Revert "cmd/docker: split handling exit-code to a separate utility"

This reverts commit 4c62b2a.

cmd/docker/docker.go

@@ -29,41 +29,43 @@ import (
 )
 
 func main() {
-	err := dockerMain(context.Background())
-	if err != nil && !errdefs.IsCancelled(err) {
-		_, _ = fmt.Fprintln(os.Stderr, err)
-		os.Exit(getExitCode(err))
+	statusCode := dockerMain()
+	if statusCode != 0 {
+		os.Exit(statusCode)
 	}
 }
 
-func dockerMain(ctx context.Context) error {
-	ctx, cancelNotify := signal.NotifyContext(ctx, platformsignals.TerminationSignals...)
+func dockerMain() int {
+	ctx, cancelNotify := signal.NotifyContext(context.Background(), platformsignals.TerminationSignals...)
 	defer cancelNotify()
 
 	dockerCli, err := command.NewDockerCli(command.WithBaseContext(ctx))
 	if err != nil {
-		return err
+		fmt.Fprintln(os.Stderr, err)
+		return 1
 	}
 	logrus.SetOutput(dockerCli.Err())
 	otel.SetErrorHandler(debug.OTELErrorHandler)
 
-	return runDocker(ctx, dockerCli)
-}
-
-// getExitCode returns the exit-code to use for the given error.
-// If err is a [cli.StatusError] and has a StatusCode set, it uses the
-// status-code from it, otherwise it returns "1" for any error.
-func getExitCode(err error) int {
-	if err == nil {
-		return 0
-	}
-	var stErr cli.StatusError
-	if errors.As(err, &stErr) && stErr.StatusCode != 0 {
-		return stErr.StatusCode
+	if err := runDocker(ctx, dockerCli); err != nil {
+		if sterr, ok := err.(cli.StatusError); ok {
+			if sterr.Status != "" {
+				fmt.Fprintln(dockerCli.Err(), sterr.Status)
+			}
+			// StatusError should only be used for errors, and all errors should
+			// have a non-zero exit status, so never exit with 0
+			if sterr.StatusCode == 0 {
+				return 1
+			}
+			return sterr.StatusCode
+		}
+		if errdefs.IsCancelled(err) {
+			return 0
+		}
+		fmt.Fprintln(dockerCli.Err(), err)
+		return 1
 	}
-
-	// No status-code provided; all errors should have a non-zero exit code.
-	return 1
+	return 0
 }
 
 func newDockerCommand(dockerCli *command.DockerCli) *cli.TopLevelCommand {