roleArn, err := arn.Parse(arnStr)
	if err != nil {
		return arn.ARN{}, "", fmt.Errorf("RoleARN parse err: %v", err)
	}
	rolePolicy, ok := sys.rolesMap[roleArn]
	if !ok {
		return arn.ARN{}, "", fmt.Errorf("RoleARN %s is not defined.", arnStr)
	}
	return roleArn, rolePolicy, nil
}

// DeletePolicy - deletes a canned policy from backend. `notifyPeers` is true