Make flag more optional-looking

internal/client/client.go

@@ -91,19 +91,9 @@ func DialOptsFromFlags(cmd *cobra.Command, token storage.Token) ([]grpc.DialOpti
 		interceptors = append(interceptors, zgrpcutil.CheckServerVersion)
 	}
 
-	maxMessageSize := cobrautil.MustGetInt(cmd, "max-message-size")
-
 	opts := []grpc.DialOption{
 		grpc.WithChainUnaryInterceptor(interceptors...),
 		grpc.WithChainStreamInterceptor(zgrpcutil.StreamLogDispatchTrailers),
-		grpc.WithDefaultCallOptions(
-			// The default max client message size is 4mb.
-			// It's conceivable that a sufficiently complex
-			// schema will easily surpass this, so we set the
-			// limit higher here.
-			grpc.MaxCallRecvMsgSize(maxMessageSize),
-			grpc.MaxCallSendMsgSize(maxMessageSize),
-		),
 	}
 
 	if cobrautil.MustGetBool(cmd, "insecure") || (token.IsInsecure()) {
@@ -123,5 +113,17 @@ func DialOptsFromFlags(cmd *cobra.Command, token storage.Token) ([]grpc.DialOpti
 		opts = append(opts, grpc.WithAuthority(hostnameOverride))
 	}
 
+	maxMessageSize := cobrautil.MustGetInt(cmd, "max-message-size")
+	if maxMessageSize != 0 {
+		opts = append(opts, grpc.WithDefaultCallOptions(
+			// The default max client message size is 4mb.
+			// It's conceivable that a sufficiently complex
+			// schema will easily surpass this, so we set the
+			// limit higher here.
+			grpc.MaxCallRecvMsgSize(maxMessageSize),
+			grpc.MaxCallSendMsgSize(maxMessageSize),
+		))
+	}
+
 	return opts, nil
 }

internal/cmd/cmd.go

@@ -75,7 +75,7 @@ func Run() {
 	rootCmd.PersistentFlags().Bool("no-verify-ca", false, "do not attempt to verify the server's certificate chain and host name")
 	rootCmd.PersistentFlags().Bool("debug", false, "enable debug logging")
 	rootCmd.PersistentFlags().String("request-id", "", "optional id to send along with SpiceDB requests for tracing")
-	rootCmd.PersistentFlags().Int("max-message-size", 4*1024*1024, "maximum size (bytes) of a gRPC message sent or received by zed")
+	rootCmd.PersistentFlags().Int("max-message-size", 0, "maximum size (bytes) of a gRPC message that can be sent or received by zed")
 	_ = rootCmd.PersistentFlags().MarkHidden("debug") // This cannot return its error.
 
 	versionCmd := &cobra.Command{