping_value1"
+  grouping_label2 = "grouping_value2"
+
+Payload labels:
+
+  payload_label1 = "payload_value1"
+  payload_label2 = "payload_value2"`
+
+	if buf.String() != expected {
+		t.Fatalf("Expected:\n%s\n\nGot:\n%s", expected, buf.String())
+	}
+}