Securing and Customizing Actuator Endpoints in Spring Boot

Actuator endpoints in Spring Boot provide various useful insights into the application's health, configuration, and performance. However, by default, these endpoints are accessible to anyone who has access to the application. In a production environment, it is crucial to secure these endpoints to prevent unauthorized access. Additionally, Actuator endpoints can be customized to meet specific requirements and provide more tailored information to the application administrators.

Securing Actuator Endpoints

Securing Actuator endpoints can be achieved by leveraging Spring Security, which provides a comprehensive security framework for Spring applications. The following steps outline how to secure Actuator endpoints in your Spring Boot application:

1. Add the Spring Security dependency to your project by adding the following dependency to your pom.xml or build.gradle file:

<!-- Maven -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

2. By default, Spring Security will protect all endpoints, including Actuator endpoints, by requiring authentication. However, Actuator endpoints should be accessible to authorized users only. To allow unauthenticated access to Actuator endpoints, modify the application.properties or application.yml file and add the following configuration:

# YAML
management:
  endpoints:
    web:
      exposure:
        include: "*"
  endpoint:
    health:
      show-details: when_authorized

The above configuration allows all Actuator endpoints to be accessible. You can further customize the list of exposed endpoints according to your requirements.

3. Configure user roles and access permissions by creating a SecurityConfig class that extends WebSecurityConfigurerAdapter and override the configure(HttpSecurity http) method:

// Java
@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .anyRequest().authenticated()
                .and()
            .formLogin().and()
            .httpBasic();
    }

}

The above configuration allows any authenticated user to access Actuator endpoints.

4. With the above configuration, you will be prompted to enter a username and password when accessing Actuator endpoints. To define the username and password, modify the application.properties or application.yml file and add the following configuration:

# YAML
spring:
  security:
    user:
      name: admin
      password: password
      roles: ACTUATOR_ADMIN

The above configuration sets the username to "admin" and the password to "password". It also assigns the "ACTUATOR_ADMIN" role to the user.

Customizing Actuator Endpoints

Actuator endpoints provide various insights into your application, and you can customize them to obtain more specific information or provide tailored information. Here are some ways to customize Actuator endpoints:

1. Include additional information in the /info endpoint by creating a class that implements the InfoContributor interface and override the contribute(Info.Builder builder) method:

// Java
@Component
public class CustomInfoContributor implements InfoContributor {

    @Override
    public void contribute(Info.Builder builder) {
        builder.withDetail("customKey", "customValue");
    }
}

The above code adds a custom key-value pair to the /info endpoint, providing additional information about your application.

2. Customize the /health endpoint by creating a class that extends HealthIndicator and override the health() method:

// Java
@Component
public class CustomHealthIndicator implements HealthIndicator {

    @Override
    public Health health() {
        // custom health check logic here
        return Health.up().build();
    }
}

You can add custom health checks in the health() method to determine the overall health of your application. The result of this check will be visible in the /health endpoint.

3. Exclude certain Actuator endpoints from being exposed by modifying the application.properties or application.yml file and add the following configuration:

# YAML
management:
  endpoints:
    web:
      exposure:
        exclude: env,beans

The above configuration excludes the /env and /beans endpoints from being accessible. You can customize the excluded endpoints according to your requirements.

By securing and customizing Actuator endpoints, you can ensure that your application's sensitive information is protected and present tailored insights to the application administrators. Spring Boot's Actuator provides a robust framework to monitor and manage your applications effectively.