Spring Boot – spring.config.name – Case Study
Externalizing Spring Boot application properties is useful when the same application code must be used with different configuration. If the configuration is to be kept away from the source code (which is considered a best practice anyways)spring.config.location
environment property can be used to point the directory location with properties files for example. On the other hand, spring.config.name
can be used to change the base name of the properties file which defaults to application
. The documentation reads: if you don’t like application.properties as the configuration file name you can switch to another. But in what scenario spring.config.name
could be used.
(Potential) problem
One of the ways of providing spring.config.location
is by using environment variable: SPRING_CONFIG_LOCATION
. This can be considered useful when deploying Spring Boot application to Tomcat server. And when Spring Boot application starts it picks up application.properties
(with profile specific properties files) from SPRING_CONFIG_LOCATION
directory.
But what would happen when multiple Spring Boot applications are to be deployed to the same Tomcat server?
In such case we may expect some unexpected behavior as other applications will also pick app the application.properties
from SPRING_CONFIG_LOCATION
directory – and in case these are different app we may run into troubles.
(Potential) solution
One of the ways to solve the issue is to change the configuration base name in each application.
It can be done programatically in servlet initializer with spring.config.name
property:
import org.springframework.boot.builder.SpringApplicationBuilder; import org.springframework.boot.web.support.SpringBootServletInitializer; public class ServletInitializer extends SpringBootServletInitializer { @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { return application .properties("spring.config.name:my-app-1") .sources(MyApiApplication.class); } }
When starting the application, Spring Boot will expect that my-app-1.properties
exists (with profile specific variants e.g. my-app-1-test.properties
) . This way we may multiple applications deployed easily to the same Tomcat server with externalized configuration:
/data/config/my-app-1.properties /data/config/my-app-1-test.properties /data/config/my-app-2.properties /data/config/my-app-2-test.properties
Final thoughts
Hardcoding configuration is not the best solution, but in some scenarios there may be no better way than doing so.
Published on Java Code Geeks with permission by Rafal Borowiec, partner at our JCG program. See the original article here: Spring Boot – spring.config.name – Case Study Opinions expressed by Java Code Geeks contributors are their own. |
Is there any other way to give property file name other than in Servlet initializer
we can provide the below command to achieve:
java -jar boot-annotations-example-0.0.1-SNAPSHOT.jar –spring.config.name=qa-application
where, boot-annotations-example-0.0.1-SNAPSHOT is the name of jar,
qa-application is the name of your application.properties file.