lack kubernetes support

[xial-thu]

I'm trying to run elastalert on kubernetes. When I see there's docker image, I immediately turn to this project and docker hub. But sadly, I have not seen guidance for kubernetes. I guess it's better to add some README to kubernetes users.

Though I'm familiar with k8s, I still met a problem. I attempted to mount rules to "/opt/elastalert/rules" but failed. The logs are

Duplicated rule ... on /opt/elastalert/rules/..2020.04.28.xxxxx/xxxx.yaml

I googled and found the reason: Yelp/elastalert#1832. Elastalert creates a symlink. So I'm expecting some clearer guidance to ease kubernetes users.

I'm willing to do the part if you agree with me, either in this repo or in Yelp/elastalert.