By default the helmchart deploy a postgresql database in your terrakube namespace but if you want to customize that you can change the default deployment values.
To use a PostgreSQL with your Terrakube deployment create a terrakube.yaml file with the following content:
loadSampleData this will add some organization, workspaces and modules by default in your database if need it
Now you can install terrakube using the command.
Postgresql SSL mode can be use adding databaseSslMode parameter by default the value is "disable", but it accepts the following values; disable, allow, prefer, require, verify-ca, verify-full. This feature is supported from Terrakube 2.15.0. Reference: https://jdbc.postgresql.org/documentation/publicapi/org/postgresql/PGProperty.html#SSL_MODE