Add PagerDuty support package (#1)

* Add PagerDuty code

* Adding files

* remove test file

* go fmt

* Address PR comments

* Add new files

* remove api key

* Add comments

* move function around

* Fix tests

* Add pagerduty test for details

* json marshal test detail struct

* Edit comment

* Pointer receiver

* Address PR comments

.gitignore

@@ -5,3 +5,4 @@ vendor/
 .vscode/
 build/
 bin/
+.idea

api/alert.go

@@ -0,0 +1,6 @@
+package api
+
+// Alert interface is used for the various monitoring and alerting tools for Kelp.
+type Alert interface {
+	Trigger(description string, details interface{}) error
+}

cmd/trade.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/lightyeario/kelp/model"
 	"github.com/lightyeario/kelp/plugins"
+	"github.com/lightyeario/kelp/support/monitoring"
 	"github.com/lightyeario/kelp/support/utils"
 	"github.com/lightyeario/kelp/trader"
 	"github.com/spf13/cobra"
@@ -74,6 +75,10 @@ func init() {
 			HTTP: http.DefaultClient,
 		}
 
+		alert, e := monitoring.MakeAlert(botConfig.ALERT_TYPE, botConfig.ALERT_API_KEY)
+		if e != nil {
+			log.Printf("Unable to set up monitoring for alert type '%s' with the given API key\n", botConfig.ALERT_TYPE)
+		}
 		// --- start initialization of objects ----
 		sdex := plugins.MakeSDEX(
 			client,
@@ -105,6 +110,7 @@ func init() {
 			strat,
 			botConfig.TICK_INTERVAL_SECONDS,
 			dataKey,
+			alert,
 		)
 		// --- end initialization of objects ---
 

glide.yaml

@@ -15,3 +15,5 @@ import:
   - clients/horizon
   - support/config
   - support/errors
+- package: github.com/PagerDuty/go-pagerduty
+  version: 635c5ce271490fba94880e62cde4eea3c1c184b9

support/monitoring/factory.go

@@ -0,0 +1,17 @@
+package monitoring
+
+import (
+	"fmt"
+
+	"github.com/lightyeario/kelp/api"
+)
+
+// MakeAlert creates an Alert based on the type of the service (eg Pager Duty) and its corresponding API key.
+func MakeAlert(alertType string, apiKey string) (api.Alert, error) {
+	switch alertType {
+	case "PagerDuty":
+		return makePagerDuty(apiKey)
+	default:
+		return nil, fmt.Errorf("cannot make alert - invalid alert type: %s", alertType)
+	}
+}

support/monitoring/pagerDuty.go

@@ -0,0 +1,39 @@
+package monitoring
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/PagerDuty/go-pagerduty"
+	"github.com/lightyeario/kelp/api"
+)
+
+type pagerDuty struct {
+	serviceKey string
+}
+
+// ensure pagerDuty implements the api.Alert interface
+var _ api.Alert = &pagerDuty{}
+
+func makePagerDuty(serviceKey string) (api.Alert, error) {
+	return &pagerDuty{
+		serviceKey: serviceKey,
+	}, nil
+}
+
+// Trigger creates a PagerDuty trigger. The description is required and cannot be empty. Supplementary
+// details can be optionally provided as key-value pairs as part of the details parameter.
+func (p *pagerDuty) Trigger(description string, details interface{}) error {
+	event := pagerduty.Event{
+		ServiceKey:  p.serviceKey,
+		Type:        "trigger",
+		Description: description,
+		Details:     details,
+	}
+	response, e := pagerduty.CreateEvent(event)
+	if e != nil {
+		return fmt.Errorf("encountered an error while sending a PagerDuty alert: %s", e)
+	}
+	log.Printf("Triggered PagerDuty alert. Incident key for reference: %s\n", response.IncidentKey)
+	return nil
+}

support/monitoring/pagerDuty_test.go

@@ -0,0 +1,69 @@
+package monitoring
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTriggerPagerDuty(t *testing.T) {
+	const kelpServiceKey = "" // Fill in pager duty service key here during testing.
+	testCases := []struct {
+		testName      string
+		serviceKey    string
+		description   string
+		details       interface{}
+		errorExpected bool
+	}{
+		{
+			testName:      "Tests that a Pager Duty alert was triggered successfully",
+			serviceKey:    kelpServiceKey,
+			description:   "Testing monitoring package. Not a real incident!",
+			details:       nil,
+			errorExpected: false,
+		},
+		// Description cannot be empty
+		{
+			testName:      "Tests that a missing description causes an error",
+			serviceKey:    kelpServiceKey,
+			description:   "",
+			details:       nil,
+			errorExpected: true,
+		},
+		// Service key is invalid
+		{
+			testName:      "Tests that an invalid API key causes an error",
+			serviceKey:    "",
+			description:   "Testing monitoring package. Not a real incident!",
+			details:       nil,
+			errorExpected: true,
+		},
+		{
+			testName:    "Tests that details can be passed through",
+			serviceKey:  kelpServiceKey,
+			description: "Testing monitoring package. Not a real incident!",
+			details: struct {
+				LoadAvg     float64 `json:"load_avg"`
+				NumRequests int     `json:"num_requests"`
+			}{
+				LoadAvg:     0.5,
+				NumRequests: 100,
+			},
+			errorExpected: false,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.testName, func(t *testing.T) {
+			pagerDutyAlert, e := MakeAlert("PagerDuty", tc.serviceKey)
+			if !assert.Nil(t, e) {
+				return
+			}
+			e = pagerDutyAlert.Trigger(tc.description, tc.details)
+			if tc.errorExpected {
+				assert.NotNil(t, e)
+			} else {
+				assert.Nil(t, e)
+			}
+		})
+	}
+}

trader/config.go

@@ -20,6 +20,8 @@ type BotConfig struct {
 	ISSUER_B              string `valid:"-"`
 	TICK_INTERVAL_SECONDS int32  `valid:"-"`
 	HORIZON_URL           string `valid:"-"`
+	ALERT_TYPE            string `valid:"-"`
+	ALERT_API_KEY         string `valid:"-"`
 
 	tradingAccount *string
 	sourceAccount  *string // can be nil

trader/trader.go

@@ -27,6 +27,7 @@ type Trader struct {
 	strat               api.Strategy // the instance of this bot is bound to this strategy
 	tickIntervalSeconds int32
 	dataKey             *model.BotKey
+	alert               api.Alert
 
 	// uninitialized
 	maxAssetA      float64
@@ -47,6 +48,7 @@ func MakeBot(
 	strat api.Strategy,
 	tickIntervalSeconds int32,
 	dataKey *model.BotKey,
+	alert api.Alert,
 ) *Trader {
 	return &Trader{
 		api:                 api,
@@ -57,6 +59,7 @@ func MakeBot(
 		strat:               strat,
 		tickIntervalSeconds: tickIntervalSeconds,
 		dataKey:             dataKey,
+		alert:               alert,
 	}
 }