create: load default buildkit config if none specified

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

util/confutil/config.go

@@ -2,6 +2,7 @@ package confutil
 
 import (
 	"os"
+	"path"
 	"path/filepath"
 
 	"github.com/docker/cli/cli/command"
@@ -24,6 +25,15 @@ func ConfigDir(dockerCli command.Cli) string {
 	return buildxConfig
 }
 
+// DefaultConfigFile returns the default BuildKit configuration file path
+func DefaultConfigFile(dockerCli command.Cli) (string, bool) {
+	f := path.Join(ConfigDir(dockerCli), "buildkitd.default.toml")
+	if _, err := os.Stat(f); err == nil {
+		return f, true
+	}
+	return "", false
+}
+
 // loadConfigTree loads BuildKit config toml tree
 func loadConfigTree(fp string) (*toml.Tree, error) {
 	f, err := os.Open(fp)