how does that actually work? Vault has the user/password, and then acts as a gateway to the db?

IIRC, Vault has plugins with GRANT access to your database, and rotates your passwords automatically. So it is able to create new users when access is requested, and to rotate passwords if needed.

https://www.vaultproject.io/docs/secrets/databases/mysql-mar...

It looks like this https://www.nomadproject.io/docs/integrations/vault-integrat...

It's incredibly simple, and a breeze to use.

``` job "vault" { group "demo" { task "task" { vault { policies = ["database"] } template { env = true data = <<EOF {{ with secret "database/creds/production" }} DB_USERNAME={{.Data.username}} DB_PASSWORD={{.Data.password}} {{ end }} EOF } } } } ```

edit: thanks HN formatting

with this setup, Vault will create a new database user based on the configuration you set (read-only for some services, for example), and will attach a time-to-live to those credentials; as long as the application is using them, it will renew the TTL. When an application is killed, or scaling happens, etc, and the application instance isn't using those specific credentials, Vault will clean up and remove the unused account cleanly

Can do all sorts of great things with this; for example TLS (ssl) certificate renewals, etc, as the certificate expiry IS the TTL; when a certificate needs to be renewed it can happen automatically and your application can receive any signal you choose (SIGHUP, for example)

Fascinating! Thanks for sharing, I had no idea this was possible.