cli/command/registry: remove all uses of response message

[thaJeztah]

The message returned by the API is a hardcoded message; the only real information currently returned by the API is whether or not the auth was successul;
https://github.com/moby/moby/blob/v2.0.0-beta.0/daemon/server/router/system/system_routes.go#L408-L421

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 61.90476% with 8 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
cli/command/registry/login.go	61.90%	8 Missing ⚠️

📢 Thoughts on this report? Let us know!

[thaJeztah]

Flaky test, or did break something?

67.19 === Failed
67.19 === FAIL: cli/command/registry TestLoginWithCredStoreCreds (0.00s)
67.19     login_test.go:80: assertion failed: expected an error, got nil
67.19 
67.19 === FAIL: cli/command/registry TestRunLogin/expired_auth_from_store (0.00s)
67.19     login_test.go:309: assertion failed: expected an error, got nil
67.19 
67.19 === FAIL: cli/command/registry TestRunLogin (0.01s)

[thaJeztah]

Ah! The existing code shadowed the error; so this function would return when failing to store the credentials, but the error returned is the error from earlier?? return response.Status, err returns the err from response, err := dockerCLI.Client().RegistryLogin(ctx, authConfig), but even on failure, it would still try to store the credentials 🤔

I suspect that was a bug!

[thaJeztah]

I think this may have been introduced in 6e4818e

Before that patch, loginWithCredStoreCreds would only try to login, but did not handle saving credentials.

cli/cli/command/registry/login.go

Lines 145 to 157 in fcfdd7b

	func loginWithCredStoreCreds(ctx context.Context, dockerCli command.Cli, authConfig *registrytypes.AuthConfig) (registrytypes.AuthenticateOKBody, error) {
	fmt.Fprintf(dockerCli.Out(), "Authenticating with existing credentials...\n")
	cliClient := dockerCli.Client()
	response, err := cliClient.RegistryLogin(ctx, *authConfig)
	if err != nil {
	if errdefs.IsUnauthorized(err) {
	fmt.Fprintf(dockerCli.Err(), "Stored credentials invalid or expired\n")
	} else {
	fmt.Fprintf(dockerCli.Err(), "Login did not succeed, error: %s\n", err)
	}
	}
	return response, err
	}

So question is; was it intentional to save credentials even if they were invalid or expired? Or was the intent perhaps to remove / reset those credentials so that they wouldn't be used again?

cli/cli/command/registry/login.go

Lines 179 to 181 in be97096

	if err := storeCredentials(dockerCLI.ConfigFile(), authConfig); err != nil {
	return "", err
	}