chore(tvix/nar-bridge): move to nar-bridge-go

Make some space for the rust implementation.

Change-Id: I924dc1657be10abe5a11951c3b9de50bae06db19
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11662
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: yuka <yuka@yuka.dev>

tvix/nar-bridge-go/pkg/http/server.go

@@ -0,0 +1,119 @@
+package http
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	castorev1pb "code.tvl.fyi/tvix/castore-go"
+	storev1pb "code.tvl.fyi/tvix/store-go"
+	"github.com/go-chi/chi/middleware"
+	"github.com/go-chi/chi/v5"
+	log "github.com/sirupsen/logrus"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+)
+
+type Server struct {
+	srv     *http.Server
+	handler chi.Router
+
+	directoryServiceClient castorev1pb.DirectoryServiceClient
+	blobServiceClient      castorev1pb.BlobServiceClient
+	pathInfoServiceClient  storev1pb.PathInfoServiceClient
+
+	// When uploading NAR files to a HTTP binary cache, the .nar
+	// files are uploaded before the .narinfo files.
+	// We need *both* to be able to fully construct a PathInfo object.
+	// Keep a in-memory map of narhash(es) (in SRI) to (unnamed) root node and nar
+	// size.
+	// This is necessary until we can ask a PathInfoService for a node with a given
+	// narSha256.
+	narDbMu sync.Mutex
+	narDb   map[string]*narData
+}
+
+type narData struct {
+	rootNode *castorev1pb.Node
+	narSize  uint64
+}
+
+func New(
+	directoryServiceClient castorev1pb.DirectoryServiceClient,
+	blobServiceClient castorev1pb.BlobServiceClient,
+	pathInfoServiceClient storev1pb.PathInfoServiceClient,
+	enableAccessLog bool,
+	priority int,
+) *Server {
+	r := chi.NewRouter()
+	r.Use(func(h http.Handler) http.Handler {
+		return otelhttp.NewHandler(h, "http.request")
+	})
+
+	if enableAccessLog {
+		r.Use(middleware.Logger)
+	}
+
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		_, err := w.Write([]byte("nar-bridge"))
+		if err != nil {
+			log.Errorf("Unable to write response: %v", err)
+		}
+	})
+
+	r.Get("/nix-cache-info", func(w http.ResponseWriter, r *http.Request) {
+		_, err := w.Write([]byte(fmt.Sprintf("StoreDir: /nix/store\nWantMassQuery: 1\nPriority: %d\n", priority)))
+		if err != nil {
+			log.Errorf("Unable to write response: %v", err)
+		}
+	})
+
+	s := &Server{
+		handler:                r,
+		directoryServiceClient: directoryServiceClient,
+		blobServiceClient:      blobServiceClient,
+		pathInfoServiceClient:  pathInfoServiceClient,
+		narDb:                  make(map[string]*narData),
+	}
+
+	registerNarPut(s)
+	registerNarinfoPut(s)
+
+	registerNarinfoGet(s)
+	registerNarGet(s)
+
+	return s
+}
+
+func (s *Server) Shutdown(ctx context.Context) error {
+	return s.srv.Shutdown(ctx)
+}
+
+// ListenAndServer starts the webserver, and waits for it being closed or
+// shutdown, after which it'll return ErrServerClosed.
+func (s *Server) ListenAndServe(addr string) error {
+	s.srv = &http.Server{
+		Handler:      s.handler,
+		ReadTimeout:  500 * time.Second,
+		WriteTimeout: 500 * time.Second,
+		IdleTimeout:  500 * time.Second,
+	}
+
+	var listener net.Listener
+	var err error
+
+	// check addr. If it contains slashes, assume it's a unix domain socket.
+	if strings.Contains(addr, "/") {
+		listener, err = net.Listen("unix", addr)
+	} else {
+		listener, err = net.Listen("tcp", addr)
+	}
+	if err != nil {
+		return fmt.Errorf("unable to listen on %v: %w", addr, err)
+	}
+
+	return s.srv.Serve(listener)
+}