In this tutorial we are going to learn about Spring Boot Actuator and its configuration in the API Gateway.

Spring Boot Actuator

Spring Boot Actuator is a sub-project of the Spring Boot Framework. It includes a number of additional features that help us to monitor and manage the Spring Boot application. It contains the actuator endpoints (the place where the resources live). We can use HTTP and JMX endpoints to manage and monitor the Spring Boot application. If we want to get production-ready features in an application, we should use the Spring Boot actuator.

Spring Boot Actuator Features

There are three main features of Spring Boot Actuator:

• Endpoint: The actuator endpoints allows us to monitor and interact with the application. Spring Boot provides a number of built-in endpoints. We can also create our own endpoint. We can enable and disable each endpoint individually. Most of the application choose HTTP, where the Id of the endpoint, along with the prefix of /actuator, is mapped to a URL. For example, the /health endpoint provides the basic health information of an application. The actuator, by default, mapped it to /actuator/health.
• Metrics: Spring Boot Actuator provides dimensional metrics by integrating with the micrometer. The micrometer is integrated into Spring Boot. It is the instrumentation library powering the delivery of application metrics from Spring. It provides vendor-neutral interfaces for timers, gauges, counters, distribution summaries, and long task timers with a dimensional data model.
• Audit: Spring Boot provides a flexible audit framework that publishes events to an AuditEventRepository. It automatically publishes the authentication events if spring-security is in execution.

Configuration

We are going to configure Spring Boot Actuator in Spring Cloud API Gateway by adding the dependency mentioned below in the pom.xml.

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