Support of custom URL path for alert (#560)

app/vmalert: Support custom URL for alerts source

Add flag `external.alert.source` for configuring custom URL
for alert's source. This may be handy to re-point default source
URL to other systems like Grafana.
Updates #517

app/vmalert/main.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -60,6 +61,8 @@ absolute path to all .yaml files in root.`)
 	evaluationInterval  = flag.Duration("evaluationInterval", time.Minute, "How often to evaluate the rules")
 	notifierURL         = flag.String("notifier.url", "", "Prometheus alertmanager URL. Required parameter. e.g. http://127.0.0.1:9093")
 	externalURL         = flag.String("external.url", "", "External URL is used as alert's source for sent alerts to the notifier")
+	externalAlertSource = flag.String("external.alert.source", "", `External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service.
+eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used`)
 )
 
 func main() {
@@ -76,13 +79,15 @@ func main() {
 		logger.Fatalf("can not get external url: %s ", err)
 	}
 	notifier.InitTemplateFunc(eu)
+	aug, err := getAlertURLGenerator(eu, *externalAlertSource, *validateTemplates)
+	if err != nil {
+		logger.Fatalf("URL generator error: %s", err)
+	}
 
 	manager := &manager{
 		groups:   make(map[uint64]*Group),
 		storage:  datasource.NewVMStorage(*datasourceURL, *basicAuthUsername, *basicAuthPassword, &http.Client{}),
-		notifier: notifier.NewAlertManager(*notifierURL, func(group, alert string) string {
+		notifier: notifier.NewAlertManager(*notifierURL, aug, &http.Client{}),
-			return fmt.Sprintf("%s/api/v1/%s/%s/status", eu, group, alert)
-		}, &http.Client{}),
 	}
 	if *remoteWriteURL != "" {
 		c, err := remotewrite.NewClient(ctx, remotewrite.Config{
@@ -166,6 +171,31 @@ func getExternalURL(externalURL, httpListenAddr string, isSecure bool) (*url.URL
 	return url.Parse(fmt.Sprintf("%s%s%s", schema, hname, port))
 }
 
+func getAlertURLGenerator(externalURL *url.URL, externalAlertSource string, validateTemplate bool) (notifier.AlertURLGenerator, error) {
+	if externalAlertSource == "" {
+		return func(alert notifier.Alert) string {
+			return fmt.Sprintf("%s/api/v1/%s/%s/status", externalURL, strconv.FormatUint(alert.GroupID, 10), strconv.FormatUint(alert.ID, 10))
+		}, nil
+	}
+	if validateTemplate {
+		if err := notifier.ValidateTemplates(map[string]string{
+			"tpl": externalAlertSource,
+		}); err != nil {
+			return nil, fmt.Errorf("error validating source template %s:%w", externalAlertSource, err)
+		}
+	}
+	m := map[string]string{
+		"tpl": externalAlertSource,
+	}
+	return func(alert notifier.Alert) string {
+		templated, err := alert.ExecTemplate(m)
+		if err != nil {
+			logger.Errorf("can not exec source template %s", err)
+		}
+		return fmt.Sprintf("%s/%s", externalURL, templated["tpl"])
+	}, nil
+}
+
 func checkFlags() {
 	if *notifierURL == "" {
 		flag.PrintDefaults()

