config-location

config-location

Change the location that Spring Boot uses to find external configuration files.

Overview

See https://docs.spring.io/spring-boot/how-to/properties-and-configuration.html#howto.properties-and-configuration.external-properties-location

By default, properties from different sources are added to the Spring Environment in a defined order (see “Externalized Configuration” in the ‘Spring Boot features’ section for the exact order).

You can also provide the following System properties (or environment variables) to change the behavior:

• spring.config.name (SPRING_CONFIG_NAME): Defaults to application as the root of the file name.
• spring.config.location (SPRING_CONFIG_LOCATION): The file to load (such as a classpath resource or a URL). A separate Environment property source is set up for this document and it can be overridden by system properties, environment variables, or the command line.

Instructions

Follow these instructions to build and run the example program.

1. Pre-requisite: Java
   • I used Java 21
2. Build the program distribution:

   • ./gradlew installDist

3. Run the program:

   • ./build/install/config-location/bin/config-location

   • It should print something like the following (some boilerplate omitted).

   • **************************************************
     Hello from the 'application-default.yml' file in classpath resources
     Goodbye from the 'application-default.yml' file in classpath resources
     **************************************************
     

4. Alternatively, tell the application to use an alternative location to find the config data

   • ./build/install/config-location/bin/config-location --spring.config.additional-location=file:alternate-config/

   • Notice how the message has changed. We're not getting "Goodbye" from the classpath resources config file but instead a "See you later" from the config file in the alternate-config/ directory.

   • **************************************************
     Hello from the 'application-default.yml' file in classpath resources
     See you later, from the 'application-default.yml' file in the 'alternate-config/' directory
     **************************************************
     

Reference

• Spring Boot docs: Externalized Configuration