add interfaces to enable out-of-the-box instrumentations

Ivan Rylach · ivanRylach · commit 16269a2b1ff8 · 2021-09-30T14:54:39.000-05:00
diff --git a/README.md b/README.md
@@ -27,7 +27,7 @@ Plugin - [`idempotent-requests`](https://github.com/checkr/kong-plugin-idempoten
 | --- | --- | --- | --- |
 | `MONGODB_URI` | yes | `mongodb://root:password123@localhost:27017` | URI to connect to MongoDB |
 | `OPENTRACING_ENABLED` | no | `true` | Enable `opentracing` |
-| `OPENTRACING_TRACER_IMPLEMENTATION` | no | `datadog` | Use Datadog tracer implementation |
+| `OPENTRACING_TRACER_IMPLEMENTATION` | no | `datadog` | [Use Datadog tracer implementation](https://docs.datadoghq.com/tracing/setup_overview/setup/go/?tab=containers) |
 
 ## Example topology
 
diff --git a/go.sum b/go.sum
@@ -70,7 +70,6 @@ github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfU
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/golang/protobuf v1.3.3 h1:gyjaxf+svBWX08ZjK86iN9geUJF0H6gp2IRKX6Nf6/I=
 github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
 github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
@@ -89,6 +88,7 @@ github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.2 h1:X2ev0eStA3AbceY54o37/0PQ/UWqKEiiO2dKL5OPaFM=
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
 github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/pprof v0.0.0-20210423192551-a2663126120b/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
@@ -147,6 +147,7 @@ github.com/sirupsen/logrus v1.7.0/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic
 github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1 h1:2vfRuCMp5sSVIDSqO8oNnWJq7mPa6KVP3iPIwFBuy8A=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
diff --git a/main.go b/main.go
@@ -19,16 +19,17 @@ func main() {
 	zap.ReplaceGlobals(logger)
 	defer logger.Sync()
 
+	var tracer tracing.Tracer
 	if tracing.GetConfig().TracingEnabled {
-		tracers := tracing.NewTracer()
-		opentracing.SetGlobalTracer(tracers.OpentracingTracer())
-		defer tracers.Stop()
+		tracer = tracing.NewTracer()
+		opentracing.SetGlobalTracer(tracer.OpentracingTracer())
+		defer tracer.Stop()
 	}
 
-	mongo := mongodb.NewClient()
+	mongo := mongodb.NewClient(tracer)
 	capturesRepo := captures_mongo.NewRepository(mongo)
 
-	httpServer := http.NewServer(capturesRepo)
+	httpServer := http.NewServer(tracer, capturesRepo)
 	go httpServer.Start()
 
 	waitForShutdownSignal()
diff --git a/pkg/http/captures_allocate_test.go b/pkg/http/captures_allocate_test.go
@@ -3,6 +3,7 @@ package http
 import (
 	"bytes"
 	"checkr.com/idempotent-requests/pkg/captures/captures_mock"
+	"checkr.com/idempotent-requests/pkg/tracing"
 	"encoding/base64"
 	"encoding/json"
 	"github.com/stretchr/testify/assert"
@@ -16,7 +17,9 @@ const CapturesV2URL = "/api/v2/captures"
 
 func TestCaptures_Allocate(t *testing.T) {
 	capturesRepo := captures_mock.NewRepositoryImpl()
-	router := NewRouter(capturesRepo)
+	tracer := tracing.MockTracer{}
+
+	router := NewRouter(tracer, capturesRepo)
 
 	tests := []struct {
 		name       string
diff --git a/pkg/http/captures_record_test.go b/pkg/http/captures_record_test.go
@@ -2,6 +2,7 @@ package http
 
 import (
 	"checkr.com/idempotent-requests/pkg/captures/captures_mock"
+	"checkr.com/idempotent-requests/pkg/tracing"
 	"checkr.com/idempotent-requests/pkg/views"
 	"encoding/base64"
 	"github.com/gin-gonic/gin"
@@ -21,7 +22,9 @@ const (
 
 func TestCaptures_Record(t *testing.T) {
 	capturesRepo := captures_mock.NewRepositoryImpl()
-	router := NewRouter(capturesRepo)
+	tracer := tracing.MockTracer{}
+
+	router := NewRouter(tracer, capturesRepo)
 
 	tests := []struct {
 		name               string
diff --git a/pkg/http/handler_allocate_capture.go b/pkg/http/handler_allocate_capture.go
@@ -20,6 +20,7 @@ func NewAllocateCaptureHandler(capturesRepo captures.Repository) Handler {
 }
 
 func (h AllocateCaptureHandler) Handle(c *gin.Context) {
+
 	var attemptedAllocation views.CaptureAllocation
 	if err := c.BindJSON(&attemptedAllocation); err != nil {
 		c.JSON(http.StatusBadRequest, views.MalformedPayload)
@@ -31,7 +32,7 @@ func (h AllocateCaptureHandler) Handle(c *gin.Context) {
 		return
 	}
 