app/vmalert/main_test.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"testing"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/notifier"
+)
+
+func TestGetExternalURL(t *testing.T) {
+	expURL := "https://vicotriametrics.com/path"
+	u, err := getExternalURL(expURL, "", false)
+	if err != nil {
+		t.Errorf("unexpected error %s", err)
+	}
+	if u.String() != expURL {
+		t.Errorf("unexpected url want %s, got %s", expURL, u.String())
+	}
+	h, _ := os.Hostname()
+	expURL = fmt.Sprintf("https://%s:4242", h)
+	u, err = getExternalURL("", "0.0.0.0:4242", true)
+	if err != nil {
+		t.Errorf("unexpected error %s", err)
+	}
+	if u.String() != expURL {
+		t.Errorf("unexpected url want %s, got %s", expURL, u.String())
+	}
+}
+
+func TestGetAlertURLGenerator(t *testing.T) {
+	testAlert := notifier.Alert{GroupID: 42, ID: 2, Value: 4}
+	u, _ := url.Parse("https://victoriametrics.com/path")
+	fn, err := getAlertURLGenerator(u, "", false)
+	if err != nil {
+		t.Errorf("unexpected error %s", err)
+	}
+	if exp := "https://victoriametrics.com/path/api/v1/42/2/status"; exp != fn(testAlert) {
+		t.Errorf("unexpected url want %s, got %s", exp, fn(testAlert))
+	}
+	_, err = getAlertURLGenerator(nil, "foo?{{invalid}}", true)
+	if err == nil {
+		t.Errorf("exptected tempalte validation error got nil")
+	}
+	fn, err = getAlertURLGenerator(u, "foo?query={{$value}}", true)
+	if err != nil {
+		t.Errorf("unexpected error %s", err)
+	}
+	if exp := "https://victoriametrics.com/path/foo?query=4"; exp != fn(testAlert) {
+		t.Errorf("unexpected url want %s, got %s", exp, fn(testAlert))
+	}
+}

app/vmalert/notifier/alert_test.go

@@ -1,13 +1,10 @@
 package notifier
 
 import (
-	"net/url"
 	"testing"
 )
 
 func TestAlert_ExecTemplate(t *testing.T) {
-	u, _ := url.Parse("https://victoriametrics.com/path")
-	InitTemplateFunc(u)
 	testCases := []struct {
 		name        string
 		alert       *Alert

app/vmalert/notifier/alertmanager.go

@@ -46,7 +46,7 @@ func (am *AlertManager) Send(ctx context.Context, alerts []Alert) error {
 }
 
 // AlertURLGenerator returns URL to single alert by given name
-type AlertURLGenerator func(group, alert string) string
+type AlertURLGenerator func(Alert) string
 
 const alertManagerPath = "/api/v2/alerts"
 

app/vmalert/notifier/alertmanager_request.qtpl

@@ -1,15 +1,14 @@
 {% import (
-    "strconv"
     "time"
 ) %}
 {% stripspace %}
 
-{% func amRequest(alerts []Alert, generatorURL func(string, string) string) %}
+{% func amRequest(alerts []Alert, generatorURL func(Alert) string) %}
 [
 {% for i, alert := range alerts %}
 {
     "startsAt":{%q= alert.Start.Format(time.RFC3339Nano) %},
-	"generatorURL": {%q= generatorURL(strconv.FormatUint(alert.GroupID, 10), strconv.FormatUint(alert.ID, 10)) %},
+    "generatorURL": {%q= generatorURL(alert) %},
     {% if !alert.End.IsZero() %}
     "endsAt":{%q= alert.End.Format(time.RFC3339Nano) %},
     {% endif %}

app/vmalert/notifier/alertmanager_request.qtpl.go

@@ -1,131 +1,130 @@
 // Code generated by qtc from "alertmanager_request.qtpl". DO NOT EDIT.
 // See https://github.com/valyala/quicktemplate for details.
 
-//line notifier/alertmanager_request.qtpl:1
+//line app/vmalert/notifier/alertmanager_request.qtpl:1
 package notifier
 
-//line notifier/alertmanager_request.qtpl:1
+//line app/vmalert/notifier/alertmanager_request.qtpl:1
 import (
-	"strconv"
 	"time"
 )
 
-//line notifier/alertmanager_request.qtpl:7
+//line app/vmalert/notifier/alertmanager_request.qtpl:6
 import (
 	qtio422016 "io"
 
 	qt422016 "github.com/valyala/quicktemplate"
 )
 
-//line notifier/alertmanager_request.qtpl:7
+//line app/vmalert/notifier/alertmanager_request.qtpl:6
 var (
 	_ = qtio422016.Copy
 	_ = qt422016.AcquireByteBuffer
 )
 
