KMS: Deployment and backup strategy

[kartpop]

Is your feature request related to a problem?
KMS is tested on staging but needs to be deployed to production. There is a risk of issues arising during deployment which could affect the recovery of encrypted credentials.

Describe the solution you'd like

• Backup the credentials table and test recovery of encrypted credentials
• Perform a database backup just before deployment
• Create an operations checklist for environment variables in the task definition

Original issue

Context

KMS work tested on staging, deploy to prod remains.

Next steps

• Credentials table backup; also test if we can recover encrypted credentials and recreate the table if deployment fails
• DB backup just before deploy
• Create ops checklist (any env vars to be taken care of in task definition?)