Which of the following policies would permit a user to generate dynamic credentials on a...

Comprehensive and Detailed in Depth Explanation:

The Database secrets engine generates dynamic credentials for database access. The endpoint database/creds/ < role > (e.g., read_only_role) provides these credentials via a read operation. Let’s analyze:

Option A: capabilities = [ " generate " ] There’s no generate capability in Vault policies. Capabilities are create, read, update, delete, list, etc. This is invalid. Incorrect.

Option B: capabilities = [ " update " ] update (PUT) modifies existing data, not generates credentials. The creds endpoint uses GET. Incorrect.

Option C: capabilities = [ " list " ] list retrieves metadata or paths, not credential data. Incorrect.

Option D: capabilities = [ " read " ] Generating dynamic credentials involves a GET request to database/creds/ < role > , mapped to the read capability. This policy allows it. Correct.

Detailed Mechanics:

For a role read_only_role defined with vault write database/roles/read_only_role db_name=my-db creation_statements= " CREATE USER... " , a user with read on database/creds/read_only_role can run vault read database/creds/read_only_role to get temporary credentials. Vault’s policy system aligns HTTP verbs to capabilities: GET = read, PUT = update. This counterintuitive mapping (GET for creation) is specific to dynamic secrets.

Overall Explanation from Vault Docs:

“Generating database credentials requires read capability on database/creds/ < role > … Despite creating credentials, the HTTP request is a GET.”