Spring Boot Actuator Skill

Overview

Deliver production-ready observability for Spring Boot services using Actuator endpoints, probes, and Micrometer integration.
Standardize health, metrics, and diagnostics configuration while delegating deep reference material to
```
references/
```
.
Support platform requirements for secure operations, SLO reporting, and incident diagnostics.

When to Use

Trigger: "enable actuator endpoints" – Bootstrap Actuator for a new or existing Spring Boot service.
Trigger: "secure management port" – Apply Spring Security policies to protect management traffic.
Trigger: "configure health probes" – Define readiness and liveness groups for orchestrators.
Trigger: "export metrics to prometheus" – Wire Micrometer registries and tune metric exposure.
Trigger: "debug actuator startup" – Inspect condition evaluations and startup metrics when endpoints are missing or slow.

Quick Start

Add the starter dependency.

xml

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

gradle

// Gradle
dependencies {
    implementation "org.springframework.boot:spring-boot-starter-actuator"
}

Restart the service and verify
```
/actuator/health
```
and
```
/actuator/info
```
respond with
```
200 OK
```
.

Implementation Workflow

1. Expose the required endpoints

Set
```
management.endpoints.web.exposure.include
```
to the precise list or
```
"*"
```
for internal deployments.

Adjust

management.endpoints.web.base-path

(e.g.,

/management

) when the default

/actuator

conflicts with routing.

Review detailed endpoint semantics in
```
references/endpoint-reference.md
```
.

2. Secure management traffic

Apply an isolated

SecurityFilterChain

using

EndpointRequest.toAnyEndpoint()

with role-based rules.

Combine
```
management.server.port
```
with firewall controls or service mesh policies for operator-only access.
Keep
```
/actuator/health/**
```
publicly accessible only when required; otherwise enforce authentication.

3. Configure health probes

Enable

management.endpoint.health.probes.enabled=true

for

/health/liveness

and

/health/readiness

Group indicators via
```
management.endpoint.health.group.*
```
to match platform expectations.

Implement custom indicators by extending

HealthIndicator

ReactiveHealthContributor

; sample implementations live in

references/examples.md#custom-health-indicator

4. Publish metrics and traces

Activate Micrometer exporters (Prometheus, OTLP, Wavefront, StatsD) via
```
management.metrics.export.*
```
.
Apply
```
MeterRegistryCustomizer
```
beans to add
```
application
```
,
```
environment
```
, and business tags for observability correlation.
Surface HTTP request metrics with
```
server.observation.*
```
configuration when using Spring Boot 3.2+.

5. Enable diagnostics tooling

Turn on
```
/actuator/startup
```
(Spring Boot 3.5+) and
```
/actuator/conditions
```
during incident response to inspect auto-configuration decisions.

HttpExchangeRepository

(e.g.,

InMemoryHttpExchangeRepository

) before enabling

/actuator/httpexchanges

for request auditing.

Consult
```
references/official-actuator-docs.md
```
for endpoint behaviors and limits.

Examples

Basic – Expose health and info safely

yaml

management:
  endpoints:
    web:
      exposure:
        include: "health,info"
  endpoint:
    health:
      show-details: never

Intermediate – Readiness group with custom indicator

java

@Component
public class PaymentsGatewayHealth implements HealthIndicator {

    private final PaymentsClient client;

    public PaymentsGatewayHealth(PaymentsClient client) {
        this.client = client;
    }

    @Override
    public Health health() {
        boolean reachable = client.ping();
        return reachable ? Health.up().withDetail("latencyMs", client.latency()).build()
                         : Health.down().withDetail("error", "Gateway timeout").build();
    }
}

yaml

management:
  endpoint:
    health:
      probes:
        enabled: true
      group:
        readiness:
          include: "readinessState,db,paymentsGateway"
          show-details: always

Advanced – Dedicated management port with Prometheus export

yaml

management:
  server:
    port: 9091
    ssl:
      enabled: true
  endpoints:
    web:
      exposure:
        include: "health,info,metrics,prometheus"
      base-path: "/management"
  metrics:
    export:
      prometheus:
        descriptions: true
        step: 30s
  endpoint:
    health:
      show-details: when-authorized
      roles: "ENDPOINT_ADMIN"

java

@Configuration
public class ActuatorSecurityConfig {

    @Bean
    SecurityFilterChain actuatorChain(HttpSecurity http) throws Exception {
        http.securityMatcher(EndpointRequest.toAnyEndpoint())
            .authorizeHttpRequests(c -> c
                .requestMatchers(EndpointRequest.to("health")).permitAll()
                .anyRequest().hasRole("ENDPOINT_ADMIN"))
            .httpBasic(Customizer.withDefaults());
        return http.build();
    }
}

More end-to-end samples are available in

references/examples.md

Best Practices

Keep SKILL.md concise and rely on
```
references/
```
for verbose documentation to conserve context.
Apply the principle of least privilege: expose only required endpoints and restrict sensitive ones.
Use immutable configuration via profile-specific YAML to align environments.
Monitor actuator traffic separately to detect scraping abuse or brute-force attempts.
Automate regression checks by scripting
```
curl
```
probes in CI/CD pipelines.

Constraints

Avoid exposing

/actuator/env

/actuator/configprops

/actuator/logfile

, and

/actuator/heapdump

on public networks.

Do not ship custom health indicators that block event loop threads or exceed 250 ms unless absolutely necessary.
Ensure Actuator metrics exporters run on supported Micrometer registries; unsupported exporters require custom registry beans.
Maintain compatibility with Spring Boot 3.5.x conventions; older versions may lack probes and observation features.

Reference Materials

Endpoint quick reference
Implementation examples
Official documentation extract
Auditing with Actuator
Cloud Foundry integration
Enabling Actuator features
HTTP exchange recording
JMX exposure
Monitoring and metrics
Logging configuration
Metrics exporters
Observability with Micrometer
Process and Monitoring
Tracing
Scripts directory (
```
scripts/
```
) reserved for future automation; no runtime dependencies today.

Validation Checklist

Confirm
```
mvn spring-boot:run
```
or
```
./gradlew bootRun
```
exposes expected endpoints under
```
/actuator
```
(or custom base path).
Verify
```
/actuator/health/readiness
```
returns
```
UP
```
with all mandatory components before promoting to production.

Scrape

/actuator/metrics

/actuator/prometheus

to ensure required meters (

http.server.requests

jvm.memory.used

) are present.

Run security scans to validate only intended ports and endpoints are reachable from outside the trusted network.

spring-boot-actuator

NPX Install

Tags

SKILL.md Content

Spring Boot Actuator Skill

Overview

When to Use

Quick Start

Implementation Workflow

1. Expose the required endpoints

2. Secure management traffic

3. Configure health probes

4. Publish metrics and traces

5. Enable diagnostics tooling

Examples

Basic – Expose health and info safely

Intermediate – Readiness group with custom indicator

Advanced – Dedicated management port with Prometheus export

Best Practices

Constraints

Reference Materials

Validation Checklist