introduce context for event

add newrelic instrumentation

Author: ajay.k

Gopkg.lock

@@ -52,3 +52,7 @@
 [[constraint]]
   name = "google.golang.org/grpc"
   version = "1.8.2"
+
+[[constraint]]
+  name = "github.com/newrelic/go-agent"
+  version = "~1.11.0"

Gopkg.toml

@@ -17,12 +17,14 @@ setup:
 	go get github.com/DATA-DOG/godog/cmd/godog
 	go get -u github.com/go-playground/overalls
 	go get -u github.com/golang/dep/cmd/dep
-	dep ensure
+	dep ensure -v
 	mkdir -p out/
 	go build -o $(APP_EXECUTABLE)
-	cp application.yml.sample application.yml
 	@echo "consul-envoy-xds is setup!! Run make test to run tests"
 
+copy-config:
+	cp application.yml.sample application.yml
+
 build-deps:
 	go install
 
@@ -50,7 +52,7 @@ lint:
 		golint $$p | { grep -vwE "exported (var|function|method|type|const) \S+ should have comment" || true; } \
 	done
 
-test: compile
+test: compile copy-config
 	ENVIRONMENT=test go test $(UNIT_TEST_PACKAGES) -p=1
 
 test-coverage: compile

Makefile

@@ -5,3 +5,4 @@ CONSUL_CLIENT_HOST: localhost
 CONSUL_DC: dc1
 CONSUL_TOKEN: ""
 WATCHED_SERVICE: foo-service
+NEW_RELIC_LICENSE_KEY: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

application.yml.sample

@@ -50,6 +50,18 @@ func (cfg *Config) WatchedServices() []string {
 	return strings.Split(cfg.GetValue("WATCHED_SERVICE"), ",")
 }
 
+func (cfg *Config) AppName() string {
+	return cfg.GetOptionalValue("APP_NAME", "consul-envoy-xds")
+}
+
+func (cfg *Config) NewRelicLicenseKey() string {
+	return cfg.GetValue("NEW_RELIC_LICENSE_KEY")
+}
+
+func (cfg *Config) NewRelicEnabled() bool {
+	return cfg.GetFeature("NEW_RELIC_ENABLED")
+}
+
 func (cfg *Config) WhitelistedRoutes(svc string) []string {
 	canonicalName := strings.Replace(svc, "-", "_", -1)
 	whitelist := cfg.GetOptionalValue(strings.ToUpper(canonicalName)+"_WHITELISTED_ROUTES", "/")

config/config.go

@@ -1,18 +1,19 @@
 package eds
 
 import (
+	"context"
 	"fmt"
-	"time"
-
-	"github.com/gojektech/consul-envoy-xds/agent"
-	"github.com/gojektech/consul-envoy-xds/pubsub"
-
 	"log"
+	"time"
 
 	cp "github.com/envoyproxy/go-control-plane/envoy/api/v2"
 	cpcore "github.com/envoyproxy/go-control-plane/envoy/api/v2/core"
 	eds "github.com/envoyproxy/go-control-plane/envoy/api/v2/endpoint"
 	"github.com/envoyproxy/go-control-plane/envoy/api/v2/route"
+	"github.com/gojektech/consul-envoy-xds/agent"
+	"github.com/gojektech/consul-envoy-xds/eventctx"
+	"github.com/gojektech/consul-envoy-xds/instrument"
+	"github.com/gojektech/consul-envoy-xds/pubsub"
 	"github.com/hashicorp/consul/api"
 	"github.com/hashicorp/consul/watch"
 )
@@ -126,8 +127,11 @@ func (s *service) WatchPlan(publish func(*pubsub.Event)) (*watch.Plan, error) {
 		return nil, err
 	}
 	plan.Handler = func(idx uint64, data interface{}) {
+		txn := instrument.NewRelicApp().StartTransaction("watch", nil, nil)
+		defer txn.End()
 		log.Println(fmt.Sprintf("consul watch triggerred: %v", data))
-		publish(&pubsub.Event{CLA: s.CLA(), Clusters: s.Clusters(), Routes: s.Routes()})
+		ctx := eventctx.SetNewRelicTxn(context.Background(), txn)
+		publish(&pubsub.Event{Context: ctx, CLA: s.CLA(), Clusters: s.Clusters(), Routes: s.Routes()})
 	}
 	return plan, nil
 }

