vendor: update buildkit to opentelemetry support

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/moby/buildkit/util/tracing/detect/otlp.go

@@ -0,0 +1,45 @@
+package detect
+
+import (
+	"context"
+	"os"
+
+	"github.com/pkg/errors"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+)
+
+func init() {
+	Register("otlp", otlpExporter, 10)
+}
+
+func otlpExporter() (sdktrace.SpanExporter, error) {
+	set := os.Getenv("OTEL_TRACES_EXPORTER") == "otpl" || os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT") != "" || os.Getenv("OTEL_EXPORTER_OTLP_TRACES_ENDPOINT") != ""
+	if !set {
+		return nil, nil
+	}
+
+	proto := os.Getenv("OTEL_EXPORTER_OTLP_TRACES_PROTOCOL")
+	if proto == "" {
+		proto = os.Getenv("OTEL_EXPORTER_OTLP_PROTOCOL")
+	}
+	if proto == "" {
+		proto = "grpc"
+	}
+
+	var c otlptrace.Client
+
+	switch proto {
+	case "grpc":
+		c = otlptracegrpc.NewClient()
+	case "http/protobuf":
+		c = otlptracehttp.NewClient()
+	// case "http/json": // unsupported by library
+	default:
+		return nil, errors.Errorf("unsupported otlp protocol %v", proto)
+	}
+
+	return otlptrace.New(context.Background(), c)
+}