-	allocation, err := h.capturesRepo.Allocate(c, attemptedAllocation.IdempotencyKey)
+	allocation, err := h.capturesRepo.Allocate(c.Request.Context(), attemptedAllocation.IdempotencyKey)
 
 	if err != nil {
 		zap.S().Errorw("failed to allocate a capture", "err", err.Error())
diff --git a/pkg/http/handler_readiness.go b/pkg/http/handler_readiness.go
@@ -18,7 +18,7 @@ func NewReadinessHandler(capturesRepo captures.Repository) Handler {
 
 func (h ReadinessHandler) Handle(c *gin.Context) {
 
-	ready := h.capturesRepo.Ready(c)
+	ready := h.capturesRepo.Ready(c.Request.Context())
 
 	if ready {
 		c.Status(http.StatusOK)
diff --git a/pkg/http/handler_record_capture.go b/pkg/http/handler_record_capture.go
@@ -35,7 +35,7 @@ func (h RecordCaptureHandler) Handle(c *gin.Context) {
 
 	allocation := adapters.CaptureRecordToAllocation(&capture)
 
-	if err := h.capturesRepo.Record(c, allocation); err != nil {
+	if err := h.capturesRepo.Record(c.Request.Context(), allocation); err != nil {
 
 		if err == captures.ErrConflictOrMissing {
 			c.JSON(http.StatusForbidden, views.CaptureIsCompleted)
diff --git a/pkg/http/server.go b/pkg/http/server.go
@@ -2,6 +2,7 @@ package http
 
 import (
 	"checkr.com/idempotent-requests/pkg/captures"
+	"checkr.com/idempotent-requests/pkg/tracing"
 	"context"
 	"github.com/gin-contrib/zap"
 	"github.com/gin-gonic/gin"
@@ -14,8 +15,8 @@ type Server struct {
 	Server *http.Server
 }
 
-func NewServer(records captures.Repository) *Server {
-	router := NewRouter(records)
+func NewServer(tracer tracing.Tracer, records captures.Repository) *Server {
+	router := NewRouter(tracer, records)
 
 	srv := &http.Server{
 		Addr:         ":8080",
@@ -26,10 +27,11 @@ func NewServer(records captures.Repository) *Server {
 	return &Server{Server: srv}
 }
 
-func NewRouter(captures captures.Repository) *gin.Engine {
+func NewRouter(tracer tracing.Tracer, captures captures.Repository) *gin.Engine {
 	gin.SetMode(gin.ReleaseMode)
 	router := gin.New()
 
+	tracer.Gin(router)
 	router.Use(ginzap.Ginzap(zap.S().Desugar(), time.RFC822, false))
 	router.Use(ginzap.RecoveryWithZap(zap.S().Desugar(), false))
 
diff --git a/pkg/mongodb/client.go b/pkg/mongodb/client.go
@@ -1,6 +1,7 @@
 package mongodb
 
 import (
+	"checkr.com/idempotent-requests/pkg/tracing"
 	"context"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
@@ -12,9 +13,13 @@ type Client struct {
 	Mongo *mongo.Client
 }
 
-func NewClient() *Client {
+func NewClient(tracer tracing.Tracer) *Client {
 	cfg := GetConfig()
-	client, err := mongo.NewClient(options.Client().ApplyURI(cfg.URI))
+	opts := options.Client().ApplyURI(cfg.URI)
+
+	opts = tracer.MongoDB(opts)
+
+	client, err := mongo.NewClient(opts)
 	if err != nil {
 		zap.S().Panic(err)
 	}
diff --git a/pkg/tracing/datadog.go b/pkg/tracing/datadog.go
@@ -1,12 +1,27 @@
 package tracing
 
 import (
+	"github.com/gin-gonic/gin"
 	"github.com/opentracing/opentracing-go"
+	"go.mongodb.org/mongo-driver/mongo/options"
+	gintrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/gin-gonic/gin"
+	mongotrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/go.mongodb.org/mongo-driver/mongo"
+	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/opentracer"
 	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
+	"os"
 )
 
 type DatadogTracer struct {
-	t opentracing.Tracer
+	enabled bool
+	t       opentracing.Tracer
+}
+
+func NewDatadogTracer(enabled bool) Tracer {
+	dt := DatadogTracer{
+		enabled: enabled,
+		t:       opentracer.New(tracer.WithServiceName(DDServiceName())),
+	}
+	return dt
 }
 