eds/endpoint.go

@@ -0,0 +1,49 @@
+package eventctx
+
+import (
+	"context"
+	"github.com/newrelic/go-agent"
+	"net/http"
+)
+
+const newRelicTxnKey = "CTX_NEW_RELIC_TXN_KEY"
+
+type noOpTransaction struct {
+	http.ResponseWriter
+}
+
+func (t noOpTransaction) End() error {
+	return nil
+}
+
+func (t noOpTransaction) Ignore() error {
+	return nil
+}
+
+func (t noOpTransaction) SetName(name string) error {
+	return nil
+}
+
+func (t noOpTransaction) NoticeError(err error) error {
+	return nil
+}
+
+func (t noOpTransaction) AddAttribute(key string, value interface{}) error {
+	return nil
+}
+
+func (t noOpTransaction) StartSegmentNow() newrelic.SegmentStartTime {
+	return newrelic.SegmentStartTime{}
+}
+
+func NewRelicTxn(ctx context.Context) newrelic.Transaction {
+	val := ctx.Value(newRelicTxnKey)
+	if val == nil {
+		return noOpTransaction{}
+	}
+	return val.(newrelic.Transaction)
+}
+
+func SetNewRelicTxn(ctx context.Context, txn newrelic.Transaction) context.Context {
+	return context.WithValue(ctx, newRelicTxnKey, txn)
+}

eventctx/ctx.go

@@ -0,0 +1,25 @@
+package instrument
+
+import (
+	"log"
+
+	"github.com/gojektech/consul-envoy-xds/config"
+	"github.com/newrelic/go-agent"
+)
+
+var newRelicApp newrelic.Application
+
+func init() {
+	cfg := config.Load()
+	newRelicCfg := newrelic.NewConfig(cfg.AppName(), cfg.NewRelicLicenseKey())
+	newRelicCfg.Enabled = cfg.NewRelicEnabled()
+	var err error
+	newRelicApp, err = newrelic.NewApplication(newRelicCfg)
+	if err != nil {
+		log.Fatal("failed to initialize new relic application", err)
+	}
+}
+
+func NewRelicApp() newrelic.Application {
+	return newRelicApp
+}

instrument/newrelic.go

@@ -4,6 +4,7 @@ import (
 	"log"
 	"sync"
 
+	"context"
 	cp "github.com/envoyproxy/go-control-plane/envoy/api/v2"
 	"github.com/satori/go.uuid"
 )
@@ -21,6 +22,7 @@ type Event struct {
 	CLA      []*cp.ClusterLoadAssignment
 	Clusters []*cp.Cluster
 	Routes   []*cp.RouteConfiguration
+	Context  context.Context
 }
 
 type hub struct {

pubsub/hub.go

@@ -3,6 +3,7 @@ package pubsub
 import (
 	"testing"
 
+	"context"
 	cp "github.com/envoyproxy/go-control-plane/envoy/api/v2"
 	"github.com/stretchr/testify/assert"
 )
@@ -12,7 +13,7 @@ func TestShouldAddSubscriptionToListOfSubscribers(t *testing.T) {
 	subscription := hub.Subscribe()
 	cla := []*cp.ClusterLoadAssignment{}
 	cluster := &cp.Cluster{}
-	event := &Event{cla, []*cp.Cluster{cluster}, nil}
+	event := &Event{Context: context.Background(), CLA: cla, Clusters: []*cp.Cluster{cluster}, Routes: nil}
 	hub.Publish(event)
 	a := <-subscription.Events
 	assert.Equal(t, 1, hub.Size())