Merge pull request #2501 from tonistiigi/remote-client-cache

remote: ensure that client connection is not established twice

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{
+	d.clientOnce.Do(func() {
-		client.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
+		opts = append([]client.ClientOpt{
-			return d.Dial(ctx)
+			client.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
-		}),
+				return d.Dial(ctx)
-	}, opts...)
+			}),
-	return client.New(ctx, "", opts...)
+			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) {