2. Overview

Kubernetes stores all its objects in etcd so backing up data in etcd is crucial for DR purposes. This project implements a tool that backs up etcd data and certificates to any S3 bucket. It follows the operator pattern that is popular in Kubernetes world.

An operator is basically a combination of custom resources (CRs) coupled with controllers that manage the CRs. There would be one controller for each CR. In addition to controllers, operators can also contain webhooks that can be used to validate the data in resources as well as to set defaults when some fields are not set in the resource specs. Our operator uses webhooks for both these purposes.

For data transfer to S3, we currently use a tool called restic. In the future, it will be possible to change the specific backup tool in a backwards compatible manner.

2.1. High level features of KubeDR

• Backup of etcd data and certificates to S3.

• Backups are encrypted and deduplicated.

• Can pause and resume backups.

• Can configure “retention” that controls how many backups are kept.

2.2. Requirements

• Since direct access to etcd is needed, Kubedr currently works only for clusters where etcd is accessible and a snapshot can be taken.

  This includes on-prem clusters as well as those in the cloud that are explicitly set up on the compute instances.

• Supported Versions: 1.13 - 1.17.