In Juju, a configuration is a rule or a set of rules that define the behavior of your controller, model, or application.


Controller configuration

Controller configuration affects the operation of the controller as a whole.

See more: List of controller configuration keys, How to configure a controller

Model configuration

Model configuration affects behavior of a model, including the controller model.

See more: List of model configuration keys, How to configure a model

Application configuration

Application configuration affects the behavior of an application.

Application configuration keys are generally application-specific. Depending on what the charm author has decided, they can be used to allow the charm user to make certain decisions about the application, for example, the server port on which the application should be available, the resource profile, the DNS name, etc.

See examples: Charmhub | mysql > Configurations, Charmhub | traefik-k8s > Configurations, etc.

See more: How to configure an application

However, there is also a generic key, trust, that can be changed via juju trust.

See more: How to trust an application with a credential