What is the difference between putting a property on application.yml or bootstrap.yml in spring boot?

Question

What is the difference between putting a property on application.yml or bootstrap.yml in spring boot? In logging.config case, the application works different.

Answer 1

I have just asked the Spring Cloud guys and thought I should share the info I have here.

bootstrap.yml is loaded before application.yml.

It is typically used for the following:

• when using Spring Cloud Config Server, you should specify spring.application.name and spring.cloud.config.server.git.uri inside bootstrap.yml
• some encryption/decryption information

Technically, bootstrap.yml is loaded by a parent Spring ApplicationContext. That parent ApplicationContext is loaded before the one that uses application.yml.

Answer 2

bootstrap.yml or bootstrap.properties

It's only used/needed if you're using Spring Cloud and your application's configuration is stored on a remote configuration server (e.g. Spring Cloud Config Server).

From the documentation:

A Spring Cloud application operates by creating a "bootstrap" context, which is a parent context for the main application. Out of the box it is responsible for loading configuration properties from the external sources, and also decrypting properties in the local external configuration files.

Note that the bootstrap.yml or bootstrap.properties can contain additional configuration (e.g. defaults) but generally you only need to put bootstrap config here.

Typically it contains two properties:

• location of the configuration server (spring.cloud.config.uri)
• name of the application (spring.application.name)

Upon startup, Spring Cloud makes an HTTP call to the config server with the name of the application and retrieves back that application's configuration.

application.yml or application.properties

Contains standard application configuration - typically default configuration since any configuration retrieved during the bootstrap process will override configuration defined here.