ability to override TracerProvider

extra/redisotel/go.mod

@@ -9,6 +9,6 @@ replace github.com/go-redis/redis/extra/rediscmd/v8 => ../rediscmd
 require (
 	github.com/go-redis/redis/extra/rediscmd/v8 v8.11.4
 	github.com/go-redis/redis/v8 v8.11.4
-	go.opentelemetry.io/otel v1.0.0
-	go.opentelemetry.io/otel/trace v1.0.0
+	go.opentelemetry.io/otel v1.3.0
+	go.opentelemetry.io/otel/trace v1.3.0
 )

extra/redisotel/go.sum

@@ -8,6 +8,11 @@ github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cu
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9 h1:hsms1Qyu0jgnwNXIxa+/V/PDsU6CfLf6CNO8H7IWoS4=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
+github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.1 h1:DX7uPQ4WgAWfoh+NGGlbJQswnYIVvz0SRlLS3rPZQDA=
+github.com/go-logr/logr v1.2.1/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.0 h1:j4LrlVXgrbIWO83mmQUnK0Hi+YnbD+vzrE1z/EphbFE=
+github.com/go-logr/stdr v1.2.0/go.mod h1:YkVgnZu1ZjjL7xTxrfm/LLZBfkhTqSR1ydtm6jTKKwI=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
@@ -31,24 +36,25 @@ github.com/nxadm/tail v1.4.8 h1:nPr65rt6Y5JFSKQO7qToXr7pePgD6Gwiw05lkbyAQTE=
 github.com/nxadm/tail v1.4.8/go.mod h1:+ncqLTQzXmGhMZNUePPaPqPvBxHAIsmXswZKocGu+AU=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.12.1/go.mod h1:zj2OWP4+oCPe1qIXoGWkgMRwljMUYCdkwsT2108oapk=
-github.com/onsi/ginkgo v1.16.4 h1:29JGrr5oVBm5ulCWet69zQkzWipVXIol6ygQUe/EzNc=
 github.com/onsi/ginkgo v1.16.4/go.mod h1:dX+/inL/fNMqNlz0e9LfyB9TswhZpCVdJM/Z6Vvnwo0=
+github.com/onsi/ginkgo v1.16.5 h1:8xi0RTUf59SOSfEtZMvwTvXYMzG4gV23XVHOZiXNtnE=
 github.com/onsi/ginkgo v1.16.5/go.mod h1:+E8gABHa3K6zRBolWtd+ROzc/U5bkGt0FwiG042wbpU=
 github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
-github.com/onsi/gomega v1.16.0 h1:6gjqkI8iiRHMvdccRJM8rVKjCWk6ZIm6FTm3ddIe4/c=
 github.com/onsi/gomega v1.16.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
+github.com/onsi/gomega v1.17.0 h1:9Luw4uT5HTjHTN8+aNcSThgH1vdXnmdJ8xIfZ4wyTRE=
+github.com/onsi/gomega v1.17.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 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 v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-go.opentelemetry.io/otel v1.0.0 h1:qTTn6x71GVBvoafHK/yaRUmFzI4LcONZD0/kXxl5PHI=
-go.opentelemetry.io/otel v1.0.0/go.mod h1:AjRVh9A5/5DE7S+mZtTR6t8vpKKryam+0lREnfmS4cg=
-go.opentelemetry.io/otel/trace v1.0.0 h1:TSBr8GTEtKevYMG/2d21M989r5WJYVimhTHBKVEZuh4=
-go.opentelemetry.io/otel/trace v1.0.0/go.mod h1:PXTWqayeFUlJV1YDNhsJYB184+IvAH814St6o6ajzIs=
+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/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=

extra/redisotel/redisotel.go

@@ -6,42 +6,57 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
 	"go.opentelemetry.io/otel/trace"
 
 	"github.com/go-redis/redis/extra/rediscmd/v8"
 	"github.com/go-redis/redis/v8"
 )
 
-var tracer = otel.Tracer("github.com/go-redis/redis")
+const (
+	// todo: consider using the full module path "github.com/go-redis/redis/extra/redisotel"
+	defaultTracerName = "github.com/go-redis/redis"
+)
 
-type TracingHook struct{}
+type TracingHook struct {
+	tracer trace.Tracer
+}
 
-var _ redis.Hook = (*TracingHook)(nil)
+func NewTracingHook(opts ...Option) *TracingHook {
+	cfg := &config{
+		tp: otel.GetTracerProvider(),
+	}
+	for _, opt := range opts {
+		opt.apply(cfg)
+	}
 
-func NewTracingHook() *TracingHook {
-	return new(TracingHook)
+	tracer := cfg.tp.Tracer(
+		defaultTracerName,
+		// todo: consider adding a version
+		// trace.WithInstrumentationVersion("semver:8.11.4"),
+	)
+	return &TracingHook{tracer: tracer}
 }
 
