storing some application values in kubernetes etcd?

Question

I have application that have some user settings and it runs on kubernetes cluster. I would like the user settings to survive application crash/pod restart.

I was thinking first about having a DB instance for keeping it outside of kubernetes. Then I thought, maybe I could just abuse etcd to store small amount of custom data. Is it a good approach to keep things simple?

Another options I see:

1. separate db instance outside of kubernetes(overkill)
2. some json file on PV volume in kubernetes being constantly re-read.
3. perhaps use hashicorp vault?

What would you use? Its very small amount of data

Answer 1

If you want to use etcd, a Kubernetes built-in database, it's not really suited for this purpose and shouldn't be used in practice. App shouldn't know about Kubernetes. You need to use DB or PVC to store app related objects in a disk (for example json, yaml or other files).

Answer 2

you can use Persistent Volume and Persistent Volume claim. pvc or Persistent Volume claim will keep data incase of pod restart or pod crash. this the best way i think to store user data. you can have the suitable storage type and resource size as per your requirement. you can look into official doc. Ref