Actuator Endpoints

Health checks, info, metrics and securing actuator in production.

Advanced10 min read

Read these first

Properties, YAML, and Profiles

Why this matters

Kubernetes liveness and readiness probes need a reliable endpoint that returns 200 only when the app can actually handle requests.
Custom health indicators let you surface BookStore-specific dependencies: database connectivity, Redis reachability, and payment gateway status.
Metrics endpoints feed Prometheus and Grafana dashboards — request rates, error ratios, and JVM memory without writing instrumentation from scratch.

Logs

Logback + MDCStructured JSON

Metrics

MicrometerCounters, timers

Traces

OpenTelemetryTrace propagation

Logs, metrics and traces — the three pillars wired through Actuator and Micrometer.

Actuator endpoints you will use daily

/actuator/health — aggregated health with component breakdown (db, redis, diskSpace).
/actuator/metrics — lists available Micrometer meters; append a name for current values.
/actuator/info — build metadata from info.* properties and custom InfoContributor beans.
/actuator/prometheus — scrape-friendly metrics export when the Prometheus registry is on the classpath.
HealthIndicator — implement this interface to add custom checks to the health aggregate.

Add Actuator and expose endpoints

Java

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-registry-prometheus</artifactId>
</dependency>

Java

management:
  endpoints:
    web:
      exposure:
        include: health,info,metrics,prometheus
  endpoint:
    health:
      show-details: when_authorized
      probes:
        enabled: true  # adds /actuator/health/liveness and /readiness
  info:
    env:
      enabled: true

info:
  app:
    name: BookStore API
    version: 2.4.1

Custom health for external dependencies

Java

@Component
public class PaymentGatewayHealthIndicator implements HealthIndicator {

    private final PaymentGatewayClient paymentClient;

    public PaymentGatewayHealthIndicator(PaymentGatewayClient paymentClient) {
        this.paymentClient = paymentClient;
    }

    @Override
    public Health health() {
        try {
            paymentClient.ping();
            return Health.up()
                    .withDetail("gateway", "stripe")
                    .withDetail("latencyMs", paymentClient.lastPingLatency())
                    .build();
        } catch (Exception ex) {
            return Health.down()
                    .withDetail("gateway", "stripe")
                    .withDetail("error", ex.getMessage())
                    .build();
        }
    }
}

Java

@Component
public class CatalogHealthContributor implements HealthContributor {

    private final BookRepository bookRepository;

    @Override
    public Health health() {
        long count = bookRepository.count();
        if (count == 0) {
            return Health.outOfService()
                    .withDetail("reason", "catalog empty — seed data missing")
                    .build();
        }
        return Health.up().withDetail("bookCount", count).build();
    }
}

Secure actuator in production

Java

@Configuration
public class ActuatorSecurityConfig {

    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SecurityFilterChain actuatorSecurity(HttpSecurity http) throws Exception {
        return http
                .securityMatcher("/actuator/**")
                .authorizeHttpRequests(auth -> auth
                        .requestMatchers("/actuator/health", "/actuator/health/**").permitAll()
                        .requestMatchers("/actuator/prometheus").hasRole("MONITORING")
                        .anyRequest().hasRole("ADMIN"))
                .httpBasic(Customizer.withDefaults())
                .build();
    }
}

Quick recall

Everything you need if you only revisit this box.

spring-boot-starter-actuator auto-configures health, metrics, and info endpoints.
Expose only what you need via management.endpoints.web.exposure.include.
Implement HealthIndicator for BookStore-specific dependency checks.
Use OUT_OF_SERVICE when the app is running but should not receive traffic (empty catalog, maintenance mode).
Lock down actuator endpoints in production; leave health probes public for orchestrators.

Test yourself

Answer these before moving on — recall is what makes it stick.