fix(ipns): fail fast and fix rpc encoding

gateway.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	gopath "path"
 
@@ -28,7 +29,9 @@ import (
 	"github.com/ipld/go-ipld-prime"
 	"github.com/ipld/go-ipld-prime/node/basicnode"
 	"github.com/ipld/go-ipld-prime/schema"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/libp2p/go-libp2p/core/routing"
+	mc "github.com/multiformats/go-multicodec"
 )
 
 type bifrostGateway struct {
@@ -112,7 +115,19 @@ func (api *bifrostGateway) GetBlock(ctx context.Context, c cid.Cid) (blocks.Bloc
 }
 
 func (api *bifrostGateway) GetIPNSRecord(ctx context.Context, c cid.Cid) ([]byte, error) {
-	return api.routing.GetValue(ctx, "/ipns/"+c.String())
+	// Fails fast if the CID is not an encoded Libp2p Key, avoids wasteful
+	// round trips to the remote routing provider.
+	if mc.Code(c.Type()) != mc.Libp2pKey {
+		return nil, errors.New("provided cid is not an encoded libp2p key")
+	}
+
+	// The value store expects the key itself to be multihash.
+	id, err := peer.FromCid(c)
+	if err != nil {
+		return nil, err
+	}
+
+	return api.routing.GetValue(ctx, "/ipns/"+string(id))
 }
 
 func (api *bifrostGateway) GetDNSLinkRecord(ctx context.Context, hostname string) (ifacepath.Path, error) {

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/ipld/go-codec-dagpb v1.5.0
 	github.com/ipld/go-ipld-prime v0.19.0
 	github.com/libp2p/go-libp2p v0.23.4
+	github.com/multiformats/go-multicodec v0.7.0
 	github.com/prometheus/client_golang v1.14.0
 	github.com/spf13/cobra v1.6.1
 	github.com/stretchr/testify v1.8.1
@@ -85,7 +86,6 @@ require (
 	github.com/multiformats/go-multiaddr v0.8.0 // indirect
 	github.com/multiformats/go-multiaddr-dns v0.3.1 // indirect
 	github.com/multiformats/go-multibase v0.1.1 // indirect
-	github.com/multiformats/go-multicodec v0.7.0 // indirect
 	github.com/multiformats/go-multihash v0.2.1 // indirect
 	github.com/multiformats/go-varint v0.0.7 // indirect
 	github.com/opencontainers/runtime-spec v1.0.3-0.20211123151946-c2389c3cb60a // indirect

routing.go

@@ -1,8 +1,11 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"encoding/base64"
+	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
@@ -95,18 +98,33 @@ func (ps *proxyRouting) fetch(ctx context.Context, key string) ([]byte, error) {
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("unexpected status from remote gateway: %s", resp.Status)
+		return nil, fmt.Errorf("routing/get RPC returned unexpected status: %s", resp.Status)
 	}
 
 	rb, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
 
-	b64 := string(rb)
-	b64 = strings.TrimSpace(b64)
-	b64 = strings.TrimPrefix(b64, "\"")
-	b64 = strings.TrimSuffix(b64, "\"")
+	parts := bytes.Split(bytes.TrimSpace(rb), []byte("\n"))
+	var b64 string
+
+	for _, part := range parts {
+		var evt routing.QueryEvent
+		err = json.Unmarshal(part, &evt)
+		if err != nil {
+			return nil, fmt.Errorf("routing/get RPC response cannot be parsed: %w", err)
+		}
+
+		if evt.Type == routing.Value {
+			b64 = evt.Extra
+			break
+		}
+	}
+
+	if b64 == "" {
+		return nil, errors.New("routing/get RPC returned no value")
+	}
 
 	rb, err = base64.StdEncoding.DecodeString(b64)
 	if err != nil {