2 files changed, 180 insertions, 0 deletions
diff --git a/tvix/nar-bridge-go/cmd/nar-bridge-http/main.go b/tvix/nar-bridge-go/cmd/nar-bridge-http/main.go
new file mode 100644
index 000000000000..cf2aaf4901b2
--- /dev/null
+++ b/tvix/nar-bridge-go/cmd/nar-bridge-http/main.go
@@ -0,0 +1,93 @@
+package main
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"runtime/debug"
+	"time"
+
+	"github.com/alecthomas/kong"
+
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+
+	castorev1pb "code.tvl.fyi/tvix/castore-go"
+	narBridgeHttp "code.tvl.fyi/tvix/nar-bridge-go/pkg/http"
+	storev1pb "code.tvl.fyi/tvix/store-go"
+	log "github.com/sirupsen/logrus"
+)
+
+// `help:"Expose a tvix-store gRPC Interface as HTTP NAR/NARinfo"`
+var cli struct {
+	LogLevel        string `enum:"trace,debug,info,warn,error,fatal,panic" help:"The log level to log with" default:"info"`
+	ListenAddr      string `name:"listen-addr" help:"The address this service listens on" type:"string" default:"[::]:9000"`                    //nolint:lll
+	EnableAccessLog bool   `name:"access-log" help:"Enable access logging" type:"bool" default:"true" negatable:""`                             //nolint:lll
+	StoreAddr       string `name:"store-addr" help:"The address to the tvix-store RPC interface this will connect to" default:"localhost:8000"` //nolint:lll
+	EnableOtlp      bool   `name:"otlp" help:"Enable OpenTelemetry for logs, spans, and metrics" default:"true"`                                //nolint:lll
+}
+
+func main() {
+	_ = kong.Parse(&cli)
+
+	logLevel, err := log.ParseLevel(cli.LogLevel)
+	if err != nil {
+		log.Panic("invalid log level")
+		return
+	}
+	log.SetLevel(logLevel)
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer stop()
+
+	if cli.EnableOtlp {
+		buildInfo, ok := debug.ReadBuildInfo()
+		if !ok {
+			log.Fatal("failed to read build info")
+		}
+
+		shutdown, err := setupOpenTelemetry(ctx, "nar-bridge-http", buildInfo.Main.Version)
+		if err != nil {
+			log.WithError(err).Fatal("failed to setup OpenTelemetry")
+		}
+		defer shutdown(context.Background())
+	}
+
+	// connect to tvix-store
+	log.Debugf("Dialing to %v", cli.StoreAddr)
+	conn, err := grpc.DialContext(ctx, cli.StoreAddr,
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithStatsHandler(otelgrpc.NewClientHandler()),
+	)
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+
+	s := narBridgeHttp.New(
+		castorev1pb.NewDirectoryServiceClient(conn),
+		castorev1pb.NewBlobServiceClient(conn),
+		storev1pb.NewPathInfoServiceClient(conn),
+		cli.EnableAccessLog,
+		30,
+	)
+
+	log.Printf("Starting nar-bridge-http at %v", cli.ListenAddr)
+	go s.ListenAndServe(cli.ListenAddr)
+
+	// listen for the interrupt signal.
+	<-ctx.Done()
+
+	// Restore default behaviour on the interrupt signal
+	stop()
+	log.Info("Received Signal, shutting down, press Ctl+C again to force.")
+
+	timeoutCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	if err := s.Shutdown(timeoutCtx); err != nil {
+		log.WithError(err).Warn("failed to shutdown")
+		os.Exit(1)
+	}
+}
diff --git a/tvix/nar-bridge-go/cmd/nar-bridge-http/otel.go b/tvix/nar-bridge-go/cmd/nar-bridge-http/otel.go
new file mode 100644
index 000000000000..c446c6ec1a14
--- /dev/null
+++ b/tvix/nar-bridge-go/cmd/nar-bridge-http/otel.go
@@ -0,0 +1,87 @@
+package main
+
+import (
+	"context"
+	"errors"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+)
+
+func setupOpenTelemetry(ctx context.Context, serviceName, serviceVersion string) (func(context.Context) error, error) {
+	var shutdownFuncs []func(context.Context) error
+	shutdown := func(ctx context.Context) error {
+		var err error
+		for _, fn := range shutdownFuncs {
+			err = errors.Join(err, fn(ctx))
+		}
+		shutdownFuncs = nil
+		return err
+	}
+
+	res, err := resource.Merge(
+		resource.Default(),
+		resource.NewWithAttributes(
+			semconv.SchemaURL,
+			semconv.ServiceName(serviceName),
+			semconv.ServiceVersion(serviceVersion),
+		),
+	)
+	if err != nil {
+		return nil, errors.Join(err, shutdown(ctx))
+	}
+
+	prop := propagation.NewCompositeTextMapPropagator(
+		propagation.TraceContext{},
+		propagation.Baggage{},
+	)
+	otel.SetTextMapPropagator(prop)
+
+	tracerProvider, err := newTraceProvider(ctx, res)
+	if err != nil {
+		return nil, errors.Join(err, shutdown(ctx))
+	}
+	shutdownFuncs = append(shutdownFuncs, tracerProvider.Shutdown)
+	otel.SetTracerProvider(tracerProvider)
+
+	meterProvider, err := newMeterProvider(ctx, res)
+	if err != nil {
+		return nil, errors.Join(err, shutdown(ctx))
+	}
+	shutdownFuncs = append(shutdownFuncs, meterProvider.Shutdown)
+	otel.SetMeterProvider(meterProvider)
+
+	return shutdown, nil
+}
+
+func newTraceProvider(ctx context.Context, res *resource.Resource) (*trace.TracerProvider, error) {
+	traceExporter, err := otlptracegrpc.New(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	traceProvider := trace.NewTracerProvider(
+		trace.WithBatcher(traceExporter),
+		trace.WithResource(res),
+	)
+	return traceProvider, nil
+}
+
+func newMeterProvider(ctx context.Context, res *resource.Resource) (*metric.MeterProvider, error) {
+	metricExporter, err := otlpmetricgrpc.New(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	meterProvider := metric.NewMeterProvider(
+		metric.WithResource(res),
+		metric.WithReader(metric.NewPeriodicReader(metricExporter)),
+	)
+	return meterProvider, nil
+}