Update datastore read-only db user password on every run

[adborden]

User Story

In order to easily rotate credentials, data.gov team wants Inventory to automatically update the datastore read-only db user's password on startup.

Acceptance Criteria

[ACs should be clearly demoable/verifiable whenever possible. Try specifying them using BDD.]

• GIVEN I update DS_RO_PASSWORD in the user-provided service for inventory
  AND the application deploys successfully
  WHEN I cf connect-service to the datastore database
  THEN I can connect with the new DS_RO_PASSWORD

Background

[Any helpful contextual notes or links to artifacts/evidence, if needed]

Security Considerations (required)

[Any security concerns that might be implicated in the change. "None" is OK, just be explicit here!]

Sketch

[Notes or a checklist reflecting our understanding of the selected approach]