-//line notifier/alertmanager_request.qtpl:7
+//line app/vmalert/notifier/alertmanager_request.qtpl:6
-func streamamRequest(qw422016 *qt422016.Writer, alerts []Alert, generatorURL func(string, string) string) {
+func streamamRequest(qw422016 *qt422016.Writer, alerts []Alert, generatorURL func(Alert) string) {
-//line notifier/alertmanager_request.qtpl:7
+//line app/vmalert/notifier/alertmanager_request.qtpl:6
 	qw422016.N().S(`[`)
-//line notifier/alertmanager_request.qtpl:9
+//line app/vmalert/notifier/alertmanager_request.qtpl:8
 	for i, alert := range alerts {
-//line notifier/alertmanager_request.qtpl:9
+//line app/vmalert/notifier/alertmanager_request.qtpl:8
 		qw422016.N().S(`{"startsAt":`)
-//line notifier/alertmanager_request.qtpl:11
+//line app/vmalert/notifier/alertmanager_request.qtpl:10
 		qw422016.N().Q(alert.Start.Format(time.RFC3339Nano))
-//line notifier/alertmanager_request.qtpl:11
+//line app/vmalert/notifier/alertmanager_request.qtpl:10
 		qw422016.N().S(`,"generatorURL":`)
-//line notifier/alertmanager_request.qtpl:12
+//line app/vmalert/notifier/alertmanager_request.qtpl:11
-		qw422016.N().Q(generatorURL(strconv.FormatUint(alert.GroupID, 10), strconv.FormatUint(alert.ID, 10)))
+		qw422016.N().Q(generatorURL(alert))
-//line notifier/alertmanager_request.qtpl:12
+//line app/vmalert/notifier/alertmanager_request.qtpl:11
 		qw422016.N().S(`,`)
-//line notifier/alertmanager_request.qtpl:13
+//line app/vmalert/notifier/alertmanager_request.qtpl:12
 		if !alert.End.IsZero() {
-//line notifier/alertmanager_request.qtpl:13
+//line app/vmalert/notifier/alertmanager_request.qtpl:12
 			qw422016.N().S(`"endsAt":`)
-//line notifier/alertmanager_request.qtpl:14
+//line app/vmalert/notifier/alertmanager_request.qtpl:13
 			qw422016.N().Q(alert.End.Format(time.RFC3339Nano))
-//line notifier/alertmanager_request.qtpl:14
+//line app/vmalert/notifier/alertmanager_request.qtpl:13
 			qw422016.N().S(`,`)
-//line notifier/alertmanager_request.qtpl:15
+//line app/vmalert/notifier/alertmanager_request.qtpl:14
 		}
-//line notifier/alertmanager_request.qtpl:15
+//line app/vmalert/notifier/alertmanager_request.qtpl:14
 		qw422016.N().S(`"labels": {"alertname":`)
-//line notifier/alertmanager_request.qtpl:17
+//line app/vmalert/notifier/alertmanager_request.qtpl:16
 		qw422016.N().Q(alert.Name)
-//line notifier/alertmanager_request.qtpl:18
+//line app/vmalert/notifier/alertmanager_request.qtpl:17
 		for k, v := range alert.Labels {
-//line notifier/alertmanager_request.qtpl:18
+//line app/vmalert/notifier/alertmanager_request.qtpl:17
 			qw422016.N().S(`,`)
-//line notifier/alertmanager_request.qtpl:19
+//line app/vmalert/notifier/alertmanager_request.qtpl:18
 			qw422016.N().Q(k)
-//line notifier/alertmanager_request.qtpl:19
+//line app/vmalert/notifier/alertmanager_request.qtpl:18
 			qw422016.N().S(`:`)
-//line notifier/alertmanager_request.qtpl:19
+//line app/vmalert/notifier/alertmanager_request.qtpl:18
 			qw422016.N().Q(v)
-//line notifier/alertmanager_request.qtpl:20
+//line app/vmalert/notifier/alertmanager_request.qtpl:19
 		}
-//line notifier/alertmanager_request.qtpl:20
+//line app/vmalert/notifier/alertmanager_request.qtpl:19
 		qw422016.N().S(`},"annotations": {`)
-//line notifier/alertmanager_request.qtpl:23
+//line app/vmalert/notifier/alertmanager_request.qtpl:22
 		c := len(alert.Annotations)
 
-//line notifier/alertmanager_request.qtpl:24
+//line app/vmalert/notifier/alertmanager_request.qtpl:23
 		for k, v := range alert.Annotations {
-//line notifier/alertmanager_request.qtpl:25
+//line app/vmalert/notifier/alertmanager_request.qtpl:24
 			c = c - 1
 
