From 9ceda78057ba1341c98d532605465d71dd2e8916 Mon Sep 17 00:00:00 2001
From: Tonis Tiigi <tonistiigi@gmail.com>
Date: Wed, 5 Jun 2024 22:04:59 -0700
Subject: [PATCH] remote: ensure that client connection is not established
 twice

Because remote driver implements Info() by calling
Client() internally, two instances on Client are created
backed by separate TCP connection. This hack avoids it
and improves performance.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
---
 driver/remote/driver.go | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/driver/remote/driver.go b/driver/remote/driver.go
index 56b1078d..eaf47e85 100644
--- a/driver/remote/driver.go
+++ b/driver/remote/driver.go
@@ -7,6 +7,7 @@ import (
 	"net"
 	"os"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/docker/buildx/driver"
@@ -14,6 +15,7 @@ import (
 	"github.com/docker/buildx/util/progress"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/client/connhelper"
+	"github.com/moby/buildkit/util/tracing/delegated"
 	"github.com/pkg/errors"
 )
 
@@ -25,6 +27,11 @@ type Driver struct {
 	// https://github.com/docker/docs/blob/main/content/build/drivers/remote.md
 	*tlsOpts
 	defaultLoad bool
+
+	// remote driver caches the client because its Bootstap/Info methods reuse it internally
+	clientOnce sync.Once
+	client     *client.Client
+	err        error
 }
 
 type tlsOpts struct {
@@ -78,12 +85,18 @@ func (d *Driver) Rm(ctx context.Context, force, rmVolume, rmDaemon bool) error {
 }
 
 func (d *Driver) Client(ctx context.Context, opts ...client.ClientOpt) (*client.Client, error) {
-	opts = append([]client.ClientOpt{
-		client.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
-			return d.Dial(ctx)
-		}),
-	}, opts...)
-	return client.New(ctx, "", opts...)
+	d.clientOnce.Do(func() {
+		opts = append([]client.ClientOpt{
+			client.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
+				return d.Dial(ctx)
+			}),
+			client.WithTracerDelegate(delegated.DefaultExporter),
+		}, opts...)
+		c, err := client.New(ctx, "", opts...)
+		d.client = c
+		d.err = err
+	})
+	return d.client, d.err
 }
 
 func (d *Driver) Dial(ctx context.Context) (net.Conn, error) {