cmd/gomote: use ListDirectoryStreaming

Use the streaming directory listing RPC to avoid
overflowing the maximum RPC response size.

For golang/go#69732

Change-Id: I2529d3788843844e3ccdde79c12c5c453b09bb25
Reviewed-on: https://go-review.googlesource.com/c/build/+/617161
Reviewed-by: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/gomote/ls.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"strings"
@@ -71,7 +72,7 @@ func ls(args []string) error {
 	}
 	for _, inst := range lsSet {
 		client := gomoteServerClient(ctx)
-		resp, err := client.ListDirectory(ctx, &protos.ListDirectoryRequest{
+		stream, err := client.ListDirectoryStreaming(ctx, &protos.ListDirectoryRequest{
 			GomoteId:  inst,
 			Directory: dir,
 			Recursive: recursive,
@@ -84,8 +85,17 @@ func ls(args []string) error {
 		if len(lsSet) > 1 {
 			fmt.Fprintf(os.Stdout, "# %s\n", inst)
 		}
-		for _, entry := range resp.GetEntries() {
-			fmt.Fprintf(os.Stdout, "%s\n", entry)
+		for {
+			resp, err := stream.Recv()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return fmt.Errorf("unable to ls: %w", err)
+			}
+			for _, entry := range resp.GetEntries() {
+				fmt.Fprintf(os.Stdout, "%s\n", entry)
+			}
 		}
 		if len(lsSet) > 1 {
 			fmt.Fprintln(os.Stdout)

cmd/gomote/push.go

@@ -76,7 +76,7 @@ func doPush(ctx context.Context, name, goroot string, dryRun, detailedProgress b
 	remote := map[string]buildlet.DirEntry{} // keys like "src/make.bash"
 
 	client := gomoteServerClient(ctx)
-	resp, err := client.ListDirectory(ctx, &protos.ListDirectoryRequest{
+	stream, err := client.ListDirectoryStreaming(ctx, &protos.ListDirectoryRequest{
 		GomoteId:  name,
 		Directory: ".",
 		Recursive: true,
@@ -99,11 +99,20 @@ func doPush(ctx context.Context, name, goroot string, dryRun, detailedProgress b
 	if err != nil {
 		return fmt.Errorf("error listing buildlet's existing files: %w", err)
 	}
-	for _, entry := range resp.GetEntries() {
-		de := buildlet.DirEntry{Line: entry}
-		en := de.Name()
-		if strings.HasPrefix(en, "go/") && en != "go/" {
-			remote[en[len("go/"):]] = de
+	for {
+		resp, err := stream.Recv()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return fmt.Errorf("error listing buildlet's existing files: %w", err)
+		}
+		for _, entry := range resp.GetEntries() {
+			de := buildlet.DirEntry{Line: entry}
+			en := de.Name()
+			if strings.HasPrefix(en, "go/") && en != "go/" {
+				remote[en[len("go/"):]] = de
+			}
 		}
 	}
 	// TODO(66635) remove once gomotes can no longer be created via the coordinator.