8.9. Secrets#

Presto manages configuration details in static properties files. This configuration needs to include values such as usernames, passwords and other strings, that are often required to be kept secret. Only a few select administrators or the provisioning system has access to the actual value.

The secrets support in Presto allows you to use environment variables as values for any configuration property. All properties files used by Presto, including config.properties and all catalog properties files are supported. When loading the properties, Presto simply replaces the reference to the environment variable with the value of the environment variable.

Environment variables are the most widely supported means of setting and retrieving values. Most provisioning and configuration management systems include support for setting environment variables. This includes systems such as Ansible, often used for virtual machines, and Kubernetes for container usage. Setting an environment variable can be done manually on the command line as well.

export DB_PASSWORD=my-super-secret-pwd

To use this variable in the properties file, you reference it with the syntax ${ENV:VARIABLE}. For example, if you want to use the password in a catalog properties file like etc/catalog/db.properties, add the following line:


With this setup in place the secret is only managed by the provisioning system or the administrators handling the machines. No secret is stored in the Presto configuration files on the filesystem and wherever they are managed.