Add links to pagerduty2 alerts

 * Change PagerDuty2Service.Handler to return (alert.Handler, error)

alert.go

@@ -208,15 +208,30 @@ func newAlertNode(et *ExecutingTask, n *pipeline.AlertNode, d NodeDiagnostic) (a
 	}
 
 	for _, pd := range n.PagerDuty2Handlers {
+		links := make([]pagerduty2.LinkTemplate, len(pd.Links))
+		for i, l := range pd.Links {
+			links[i] = pagerduty2.LinkTemplate{
+				Href: l.Href,
+				Text: l.Text,
+			}
+		}
 		c := pagerduty2.HandlerConfig{
 			RoutingKey: pd.RoutingKey,
+			Links:      links,
+		}
+		h, err := et.tm.PagerDuty2Service.Handler(c, ctx...)
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to create PagerDuty2 handler")
 		}
-		h := et.tm.PagerDuty2Service.Handler(c, ctx...)
 		an.handlers = append(an.handlers, h)
 	}
 	if len(n.PagerDuty2Handlers) == 0 && (et.tm.PagerDuty2Service != nil && et.tm.PagerDuty2Service.Global()) {
 		c := pagerduty2.HandlerConfig{}
-		h := et.tm.PagerDuty2Service.Handler(c, ctx...)
+
+		h, err := et.tm.PagerDuty2Service.Handler(c, ctx...)
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to create PagerDuty2 handler")
+		}
 		an.handlers = append(an.handlers, h)
 	}
 

pipeline/alert.go

@@ -1019,18 +1019,49 @@ type PagerDuty2Handler struct {
 	// The routing key to use for the alert.
 	// Defaults to the value in the configuration if empty.
 	RoutingKey string `json:"routingKey"`
+	// tick:ignore
+	Links []Link `tick:"Link" json:"links"`
 
 	// tick:ignore
 	_ string `tick:"ServiceKey"`
 }
 
+// tick:ignore
+type Link struct {
+	Href string `json:"href"`
+	Text string `json:"text"`
+}
+
 // Allow ServiceKey as backwards compatible way to set the routing key
 // tick:property
 func (pd2 *PagerDuty2Handler) ServiceKey(serviceKey string) *PagerDuty2Handler {
 	pd2.RoutingKey = serviceKey
 	return pd2
 }
 
+// Set a link to be reported to pagerduty
+//
+// Example:
+//    stream
+//      |alert()
+//        .pagerduty2()
+//          .link('https://grafana.example.com/dashboard/db/thechart', 'Overview Graph')
+//          .link('https://grafana.example.com/dashboard/db/service_{{ .index Tags "service" }}', 'Service Graph')
+//          .link('https://grafana.example.com/')
+// tick:property
+func (pd2 *PagerDuty2Handler) Link(url string, text ...string) *PagerDuty2Handler {
+	linkText := ""
+	if len(text) > 0 {
+		linkText = text[0]
+	}
+	link := Link{
+		Href: url,
+		Text: linkText,
+	}
+	pd2.Links = append(pd2.Links, link)
+	return pd2
+}
+
 // Send the alert to HipChat.
 // For step-by-step instructions on setting up Kapacitor with HipChat, see the [Event Handler Setup Guide](https://docs.influxdata.com//kapacitor/latest/guides/event-handler-setup/#hipchat-setup).
 // To allow Kapacitor to post to HipChat,

pipeline/tick/alert.go

@@ -121,6 +121,13 @@ func (n *AlertNode) Build(a *pipeline.AlertNode) (ast.Node, error) {
 	for _, h := range a.PagerDuty2Handlers {
 		n.Dot("pagerDuty2").
 			Dot("routingKey", h.RoutingKey)
+		for _, l := range h.Links {
+			if len(l.Text) > 0 {
+				n.Dot("link", l.Href, l.Text)
+			} else {
+				n.Dot("link", l.Href)
+			}
+		}
 	}
 
 	for _, h := range a.PushoverHandlers {

pipeline/tick/alert_test.go

@@ -314,6 +314,7 @@ func TestAlertPagerDuty2(t *testing.T) {
 	pipe, _, from := StreamFrom()
 	handler := from.Alert().PagerDuty2()
 	handler.RoutingKey = "LeafsNation"
+	handler.Link("https://example.com/chart", "some chart")
 
