cli/command/container: don't mutate ConfigFile.DetachKeys

This code was introduced in moby/moby@15aa2a6,
but from those changes, it appears that overwriting the config value was
merely out of convenience, and that struct being used as an intermediate.

While changing the config here should be mostly ephemeral, and not written
back to the config-file, let's be clear on intent, and not mutatte the config
as part of this code.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

cli/command/container/attach.go

@@ -86,16 +86,17 @@ func runAttach(dockerCli command.Cli, opts *attachOptions) error {
 		return err
 	}
 
+	detachKeys := dockerCli.ConfigFile().DetachKeys
 	if opts.detachKeys != "" {
-		dockerCli.ConfigFile().DetachKeys = opts.detachKeys
+		detachKeys = opts.detachKeys
 	}
 
 	options := types.ContainerAttachOptions{
 		Stream:     true,
 		Stdin:      !opts.noStdin && c.Config.OpenStdin,
 		Stdout:     true,
 		Stderr:     true,
-		DetachKeys: dockerCli.ConfigFile().DetachKeys,
+		DetachKeys: detachKeys,
 	}
 
 	var in io.ReadCloser

cli/command/container/run.go

@@ -169,11 +169,18 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 	}
 	attach := config.AttachStdin || config.AttachStdout || config.AttachStderr
 	if attach {
+		detachKeys := dockerCli.ConfigFile().DetachKeys
 		if opts.detachKeys != "" {
-			dockerCli.ConfigFile().DetachKeys = opts.detachKeys
+			detachKeys = opts.detachKeys
 		}
 
-		closeFn, err := attachContainer(ctx, dockerCli, &errCh, config, containerID)
+		closeFn, err := attachContainer(ctx, dockerCli, containerID, &errCh, config, types.ContainerAttachOptions{
+			Stream:     true,
+			Stdin:      config.AttachStdin,
+			Stdout:     config.AttachStdout,
+			Stderr:     config.AttachStderr,
+			DetachKeys: detachKeys,
+		})
 		if err != nil {
 			return err
 		}
@@ -232,15 +239,7 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 	return nil
 }
 
-func attachContainer(ctx context.Context, dockerCli command.Cli, errCh *chan error, config *container.Config, containerID string) (func(), error) {
-	options := types.ContainerAttachOptions{
-		Stream:     true,
-		Stdin:      config.AttachStdin,
-		Stdout:     config.AttachStdout,
-		Stderr:     config.AttachStderr,
-		DetachKeys: dockerCli.ConfigFile().DetachKeys,
-	}
-
+func attachContainer(ctx context.Context, dockerCli command.Cli, containerID string, errCh *chan error, config *container.Config, options types.ContainerAttachOptions) (func(), error) {
 	resp, errAttach := dockerCli.Client().ContainerAttach(ctx, containerID, options)
 	if errAttach != nil {
 		return nil, errAttach
@@ -250,13 +249,13 @@ func attachContainer(ctx context.Context, dockerCli command.Cli, errCh *chan err
 		out, cerr io.Writer
 		in        io.ReadCloser
 	)
-	if config.AttachStdin {
+	if options.Stdin {
 		in = dockerCli.In()
 	}
-	if config.AttachStdout {
+	if options.Stdout {
 		out = dockerCli.Out()
 	}
-	if config.AttachStderr {
+	if options.Stderr {
 		if config.Tty {
 			cerr = dockerCli.Out()
 		} else {

cli/command/container/start.go

@@ -94,16 +94,17 @@ func RunStart(dockerCli command.Cli, opts *StartOptions) error {
 			defer signal.StopCatch(sigc)
 		}
 
+		detachKeys := dockerCli.ConfigFile().DetachKeys
 		if opts.DetachKeys != "" {
-			dockerCli.ConfigFile().DetachKeys = opts.DetachKeys
+			detachKeys = opts.DetachKeys
 		}
 
 		options := types.ContainerAttachOptions{
 			Stream:     true,
 			Stdin:      opts.OpenStdin && c.Config.OpenStdin,
 			Stdout:     true,
 			Stderr:     true,
-			DetachKeys: dockerCli.ConfigFile().DetachKeys,
+			DetachKeys: detachKeys,
 		}
 
 		var in io.ReadCloser