-//line notifier/alertmanager_request.qtpl:26
+//line app/vmalert/notifier/alertmanager_request.qtpl:25
 			qw422016.N().Q(k)
-//line notifier/alertmanager_request.qtpl:26
+//line app/vmalert/notifier/alertmanager_request.qtpl:25
 			qw422016.N().S(`:`)
-//line notifier/alertmanager_request.qtpl:26
+//line app/vmalert/notifier/alertmanager_request.qtpl:25
 			qw422016.N().Q(v)
-//line notifier/alertmanager_request.qtpl:26
+//line app/vmalert/notifier/alertmanager_request.qtpl:25
 			if c > 0 {
-//line notifier/alertmanager_request.qtpl:26
+//line app/vmalert/notifier/alertmanager_request.qtpl:25
 				qw422016.N().S(`,`)
-//line notifier/alertmanager_request.qtpl:26
+//line app/vmalert/notifier/alertmanager_request.qtpl:25
 			}
-//line notifier/alertmanager_request.qtpl:27
+//line app/vmalert/notifier/alertmanager_request.qtpl:26
 		}
-//line notifier/alertmanager_request.qtpl:27
+//line app/vmalert/notifier/alertmanager_request.qtpl:26
 		qw422016.N().S(`}}`)
-//line notifier/alertmanager_request.qtpl:30
+//line app/vmalert/notifier/alertmanager_request.qtpl:29
 		if i != len(alerts)-1 {
-//line notifier/alertmanager_request.qtpl:30
+//line app/vmalert/notifier/alertmanager_request.qtpl:29
 			qw422016.N().S(`,`)
-//line notifier/alertmanager_request.qtpl:30
+//line app/vmalert/notifier/alertmanager_request.qtpl:29
 		}
-//line notifier/alertmanager_request.qtpl:31
+//line app/vmalert/notifier/alertmanager_request.qtpl:30
 	}
-//line notifier/alertmanager_request.qtpl:31
+//line app/vmalert/notifier/alertmanager_request.qtpl:30
 	qw422016.N().S(`]`)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 }
 
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
-func writeamRequest(qq422016 qtio422016.Writer, alerts []Alert, generatorURL func(string, string) string) {
+func writeamRequest(qq422016 qtio422016.Writer, alerts []Alert, generatorURL func(Alert) string) {
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	qw422016 := qt422016.AcquireWriter(qq422016)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	streamamRequest(qw422016, alerts, generatorURL)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	qt422016.ReleaseWriter(qw422016)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 }
 
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
-func amRequest(alerts []Alert, generatorURL func(string, string) string) string {
+func amRequest(alerts []Alert, generatorURL func(Alert) string) string {
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	qb422016 := qt422016.AcquireByteBuffer()
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	writeamRequest(qb422016, alerts, generatorURL)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	qs422016 := string(qb422016.B)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	qt422016.ReleaseByteBuffer(qb422016)
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 	return qs422016
-//line notifier/alertmanager_request.qtpl:33
+//line app/vmalert/notifier/alertmanager_request.qtpl:32
 }

app/vmalert/notifier/alertmanager_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"testing"
 	"time"
 )
@@ -57,8 +58,8 @@ func TestAlertManager_Send(t *testing.T) {
 	})
 	srv := httptest.NewServer(mux)
 	defer srv.Close()
-	am := NewAlertManager(srv.URL, func(group, name string) string {
+	am := NewAlertManager(srv.URL, func(alert Alert) string {
-		return group + "/" + name
+		return strconv.FormatUint(alert.GroupID, 10) + "/" + strconv.FormatUint(alert.ID, 10)
 	}, srv.Client())
 	if err := am.Send(context.Background(), []Alert{{}, {}}); err == nil {
 		t.Error("expected connection error got nil")

app/vmalert/notifier/package_test.go

@@ -0,0 +1,13 @@
+package notifier
+
+import (
+	"net/url"
+	"os"
+	"testing"
+)
+
+func TestMain(m *testing.M) {
+	u, _ := url.Parse("https://victoriametrics.com/path")
+	InitTemplateFunc(u)
+	os.Exit(m.Run())
+}