 	want := `stream
     |from()
@@ -324,6 +325,49 @@ func TestAlertPagerDuty2(t *testing.T) {
         .history(21)
         .pagerDuty2()
         .routingKey('LeafsNation')
+        .link('https://example.com/chart', 'some chart')
+`
+	PipelineTickTestHelper(t, pipe, want)
+}
+
+func TestAlertPagerDuty2MissingLinkText(t *testing.T) {
+	pipe, _, from := StreamFrom()
+	handler := from.Alert().PagerDuty2()
+	handler.RoutingKey = "LeafsNation"
+	handler.Link("https://example.com/chart")
+
+	want := `stream
+    |from()
+    |alert()
+        .id('{{ .Name }}:{{ .Group }}')
+        .message('{{ .ID }} is {{ .Level }}')
+        .details('{{ json . }}')
+        .history(21)
+        .pagerDuty2()
+        .routingKey('LeafsNation')
+        .link('https://example.com/chart')
+`
+	PipelineTickTestHelper(t, pipe, want)
+}
+
+func TestAlertPagerDuty2MultipleLinks(t *testing.T) {
+	pipe, _, from := StreamFrom()
+	handler := from.Alert().PagerDuty2()
+	handler.RoutingKey = "LeafsNation"
+	handler.Link("https://example.com/chart", "some chart")
+	handler.Link("https://example.com/details", "details")
+
+	want := `stream
+    |from()
+    |alert()
+        .id('{{ .Name }}:{{ .Group }}')
+        .message('{{ .ID }} is {{ .Level }}')
+        .details('{{ json . }}')
+        .history(21)
+        .pagerDuty2()
+        .routingKey('LeafsNation')
+        .link('https://example.com/chart', 'some chart')
+        .link('https://example.com/details', 'details')
 `
 	PipelineTickTestHelper(t, pipe, want)
 }

server/server_test.go

@@ -8795,6 +8795,16 @@ func TestServer_ListServiceTests(t *testing.T) {
 						"Category":    "",
 					},
 					"timestamp": "2014-11-12T11:45:26.371Z",
+					"links": []interface{}{
+						map[string]interface{}{
+							"href": "https://example.com/a",
+							"text": "a",
+						},
+						map[string]interface{}{
+							"href": "https://example.com/b",
+							"text": "b",
+						},
+					},
 				},
 			},
 			{

services/alert/service.go

@@ -102,7 +102,7 @@ type Service struct {
 		Handler(pagerduty.HandlerConfig, ...keyvalue.T) alert.Handler
 	}
 	PagerDuty2Service interface {
-		Handler(pagerduty2.HandlerConfig, ...keyvalue.T) alert.Handler
+		Handler(pagerduty2.HandlerConfig, ...keyvalue.T) (alert.Handler, error)
 	}
 	PushoverService interface {
 		Handler(pushover.HandlerConfig, ...keyvalue.T) alert.Handler
@@ -852,7 +852,10 @@ func (s *Service) createHandlerFromSpec(spec HandlerSpec) (handler, error) {
 		if err != nil {
 			return handler{}, err
 		}
-		h = s.PagerDuty2Service.Handler(c, ctx...)
+		h, err = s.PagerDuty2Service.Handler(c, ctx...)
+		if err != nil {
+			return handler{}, err
+		}
 		h = newExternalHandler(h)
 	case "pushover":
 		c := pushover.HandlerConfig{}

services/pagerduty2/service.go

@@ -9,6 +9,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"sync/atomic"
+	text "text/template"
 	"time"
 
 	"github.com/influxdata/kapacitor/alert"
@@ -160,6 +161,7 @@ type testOptions struct {
 	Level       alert.Level     `json:"level"`
 	Data        alert.EventData `json:"event_data"`
 	Timestamp   time.Time       `json:"timestamp"`
+	Links       []LinkTemplate  `json:"links"`
 }
 
 // TestOptions returns optional values for the test harness
@@ -179,6 +181,14 @@ func (s *Service) TestOptions() interface{} {
 			Fields: make(map[string]interface{}),
 			Result: models.Result{},
 		},
+		Links: []LinkTemplate{{
+			Href: "https://example.com/a",
+			Text: "a",
+		}, {
+			Href: "https://example.com/b",
+			Text: "b",
+		},
+		},
 	}
 }
 
@@ -191,6 +201,7 @@ func (s *Service) Test(options interface{}) error {
 	c := s.config()
 	return s.Alert(
 		c.RoutingKey,
+		o.Links,
 		o.AlertID,
 		o.Description,
 		o.Level,
@@ -203,8 +214,8 @@ func (s *Service) Test(options interface{}) error {
 //
 // The req headers are now required with the API v2:
 // https://v2.developer.pagerduty.com/docs/migrating-to-api-v2
-func (s *Service) Alert(routingKey, alertID, desc string, level alert.Level, timestamp time.Time, data alert.EventData) error {
-	url, post, err := s.preparePost(routingKey, alertID, desc, level, timestamp, data)
+func (s *Service) Alert(routingKey string, links []LinkTemplate, alertID, desc string, level alert.Level, timestamp time.Time, data alert.EventData) error {
+	url, post, err := s.preparePost(routingKey, links, alertID, desc, level, timestamp, data)
 	if err != nil {
 		return err
 	}
@@ -272,7 +283,7 @@ func (s *Service) sendResolve(c Config, routingKey, alertID string) (string, io.
 }
 
