The following HealthIndicators are auto-configured by Spring Boot when appropriate:

To provide custom health information you can register Spring beans that implement the HealthIndicator interface. You need to provide an implementation of the health() method and return a Health response. The Health response should include a status and can optionally include additional details to be displayed.

import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

@Component
public class MyHealth implements HealthIndicator {

    @Override
    public Health health() {
        int errorCode = check(); // perform some specific health check
        if (errorCode != 0) {
            return Health.down().withDetail("Error Code", errorCode).build();
        }
        return Health.up().build();
    }

}

In addition to Spring Boot’s predefined Status types, it is also possible for Health to return a custom Status that represents a new system state. In such cases a custom implementation of the HealthAggregator interface also needs to be provided, or the default implementation has to be configured using the management.health.status.order configuration property.

For example, assuming a new Status with code FATAL is being used in one of your HealthIndicator implementations. To configure the severity order add the following to your application properties:

management.health.status.order: DOWN, OUT_OF_SERVICE, UNKNOWN, UP

You might also want to register custom status mappings with the HealthMvcEndpoint if you access the health endpoint over HTTP. For example you could map FATAL to HttpStatus.SERVICE_UNAVAILABLE.

Rather than hardcoding some properties that are also specified in your project’s build configuration, you can automatically expand info properties using the existing build configuration instead. This is possible in both Maven and Gradle.

Automatic property expansion using Maven

You can automatically expand info properties from the Maven project using resource filtering. If you use the spring-boot-starter-parent you can then refer to your Maven ‘project properties’ via @..@ placeholders, e.g.

project.artifactId=myproject
project.name=Demo
project.version=X.X.X.X
project.description=Demo project for info endpoint
info.build.artifact[email protected]@
info.build.name[email protected]@
info.build.description[email protected]@
info.build.version[email protected]@

	Note
	In the above example we used project.* to set some values to be used as fallbacks if the Maven resource filtering has not been switched on for some reason.

	Tip
	The spring-boot:run maven goal adds src/main/resources directly to the classpath (for hot reloading purposes). This circumvents the resource filtering and this feature. You can use the exec:java goal instead or customize the plugin’s configuration, see the plugin usage page for more details.

If you don’t use the starter parent, in your pom.xml you need (inside the <build/> element):

<resources>
    <resource>
        <directory>src/main/resources</directory>
        <filtering>true</filtering>
    </resource>
</resources>

and (inside <plugins/>):

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <version>2.6</version>
    <configuration>
        <delimiters>
            <delimiter>@</delimiter>
        </delimiters>
    </configuration>
</plugin>

Automatic property expansion using Gradle

You can automatically expand info properties from the Gradle project by configuring the Java plugin’s processResources task to do so:

processResources {
    expand(project.properties)
}

You can then refer to your Gradle project’s properties via placeholders, e.g.

info.build.name=${name}
info.build.description=${description}
info.build.version=${version}

	Note
	Gradle’s expand method uses Groovy’s SimpleTemplateEngine which transforms ${..} tokens. The ${..} style conflicts with Spring’s own property placeholder mechanism. To use Spring property placeholders together with automatic expansion the Spring property placeholders need to be escaped like \${..}.

Another useful feature of the info endpoint is its ability to publish information about the state of your git source code repository when the project was built. If a git.properties file is contained in your jar the git.branch and git.commit properties will be loaded.

For Maven users the spring-boot-starter-parent POM includes a pre-configured plugin to generate a git.properties file. Simply add the following declaration to your POM:

<build>
    <plugins>
        <plugin>
            <groupId>pl.project13.maven</groupId>
            <artifactId>git-commit-id-plugin</artifactId>
        </plugin>
    </plugins>
</build>

A similar gradle-git plugin is also available for Gradle users, although a little more work is required to generate the properties file.