 func (dt DatadogTracer) OpentracingTracer() opentracing.Tracer {
@@ -16,3 +31,25 @@ func (dt DatadogTracer) OpentracingTracer() opentracing.Tracer {
 func (DatadogTracer) Stop() {
 	tracer.Stop()
 }
+
+func (dt DatadogTracer) MongoDB(clientOptions *options.ClientOptions) *options.ClientOptions {
+	if dt.enabled {
+		clientOptions.Monitor = mongotrace.NewMonitor(mongotrace.WithServiceName(DDServiceName()))
+	}
+	return clientOptions
+}
+
+func (dt DatadogTracer) Gin(router *gin.Engine) gin.IRoutes {
+	if dt.enabled {
+		router.Use(gintrace.Middleware(DDServiceName()))
+	}
+	return router
+}
+
+func DDServiceName() string {
+	s := os.Getenv("DD_SERVICE")
+	if len(s) == 0 {
+		s = "idempotent-requests"
+	}
+	return s
+}
diff --git a/pkg/tracing/factory.go b/pkg/tracing/factory.go
@@ -1,13 +1,10 @@
 package tracing
 
 import (
-	"checkr.com/idempotent-requests/pkg/util"
 	"go.uber.org/zap"
-	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/opentracer"
-	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
 )
 
-var tracerConstructors = map[string]func() Tracer{
+var tracerConstructors = map[string]func(enabled bool) Tracer{
 	Datadog: NewDatadogTracer,
 }
 
@@ -17,12 +14,5 @@ func NewTracer() Tracer {
 		zap.S().Panicf("not valid opentracing tracer implementation %s", cfg.TracerImplementation)
 	}
 
-	return tracerConstructors[cfg.TracerImplementation]()
-}
-
-func NewDatadogTracer() Tracer {
-	dt := DatadogTracer{
-		t: opentracer.New(tracer.WithServiceName(util.DDServiceName())),
-	}
-	return dt
+	return tracerConstructors[cfg.TracerImplementation](cfg.TracingEnabled)
 }
diff --git a/pkg/tracing/mock.go b/pkg/tracing/mock.go
@@ -0,0 +1,25 @@
+package tracing
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/opentracing/opentracing-go"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+type MockTracer struct{}
+
+func (MockTracer) OpentracingTracer() opentracing.Tracer {
+	return nil
+}
+
+func (MockTracer) Stop() {
+
+}
+
+func (MockTracer) MongoDB(options *options.ClientOptions) *options.ClientOptions {
+	return options
+}
+
+func (MockTracer) Gin(engine *gin.Engine) gin.IRoutes {
+	return engine
+}
diff --git a/pkg/tracing/tracer.go b/pkg/tracing/tracer.go
@@ -1,9 +1,19 @@
 package tracing
 
-import "github.com/opentracing/opentracing-go"
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/opentracing/opentracing-go"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
 
-// Tracer is a wrapping interface around opentracing.Tracer, which adds Stop method
+// Tracer is a wrapping interface around opentracing.Tracer with extra methods to abstract the tracer implementation
 type Tracer interface {
+	// OpentracingTracer provides a tracer instance, which implements opentracing interface
 	OpentracingTracer() opentracing.Tracer
+	// Stop shuts the tracer down
 	Stop()
+	// MongoDB injects an out-of-the-box instrumentation for MongoDB Client
+	MongoDB(*options.ClientOptions) *options.ClientOptions
+	// Gin injects an out-of-the-box instrumentation for Gin server
+	Gin(*gin.Engine) gin.IRoutes
 }
diff --git a/pkg/util/datadog.go b/pkg/util/datadog.go

Original file line number	Diff line number	Diff line change
`@@ -20,6 +20,7 @@ func NewAllocateCaptureHandler(capturesRepo captures.Repository) Handler {`
`20`	`20`	`}`
`21`	`21`
`22`	`22`	`func (h AllocateCaptureHandler) Handle(c *gin.Context) {`
	`23`	`+`
`23`	`24`	`var attemptedAllocation views.CaptureAllocation`
`24`	`25`	`if err := c.BindJSON(&attemptedAllocation); err != nil {`
`25`	`26`	`c.JSON(http.StatusBadRequest, views.MalformedPayload)`
`@@ -31,7 +32,7 @@ func (h AllocateCaptureHandler) Handle(c *gin.Context) {`
`31`	`32`	`return`
`32`	`33`	`}`
`33`	`34`
`34`		`- allocation, err := h.capturesRepo.Allocate(c, attemptedAllocation.IdempotencyKey)`
	`35`	`+ allocation, err := h.capturesRepo.Allocate(c.Request.Context(), attemptedAllocation.IdempotencyKey)`
`35`	`36`
`36`	`37`	`if err != nil {`
`37`	`38`	`zap.S().Errorw("failed to allocate a capture", "err", err.Error())`