Spring Boot Actuator: Monitoring and Managing Your App

Spring Boot Actuator is a powerful set of production-ready features that provides valuable insights into the internals of your Spring Boot application. It offers various endpoints for monitoring, managing, and interacting with your application, making it an indispensable tool for maintaining and troubleshooting applications in production environments. In this article, we’ll explore the capabilities of Spring Boot Actuator and discuss how it can be leveraged to ensure the health and reliability of your Spring Boot applications.

Enabling Spring Boot Actuator

Integrating Spring Boot Actuator into your project is a straightforward process. You can enable it by adding the following dependency to your pom.xml or build.gradle file:

Maven:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

Gradle:

implementation 'org.springframework.boot:spring-boot-starter-actuator'

Once the dependency is added, Spring Boot Actuator is automatically configured with sensible defaults, and various endpoints become available for use.

Essential Actuator Endpoints

1. Health Endpoint:

The /actuator/health endpoint provides information about the health of your application. It performs various checks, such as database connectivity, disk space, and custom health indicators.

curl http://localhost:8080/actuator/health

2. Info Endpoint:

The /actuator/info endpoint displays arbitrary application information. You can customize this information by providing a info property in your application.properties or application.yml file.

curl http://localhost:8080/actuator/info

3. Metrics Endpoint:

The /actuator/metrics endpoint provides a wealth of information about your application’s metrics, including JVM statistics, garbage collection, and custom metrics.

curl http://localhost:8080/actuator/metrics

4. Env Endpoint:

The /actuator/env endpoint exposes information about the application’s environment, including properties, system properties, and configuration properties.

curl http://localhost:8080/actuator/env

Customizing Actuator Endpoints

While Spring Boot Actuator provides a set of default endpoints, you can customize which ones are enabled or disabled and configure additional properties to suit your application’s requirements. This can be achieved by modifying the application.properties or application.yml file.

# Enable all endpoints
management.endpoints.web.exposure.include=*

# Customize health check details
management.endpoint.health.show-details=always
management.health.db.enabled=true

Securing Actuator Endpoints

By default, all Actuator endpoints are secured, requiring proper authentication. You can customize the security settings in your application.properties or application.yml file.

# Enable security for all endpoints
management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always

# Configure security user roles
management.endpoint.health.roles=admin
management.endpoint.metrics.roles=admin
management.endpoint.env.roles=admin

Extending Actuator with Custom Endpoints

Spring Boot Actuator allows you to create custom endpoints to expose application-specific information. To create a custom endpoint, you can implement the Endpoint interface or extend the AbstractEndpoint class.

@Component
public class CustomEndpoint extends AbstractEndpoint<String> {

    public CustomEndpoint() {
        super("custom");
    }

    @Override
    public String invoke() {
        return "Custom endpoint invoked!";
    }
}

Your custom endpoint is then accessible at /actuator/custom.

Conclusion

Spring Boot Actuator simplifies the process of monitoring and managing your Spring Boot applications in production. By providing essential endpoints for health checks, metrics, and environment details, Actuator offers valuable insights into the runtime behavior of your application. With the ability to customize, secure, and extend these endpoints, Actuator becomes a versatile tool for maintaining the health and reliability of your Spring Boot applications. Integrate it into your projects to ensure a smooth and trouble-free operation in production environments.