Add OpenTelemetry Support

go.mod

@@ -1,5 +1,10 @@
 module github.com/graph-gophers/graphql-go
 
-require github.com/opentracing/opentracing-go v1.1.0
+require (
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/opentracing/opentracing-go v1.2.0
+	go.opentelemetry.io/otel v1.3.0
+	go.opentelemetry.io/otel/trace v1.3.0
+)
 
 go 1.13

go.sum

@@ -1,2 +1,24 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.1/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.2 h1:ahHml/yUpnlb96Rp8HCvtYVPY8ZYpxq3g7UYchIYwbs=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.0/go.mod h1:YkVgnZu1ZjjL7xTxrfm/LLZBfkhTqSR1ydtm6jTKKwI=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/opentracing/opentracing-go v1.1.0 h1:pWlfV3Bxv7k65HYwkikxat0+s3pV4bsqf19k25Ur8rU=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
+github.com/opentracing/opentracing-go v1.2.0 h1:uEJPy/1a5RIPAJ0Ov+OIO8OxWu77jEv+1B0VhjKrZUs=
+github.com/opentracing/opentracing-go v1.2.0/go.mod h1:GxEUsuufX4nBwe+T+Wl9TAgYrxe9dPLANfrWvHYVTgc=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+go.opentelemetry.io/otel v1.3.0 h1:APxLf0eiBwLl+SOXiJJCVYzA1OOJNyAoV8C5RNRyy7Y=
+go.opentelemetry.io/otel v1.3.0/go.mod h1:PWIKzi6JCp7sM0k9yZ43VX+T345uNbAkDKwHVjb2PTs=
+go.opentelemetry.io/otel/trace v1.3.0 h1:doy8Hzb1RJ+I3yFhtDmwNc7tIyw1tNMOIsyPzp1NOGY=
+go.opentelemetry.io/otel/trace v1.3.0/go.mod h1:c/VDhno8888bvQYmbYLqe41/Ldmr/KKunbvWM4/fEjk=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

trace/opentel/opentelemetry_tracer.go

@@ -0,0 +1,92 @@
+package trace
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/graph-gophers/graphql-go/errors"
+	"github.com/graph-gophers/graphql-go/introspection"
+	"github.com/graph-gophers/graphql-go/trace"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	oteltrace "go.opentelemetry.io/otel/trace"
+)
+
+// DefaultOpenTelemetryTracer creates a tracer using a default name
+func DefaultOpenTelemetryTracer() trace.Tracer {
+	return &OpenTelemetryTracer{
+		Tracer: otel.Tracer("graphql-go"),
+	}
+}
+
+// OpenTelemetryTracer is an OpenTelemetry implementation for graphql-go. Set the Tracer
+// property to your tracer instance as required.
+type OpenTelemetryTracer struct {
+	Tracer oteltrace.Tracer
+}
+
+func (t *OpenTelemetryTracer) TraceQuery(ctx context.Context, queryString string, operationName string, variables map[string]interface{}, varTypes map[string]*introspection.Type) (context.Context, trace.TraceQueryFinishFunc) {
+	spanCtx, span := t.Tracer.Start(ctx, "GraphQL Request")
+
+	var attributes []attribute.KeyValue
+	attributes = append(attributes, attribute.String("graphql.query", queryString))
+	if operationName != "" {
+		attributes = append(attributes, attribute.String("graphql.operationName", operationName))
+	}
+	if len(variables) != 0 {
+		attributes = append(attributes, attribute.String("graphql.variables", fmt.Sprintf("%v", variables)))
+	}
+	span.SetAttributes(attributes...)
+
+	return spanCtx, func(errs []*errors.QueryError) {
+		if len(errs) > 0 {
+			msg := errs[0].Error()
+			if len(errs) > 1 {
+				msg += fmt.Sprintf(" (and %d more errors)", len(errs)-1)
+			}
+
+			span.SetStatus(codes.Error, msg)
+		}
+		span.End()
+	}
+}
+
+func (t *OpenTelemetryTracer) TraceField(ctx context.Context, label, typeName, fieldName string, trivial bool, args map[string]interface{}) (context.Context, trace.TraceFieldFinishFunc) {
+	if trivial {
+		return ctx, func(*errors.QueryError) {}
+	}
+
+	var attributes []attribute.KeyValue
+
+	spanCtx, span := t.Tracer.Start(ctx, fmt.Sprintf("Field: %v", label))
+	attributes = append(attributes, attribute.String("graphql.type", typeName))
+	attributes = append(attributes, attribute.String("graphql.field", fieldName))
+	for name, value := range args {
+		attributes = append(attributes, attribute.String("graphql.args."+name, fmt.Sprintf("%v", value)))
+	}
+	span.SetAttributes(attributes...)
+
+	return spanCtx, func(err *errors.QueryError) {
+		if err != nil {
+			span.SetStatus(codes.Error, err.Error())
+		}
+		span.End()
+	}
+}
+
+func (t *OpenTelemetryTracer) TraceValidation(ctx context.Context) trace.TraceValidationFinishFunc {
+	_, span := t.Tracer.Start(ctx, "GraphQL Validate")
+
+	return func(errs []*errors.QueryError) {
+		if len(errs) > 0 {
+			msg := errs[0].Error()
+			if len(errs) > 1 {
+				msg += fmt.Sprintf(" (and %d more errors)", len(errs)-1)
+			}
+			span.SetStatus(codes.Error, msg)
+		}
+		span.End()
+	}
+}