-func (TracingHook) BeforeProcess(ctx context.Context, cmd redis.Cmder) (context.Context, error) {
+func (th *TracingHook) BeforeProcess(ctx context.Context, cmd redis.Cmder) (context.Context, error) {
 	if !trace.SpanFromContext(ctx).IsRecording() {
 		return ctx, nil
 	}
 
-	attrs := []attribute.KeyValue{
-		attribute.String("db.system", "redis"),
-		attribute.String("db.statement", rediscmd.CmdString(cmd)),
-	}
 	opts := []trace.SpanStartOption{
 		trace.WithSpanKind(trace.SpanKindClient),
-		trace.WithAttributes(attrs...),
+		trace.WithAttributes(
+			semconv.DBSystemRedis,
+			semconv.DBStatementKey.String(rediscmd.CmdString(cmd)),
+		),
 	}
 
-	ctx, _ = tracer.Start(ctx, cmd.FullName(), opts...)
+	ctx, _ = th.tracer.Start(ctx, cmd.FullName(), opts...)
 
 	return ctx, nil
 }
 
-func (TracingHook) AfterProcess(ctx context.Context, cmd redis.Cmder) error {
+func (th *TracingHook) AfterProcess(ctx context.Context, cmd redis.Cmder) error {
 	span := trace.SpanFromContext(ctx)
 	if err := cmd.Err(); err != nil {
 		recordError(ctx, span, err)
@@ -50,29 +65,28 @@ func (TracingHook) AfterProcess(ctx context.Context, cmd redis.Cmder) error {
 	return nil
 }
 
-func (TracingHook) BeforeProcessPipeline(ctx context.Context, cmds []redis.Cmder) (context.Context, error) {
+func (th *TracingHook) BeforeProcessPipeline(ctx context.Context, cmds []redis.Cmder) (context.Context, error) {
 	if !trace.SpanFromContext(ctx).IsRecording() {
 		return ctx, nil
 	}
 
 	summary, cmdsString := rediscmd.CmdsString(cmds)
 
-	attrs := []attribute.KeyValue{
-		attribute.String("db.system", "redis"),
-		attribute.Int("db.redis.num_cmd", len(cmds)),
-		attribute.String("db.statement", cmdsString),
-	}
 	opts := []trace.SpanStartOption{
 		trace.WithSpanKind(trace.SpanKindClient),
-		trace.WithAttributes(attrs...),
+		trace.WithAttributes(
+			semconv.DBSystemRedis,
+			semconv.DBStatementKey.String(cmdsString),
+			attribute.Int("db.redis.num_cmd", len(cmds)),
+		),
 	}
 
-	ctx, _ = tracer.Start(ctx, "pipeline "+summary, opts...)
+	ctx, _ = th.tracer.Start(ctx, "pipeline "+summary, opts...)
 
 	return ctx, nil
 }
 
-func (TracingHook) AfterProcessPipeline(ctx context.Context, cmds []redis.Cmder) error {
+func (th *TracingHook) AfterProcessPipeline(ctx context.Context, cmds []redis.Cmder) error {
 	span := trace.SpanFromContext(ctx)
 	if err := cmds[0].Err(); err != nil {
 		recordError(ctx, span, err)
@@ -87,3 +101,28 @@ func recordError(ctx context.Context, span trace.Span, err error) {
 		span.SetStatus(codes.Error, err.Error())
 	}
 }
+
+type config struct {
+	tp trace.TracerProvider
+}
+
+// Option specifies instrumentation configuration options.
+type Option interface {
+	apply(*config)
+}
+
+type optionFunc func(*config)
+
+func (o optionFunc) apply(c *config) {
+	o(c)
+}
+
+// WithTracerProvider specifies a tracer provider to use for creating a tracer.
+// If none is specified, the global provider is used.
+func WithTracerProvider(provider trace.TracerProvider) Option {
+	return optionFunc(func(cfg *config) {
+		if provider != nil {
+			cfg.tp = provider
+		}
+	})
+}

extra/redisotel/redisotel_test.go

@@ -0,0 +1,37 @@
+package redisotel_test
+
+import (
+	"testing"
+
+	"github.com/go-redis/redis/extra/redisotel/v8"
+	"github.com/go-redis/redis/v8"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/trace"
+)
+
+func TestNew(t *testing.T) {
+	// this also functions as a compile-time test that the
+	// TracingHook conforms to the Hook interface
+	var _ redis.Hook = redisotel.NewTracingHook()
+}
+
+type providerFunc func(name string, opts ...trace.TracerOption) trace.Tracer
+
+func (fn providerFunc) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
+	return fn(name, opts...)
+}
+
+func TestNewWithTracerProvider(t *testing.T) {
+	invoked := false
+
+	tp := providerFunc(func(name string, opts ...trace.TracerOption) trace.Tracer {
+		invoked = true
+		return otel.GetTracerProvider().Tracer(name, opts...)
+	})
+
+	_ = redisotel.NewTracingHook(redisotel.WithTracerProvider(tp))
+
+	if !invoked {
+		t.Fatalf("did not call custom TraceProvider")
+	}
+}