refactor: IPNS_RECORD_GATEWAY_URL

Ensures IPNS_RECORD_GATEWAY_URL is prefered, then we fallback to
PROXY_GATEWAY_URL, and finally KUBO_RPC_URL

docs/environment-variables.md

@@ -59,15 +59,15 @@ in the near feature.
 Single URL or a comma separated list of Gateway endpoints that support `?format=block|car|ipns-record`
 responses. Either this variable or `STRN_ORCHESTRATOR_URL` must be set.
 
-If this gateway does not support `application/vnd.ipfs.ipns-record`, you can use `IPNS_RECORD_GATEWAY`
+If this gateway does not support `application/vnd.ipfs.ipns-record`, you can use `IPNS_RECORD_GATEWAY_URL`
 to override the gateway address from which to retrieve IPNS Records from.
 
-### `IPNS_RECORD_GATEWAY`
+### `IPNS_RECORD_GATEWAY_URL`
 
 Single URL or a comma separated list of Gateway endpoints that support requests for `application/vnd.ipfs.ipns-record`.
 This is used for IPNS Record routing.
 
-`IPNS_RECORD_GATEWAY` also supports [Routing V1 HTTP API](https://specs.ipfs.tech/routing/http-routing-v1/)
+`IPNS_RECORD_GATEWAY_URL` also supports [Routing V1 HTTP API](https://specs.ipfs.tech/routing/http-routing-v1/)
 for IPNS Record routing ([IPIP-379](https://specs.ipfs.tech/ipips/ipip-0379/)). To use it, the provided URL must end with `/routing/v1`.
 
 If not set, the IPNS records will be fetched from `KUBO_RPC_URL`.

handlers.go

@@ -70,15 +70,15 @@ func withRequestLogger(next http.Handler) http.Handler {
 	})
 }
 
-func makeGatewayHandler(bs bstore.Blockstore, kuboRPC, gatewayURLs []string, port int, blockCacheSize int, cdns *cachedDNS, useGraphBackend bool) (*http.Server, error) {
+func makeGatewayHandler(bs bstore.Blockstore, kuboRPC, ipnsRecordGateways []string, port int, blockCacheSize int, cdns *cachedDNS, useGraphBackend bool) (*http.Server, error) {
 	// Sets up the routing system, which will proxy the IPNS routing requests to the given gateway or kubo RPC.
 	var routing routing.ValueStore
-	if len(gatewayURLs) != 0 {
-		routing = newProxyRouting(gatewayURLs, cdns)
+	if len(ipnsRecordGateways) != 0 {
+		routing = newProxyRouting(ipnsRecordGateways, cdns)
 	} else if len(kuboRPC) != 0 {
 		routing = newRPCProxyRouting(kuboRPC, cdns)
 	} else {
-		return nil, errors.New("kubo rpc or gateway urls must be provided in order to delegate routing")
+		return nil, errors.New("either KUBO_RPC_URL, IPNS_RECORD_GATEWAY_URL or PROXY_GATEWAY_URL with support for application/vnd.ipfs.ipns-record must be provided in order to delegate IPNS routing")
 	}
 
 	// Sets up a cache to store blocks in

main.go

@@ -32,7 +32,7 @@ func main() {
 
 const (
 	EnvKuboRPC           = "KUBO_RPC_URL"
-	EnvIPNSRecordGateway = "IPNS_RECORD_GATEWAY"
+	EnvIPNSRecordGateway = "IPNS_RECORD_GATEWAY_URL"
 	EnvBlockCacheSize    = "BLOCK_CACHE_SIZE"
 	EnvGraphBackend      = "GRAPH_BACKEND"
 	RequestIDHeader      = "X-Bfid"
@@ -108,8 +108,15 @@ See documentation at: https://github.com/ipfs/bifrost-gateway/#readme`,
 			log.Fatalf("Unable to start. bifrost-gateway requires either PROXY_GATEWAY_URL or STRN_ORCHESTRATOR_URL to be set.\n\nRead docs at https://github.com/ipfs/bifrost-gateway/blob/main/docs/environment-variables.md\n\n")
 		}
 
-		ipnsProxyGateway := getEnvs(EnvIPNSRecordGateway, "")
-		gatewaySrv, err := makeGatewayHandler(bs, kuboRPC, ipnsProxyGateway, gatewayPort, blockCacheSize, cdns, useGraphBackend)
+		// Prefer IPNS_RECORD_GATEWAY_URL when an explicit URL for IPNS routing is set
+		ipnsRecordGateway := getEnvs(EnvIPNSRecordGateway, "")
+		if len(ipnsRecordGateway) == 0 {
+			// Fallback to PROXY_GATEWAY_URL, assuming it is modern
+			// enough to support application/vnd.ipfs.ipns-record responses
+			ipnsRecordGateway = proxyGateway
+		}
+
+		gatewaySrv, err := makeGatewayHandler(bs, kuboRPC, ipnsRecordGateway, gatewayPort, blockCacheSize, cdns, useGraphBackend)
 		if err != nil {
 			return err
 		}

routing.go

@@ -156,17 +156,17 @@ func (ps *rpcProxyRouting) getRandomKuboURL() string {
 }
 
 type proxyRouting struct {
-	gatewayURLs []string
-	httpClient  *http.Client
-	rand        *rand.Rand
+	ipnsRecordGateways []string
+	httpClient         *http.Client
+	rand               *rand.Rand
 }
 
-func newProxyRouting(gatewayURLs []string, cdns *cachedDNS) routing.ValueStore {
+func newProxyRouting(ipnsRecordGateways []string, cdns *cachedDNS) routing.ValueStore {
 	s := rand.NewSource(time.Now().Unix())
 	rand := rand.New(s)
 
 	return &proxyRouting{
-		gatewayURLs: gatewayURLs,
+		ipnsRecordGateways: ipnsRecordGateways,
 		httpClient: &http.Client{
 			Transport: otelhttp.NewTransport(&customTransport{
 				// RoundTripper with increased defaults than http.Transport such that retrieving
@@ -276,5 +276,5 @@ func (ps *proxyRouting) fetch(ctx context.Context, name ipns.Name) ([]byte, erro
 }
 
 func (ps *proxyRouting) getRandomGatewayURL() string {
-	return strings.TrimSuffix(ps.gatewayURLs[ps.rand.Intn(len(ps.gatewayURLs))], "/")
+	return strings.TrimSuffix(ps.ipnsRecordGateways[ps.rand.Intn(len(ps.ipnsRecordGateways))], "/")
 }