 // preparePost is a helper method that sets up the payload for transmission to PagerDuty
-func (s *Service) preparePost(routingKey, alertID, desc string, level alert.Level, timestamp time.Time, data alert.EventData) (string, io.Reader, error) {
+func (s *Service) preparePost(routingKey string, links []LinkTemplate, alertID, desc string, level alert.Level, timestamp time.Time, data alert.EventData) (string, io.Reader, error) {
 	c := s.config()
 	if !c.Enabled {
 		return "", nil, errors.New("service is not enabled")
@@ -318,6 +329,13 @@ func (s *Service) preparePost(routingKey, alertID, desc string, level alert.Leve
 	ap.Payload.Summary = desc
 	ap.Payload.Timestamp = timestamp.Format("2006-01-02T15:04:05.000000000Z07:00")
 
+	if len(links) > 0 {
+		ap.Links = make([]Link, len(links))
+		for i, l := range links {
+			ap.Links[i] = Link{Href: l.Href, Text: l.Text}
+		}
+	}
+
 	if _, ok := data.Tags["host"]; ok {
 		ap.Payload.Source = data.Tags["host"]
 	}
@@ -333,11 +351,19 @@ func (s *Service) preparePost(routingKey, alertID, desc string, level alert.Leve
 	return c.URL, &post, nil
 }
 
+type LinkTemplate struct {
+	Href     string `mapstructure:"href" json:"href"`
+	Text     string `mapstructure:"text" json:"text"`
+	hrefTmpl *text.Template
+	textTmpl *text.Template
+}
+
 // HandlerConfig defines the high-level struct required to connect to PagerDuty
 type HandlerConfig struct {
 	// The routing key to use for the alert.
 	// Defaults to the value in the configuration if empty.
-	RoutingKey string `mapstructure:"routing-key"`
+	RoutingKey string         `mapstructure:"routing-key"`
+	Links      []LinkTemplate `mapstructure:"links"`
 }
 
 type handler struct {
@@ -347,18 +373,60 @@ type handler struct {
 }
 
 // Handler is a bound method to the Service struct that returns the appropriate alert handler for PagerDuty
-func (s *Service) Handler(c HandlerConfig, ctx ...keyvalue.T) alert.Handler {
+func (s *Service) Handler(c HandlerConfig, ctx ...keyvalue.T) (alert.Handler, error) {
+	// Compile link templates
+	for i, l := range c.Links {
+		hrefTmpl, err := text.New("href").Parse(l.Href)
+		if err != nil {
+			return nil, err
+		}
+		c.Links[i].hrefTmpl = hrefTmpl
+		if l.Text != "" {
+			textTmpl, err := text.New("text").Parse(l.Text)
+			if err != nil {
+				return nil, err
+			}
+			c.Links[i].textTmpl = textTmpl
+		}
+	}
 	return &handler{
 		s:    s,
 		c:    c,
 		diag: s.diag.WithContext(ctx...),
-	}
+	}, nil
 }
 
 // Handle is a bound method to the handler that processes a given alert
 func (h *handler) Handle(event alert.Event) {
+	// Execute templates
+	td := event.TemplateData()
+	var hrefBuf bytes.Buffer
+	var textBuf bytes.Buffer
+	for i, l := range h.c.Links {
+		err := l.hrefTmpl.Execute(&hrefBuf, td)
+		if err != nil {
+			h.diag.Error("failed to handle event", err)
+			return
+		}
+		h.c.Links[i].Href = hrefBuf.String()
+		hrefBuf.Reset()
+
+		if l.textTmpl != nil {
+			err = l.textTmpl.Execute(&textBuf, td)
+			if err != nil {
+				h.diag.Error("failed to handle event", err)
+				return
+			}
+			h.c.Links[i].Text = textBuf.String()
+			textBuf.Reset()
+		} else {
+			h.c.Links[i].Text = h.c.Links[i].Href
+		}
+	}
+
 	if err := h.s.Alert(
 		h.c.RoutingKey,
+		h.c.Links,
 		event.State.ID,
 		event.State.Message,
 		event.State.Level,

task_master.go

@@ -140,7 +140,7 @@ type TaskMaster struct {
 	}
 	PagerDuty2Service interface {
 		Global() bool
-		Handler(pagerduty2.HandlerConfig, ...keyvalue.T) alert.Handler
+		Handler(pagerduty2.HandlerConfig, ...keyvalue.T) (alert.Handler, error)
 	}
 	PushoverService interface {
 		Handler(pushover.HandlerConfig, ...keyvalue.T) alert.Handler