fileExistsBehavior
Information about how CodeDeploy handles files that already exist in a deployment target location but weren't part of the previous successful deployment.
The fileExistsBehavior
parameter takes any of the following values:
DISALLOW: The deployment fails. This is also the default behavior if no option is specified.
OVERWRITE: The version of the file from the application revision currently being deployed replaces the version already on the instance.
RETAIN: The version of the file already on the instance is kept and used as part of the new deployment.