1 files changed, 141 insertions, 0 deletions
diff --git a/tvix/nar-bridge/pkg/http/nar_put.go b/tvix/nar-bridge/pkg/http/nar_put.go
new file mode 100644
index 0000000000..fdfa20f9c3
--- /dev/null
+++ b/tvix/nar-bridge/pkg/http/nar_put.go
@@ -0,0 +1,141 @@
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"net/http"
+
+	castorev1pb "code.tvl.fyi/tvix/castore-go"
+	"code.tvl.fyi/tvix/nar-bridge/pkg/importer"
+	"github.com/go-chi/chi/v5"
+	mh "github.com/multiformats/go-multihash/core"
+	nixhash "github.com/nix-community/go-nix/pkg/hash"
+	"github.com/sirupsen/logrus"
+	log "github.com/sirupsen/logrus"
+)
+
+func registerNarPut(s *Server) {
+	s.handler.Put(narUrl, func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+
+		ctx := r.Context()
+
+		// parse the narhash sent in the request URL
+		narHashFromUrl, err := parseNarHashFromUrl(chi.URLParamFromCtx(ctx, "narhash"))
+		if err != nil {
+			log.WithError(err).WithField("url", r.URL).Error("unable to decode nar hash from url")
+			w.WriteHeader(http.StatusBadRequest)
+			_, err := w.Write([]byte("unable to decode nar hash from url"))
+			if err != nil {
+				log.WithError(err).Error("unable to write error message to client")
+			}
+
+			return
+		}
+
+		log := log.WithField("narhash_url", narHashFromUrl.SRIString())
+
+		directoriesUploader := importer.NewDirectoriesUploader(ctx, s.directoryServiceClient)
+		defer directoriesUploader.Done() //nolint:errcheck
+
+		rootNode, narSize, narSha256, err := importer.Import(
+			ctx,
+			// buffer the body by 10MiB
+			bufio.NewReaderSize(r.Body, 10*1024*1024),
+			importer.GenBlobUploaderCb(ctx, s.blobServiceClient),
+			func(directory *castorev1pb.Directory) ([]byte, error) {
+				return directoriesUploader.Put(directory)
+			},
+		)
+
+		if err != nil {
+			log.Errorf("error during NAR import: %v", err)
+			w.WriteHeader(http.StatusInternalServerError)
+			_, err := w.Write([]byte(fmt.Sprintf("error during NAR import: %v", err)))
+			if err != nil {
+				log.WithError(err).Errorf("unable to write error message to client")
+			}
+
+			return
+		}
+
+		log.Debug("closing the stream")
+
+		// Close the directories uploader
+		directoriesPutResponse, err := directoriesUploader.Done()
+		if err != nil {
+			log.WithError(err).Error("error during directory upload")
+			w.WriteHeader(http.StatusBadRequest)
+			_, err := w.Write([]byte("error during directory upload"))
+			if err != nil {
+				log.WithError(err).Errorf("unable to write error message to client")
+			}
+
+			return
+		}
+		// If we uploaded directories (so directoriesPutResponse doesn't return null),
+		// the RootDigest field in directoriesPutResponse should match the digest
+		// returned in the PathInfo struct returned by the `Import` call.
+		// This check ensures the server-side came up with the same root hash.
+
+		if directoriesPutResponse != nil {
+			rootDigestPathInfo := rootNode.GetDirectory().GetDigest()
+			rootDigestDirectoriesPutResponse := directoriesPutResponse.GetRootDigest()
+
+			log := log.WithFields(logrus.Fields{
+				"root_digest_pathinfo":             rootDigestPathInfo,
+				"root_digest_directories_put_resp": rootDigestDirectoriesPutResponse,
+			})
+			if !bytes.Equal(rootDigestPathInfo, rootDigestDirectoriesPutResponse) {
+				log.Errorf("returned root digest doesn't match what's calculated")
+
+				w.WriteHeader(http.StatusBadRequest)
+				_, err := w.Write([]byte("error in root digest calculation"))
+				if err != nil {
+					log.WithError(err).Error("unable to write error message to client")
+				}
+
+				return
+			}
+		}
+
+		// Compare the nar hash specified in the URL with the one that has been
+		// calculated while processing the NAR file.
+		narHash, err := nixhash.FromHashTypeAndDigest(mh.SHA2_256, narSha256)
+		if err != nil {
+			panic("must parse nixbase32")
+		}
+
+		if !bytes.Equal(narHashFromUrl.Digest(), narHash.Digest()) {
+			log := log.WithFields(logrus.Fields{
+				"narhash_received_sha256": narHash.SRIString(),
+				"narsize":                 narSize,
+			})
+			log.Error("received bytes don't match narhash from URL")
+
+			w.WriteHeader(http.StatusBadRequest)
+			_, err := w.Write([]byte("received bytes don't match narHash specified in URL"))
+			if err != nil {
+				log.WithError(err).Errorf("unable to write error message to client")
+			}
+
+			return
+		}
+
+		// Insert the partial pathinfo structs into our lookup map,
+		// so requesting the NAR file will be possible.
+		// The same  might exist already, but it'll have the same contents (so
+		// replacing will be a no-op), except maybe the root node Name field value, which
+		// is safe to ignore (as not part of the NAR).
+		s.narDbMu.Lock()
+		s.narDb[narHash.SRIString()] = &narData{
+			rootNode: rootNode,
+			narSize:  narSize,
+		}
+		s.narDbMu.Unlock()
+
+		// Done!
+	})
+
+}