Merge pull request #804 from tonistiigi/http-hijack-session

docker: dial session directly with http hijack

driver/docker/driver.go

@@ -40,6 +40,8 @@ func (d *Driver) Rm(ctx context.Context, force bool, rmVolume bool) error {
 func (d *Driver) Client(ctx context.Context) (*client.Client, error) {
 	return client.New(ctx, "", client.WithContextDialer(func(context.Context, string) (net.Conn, error) {
 		return d.DockerAPI.DialHijack(ctx, "/grpc", "h2c", nil)
+	}), client.WithSessionDialer(func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error) {
+		return d.DockerAPI.DialHijack(ctx, "/session", proto, meta)
 	}))
 }