<p>I need to run a scheduled cron task in kubernetes to take mongodb back up and upload it to S3 bucket. 
Looking for a way to do it just via yaml file.</p>

ThatMan
<p>I would suggest you to use <a href="https://github.com/stefanprodan/mgob#configure" rel="nofollow noreferrer">mgob</a> which provide a yaml file for backup and upload it to S3 Object Storage.Moreover, it bring monitoring as well as notification feature. It can also be deployed on k8s.</p>

<p>A step by step guide on running MGOB as a StatefulSet with PersistentVolumeClaims can be found <a href="https://github.com/stefanprodan/mgob/tree/master/k8s" rel="nofollow noreferrer">here </a></p>
