Spring Boot Admin and Health Endpoints

Table of Contents

1. What is Spring Boot Admin?
2. Why Use Spring Boot Admin?
3. Setting Up Spring Boot Admin Server
4. Registering Clients to the Admin Server
5. Exploring Spring Boot Admin Dashboard
6. Spring Boot Actuator Health Endpoints
7. Custom Health Indicators
8. Securing Spring Boot Admin
9. Spring Boot Admin Notifications and Alerts
10. Summary

1. What is Spring Boot Admin?

Spring Boot Admin is a community-driven project by Codecentric that provides a web-based UI for managing and monitoring Spring Boot applications. It leverages Spring Boot Actuator under the hood to gather metrics and system health data, presenting it in a centralized, visual format. It’s especially useful when you have multiple microservices running and need a single pane of glass to monitor them all.

2. Why Use Spring Boot Admin?

• Monitor multiple Spring Boot applications in one dashboard
• Visual representation of application metrics, logs, environment, and endpoints
• Easily track application status and health
• Customize health checks and alerts
• Centralize management of log levels, threads, and JVM state

3. Setting Up Spring Boot Admin Server

To set up a Spring Boot Admin Server:

Add Dependencies

In your Admin Server’s pom.xml:

xmlCopyEdit<dependency>
    <groupId>de.codecentric</groupId>
    <artifactId>spring-boot-admin-starter-server</artifactId>
    <version>3.1.8</version> <!-- Use compatible version -->
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

Enable Admin Server

javaCopyEdit@SpringBootApplication
@EnableAdminServer
public class AdminServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(AdminServerApplication.class, args);
    }
}

Basic Config in application.properties

propertiesCopyEditserver.port=8080
spring.application.name=admin-server

4. Registering Clients to the Admin Server

On each Spring Boot application you want to monitor:

Add Client Dependencies

xmlCopyEdit<dependency>
    <groupId>de.codecentric</groupId>
    <artifactId>spring-boot-admin-starter-client</artifactId>
    <version>3.1.8</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

Configure Application Properties

propertiesCopyEditspring.application.name=my-app
management.endpoints.web.exposure.include=*
spring.boot.admin.client.url=http://localhost:8080

Ensure that the actuator endpoints are exposed and accessible.

5. Exploring Spring Boot Admin Dashboard

Once everything is configured:

• Visit http://localhost:8080 (Admin Server UI)
• You’ll see the registered clients with their:
  • Health
  • Metrics
  • Beans
  • Environment variables
  • JVM memory, threads, GC info
  • Loggers and configuration
  • Custom endpoints

Each client is continuously monitored and updated in real time.

6. Spring Boot Actuator Health Endpoints

Spring Boot Admin uses the actuator’s /health endpoint to determine if an application is up or down.

By default, the /actuator/health shows a simple “UP” or “DOWN”. You can show detailed health information by setting:

propertiesCopyEditmanagement.endpoint.health.show-details=always

Default Health Indicators

Spring Boot includes indicators for:

• Disk space
• Database
• Redis, MongoDB
• Ping
• Custom indicators

7. Custom Health Indicators

You can define your own logic for health reporting:

javaCopyEdit@Component
public class MyCustomHealthIndicator implements HealthIndicator {

    @Override
    public Health health() {
        // Your custom logic
        boolean isHealthy = checkService();
        if (isHealthy) {
            return Health.up().withDetail("customService", "Available").build();
        } else {
            return Health.down().withDetail("customService", "Unavailable").build();
        }
    }

    private boolean checkService() {
        // Simulate a service check
        return true;
    }
}

This will appear under the /actuator/health and in the Spring Boot Admin dashboard.

8. Securing Spring Boot Admin

You can secure the Admin UI and client registration using Spring Security:

Security Configuration (Server)

javaCopyEdit@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/assets/**", "/login").permitAll()
                .anyRequest().authenticated()
            .and()
                .formLogin().loginPage("/login").permitAll()
            .and()
                .logout().permitAll();
    }
}

You can also secure the actuator endpoints on each client.

9. Spring Boot Admin Notifications and Alerts

Spring Boot Admin supports notifications via:

• Email
• Slack
• PagerDuty
• HipChat
• OpsGenie
• Let’s you define thresholds and alerting rules

To enable Slack integration, add:

xmlCopyEdit<dependency>
    <groupId>de.codecentric</groupId>
    <artifactId>spring-boot-admin-server-notifier-slack</artifactId>
</dependency>

And configure:

propertiesCopyEditspring.boot.admin.notify.slack.enabled=true
spring.boot.admin.notify.slack.webhook-url=https://hooks.slack.com/services/...

10. Summary

Spring Boot Admin combined with Actuator provides a comprehensive, real-time dashboard for managing and monitoring Spring Boot applications. It scales well for microservices, enhances observability, and supports both out-of-the-box and custom metrics and health indicators. It also improves operational response time by enabling secure, centralized monitoring with real-time notifications.