should add docs how to create HA system with live backup/restore for the wordpress deployment

[hoatle]

This should work on local deployment and applicable for cloud deployment

[hoatle]

https://hackernoon.com/introducing-reshifter-for-kubernetes-backup-restore-migration-upgrade-ffaf78da36

[hoatle]

for backup/restore, we can use the following operators:

• https://github.com/heptio/ark
• https://github.com/appscode/stash

Let's see how it works by backing up https://github.com/teracyhq-incubator/teracy-dev-k8s/blob/develop/docs/ha-scalable-wordpress.md and restore everything to a new cluster with the expectation that the restored version should work the same as the backup one.

[hoatle]

https://github.com/weaveworks/flux could be great for resource sync (gitops)
https://github.com/heptio/ark + https://github.com/appscode/stash could be great for backup + restore of resources and persistent volumes.

[hoatle]

there is a problem when using stash with google cloud storage as a backend stashed/stash#520 (comment)

so we need to use restic directly for restoring instead of using stash recovery until restic is upgraded (I guess stash 0.9 will do)

[hoatle]

Heptico Ark is now Velero https://heptio.github.io/velero/v0.10.0/

[hoatle]

related issue: bitpoke/mysql-operator#234