allow client to be fully configurable via ENV variables

[seuros]

This change mirror how PG support PGUSER, PGPASSWORD .

reference: https://www.postgresql.org/docs/current/libpq-envars.html

[ankane]

Hi @seuros, thanks for the PR. These can all be set with the current environment variable (IMMUDB_URL), so I don't think others are needed.

[seuros]

@ankane I know about the IMMUDB_URL, but in my setup, i set just the user and password in the vault.

This is valid for both mysql and PG, and currently i'm trying to build an ActiveRecord adapter that has similar pattern using this gem.

[ankane]

You can include the logic in application code or the Active Record adapter if needed, but it's not something I'd like to include in this gem.

[seuros]

Fair enough.