Spring Boot Admin – Admin UI for administration of spring boot applications

               As part of microservices development, many of us are using Spring Boot along with Spring Cloud features. In the microservices world, we will have many Spring Boot applications which will be running on same/different hosts. If we add Spring Actuator to the Spring Boot applications, we will get a lot of out of the box endpoints to monitor and interact with Spring Boot applications. The list is given below.

ID Description Sensitive Default
actuator Provides a hypermedia-based “discovery page” for the other endpoints. Requires Spring HATEOAS to be on the classpath. true
auditevents Exposes audit events information for the current application. true
autoconfig Displays an auto-configuration report showing all auto-configuration candidates and the reason why they ‘were’ or ‘were not’ applied. true
beans Displays a complete list of all the Spring beans in your application. true
configprops Displays a collated list of all @ConfigurationProperties. true
dump Performs a thread dump. true
env Exposes properties from Spring’s ConfigurableEnvironment. true
flyway Shows any Flyway database migrations that have been applied. true
health Shows application health information (when the application is secure, a simple ‘status’ when accessed over an unauthenticated connection or full message details when authenticated). false
info Displays arbitrary application info. false
loggers Shows and modifies the configuration of loggers in the application. true
liquibase Shows any Liquibase database migrations that have been applied. true
metrics Shows ‘metrics’ information for the current application. true
mappings Displays a collated list of all @RequestMapping paths. true
shutdown Allows the application to be gracefully shutdown (not enabled by default). true
trace Displays trace information (by default the last 100 HTTP requests). true

The above endpoints provide a lot of insights about Spring Boot application. But If you have many applications running then monitoring each application by hitting the endpoints and inspecting the JSON response is a tedious process. To avoid this hassle Code Centric team came up with Spring Boot Admin module which will provide us Admin UI Dashboard to administer  Spring Boot applications. This module crunches the data from Actuator endpoints and provides insights about all the registered applications in a single dashboard. Now we will demonstrate the Spring Boot Admin features in the following sections.

As a first step, create a Spring Boot application which we will make as Spring Boot Admin server module by adding the below maven dependencies.

<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-server</artifactId>
<version>1.5.1</version>
</dependency>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-server-ui</artifactId>
<version>1.5.1</version>
</dependency>

Add Spring Boot Admin Server configuration via adding @EnableAdminServer to your configuration.

package org.samrttechie;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import de.codecentric.boot.admin.config.EnableAdminServer;
@EnableAdminServer
@Configuration
@SpringBootApplication
public class SpringBootAdminApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootAdminApplication.class, args);
}
@Configuration
public static class SecurityConfig extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
// Page with login form is served as /login.html and does a POST on /login
http.formLogin().loginPage("/login.html").loginProcessingUrl("/login").permitAll();
// The UI does a POST on /logout on logout
http.logout().logoutUrl("/logout");
// The ui currently doesn't support csrf
http.csrf().disable();
// Requests for the login page and the static assets are allowed
http.authorizeRequests()
.antMatchers("/login.html", "/**/*.css", "/img/**", "/third-party/**")
.permitAll();
// … and any other request needs to be authorized
http.authorizeRequests().antMatchers("/**").authenticated();
// Enable so that the clients can authenticate via HTTP basic for registering
http.httpBasic();
}
}
// end::configuration-spring-security[]
}

Let us create more Spring Boot applications to monitor via the Spring Boot Admin server created in the above steps. All the Spring Boot applications which will create now will be acted as Spring Boot Admin clients. To make application as Admin client, add the below dependency along with actuator dependency. In this demo, I have created three applications like Eureka Server, Customer Service, and Order Service.

<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-client</artifactId>
<version>1.5.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

Add below property to application.properties file. This property tells where the Spring Boot Admin server is running. Hence the clients will register with the server.

spring.boot.admin.url=http://localhost:1111

Now If we start the Admin Server and other Spring Boot applications we can able to see all the admin clients information in the Admin server dashboard. As we started our admin server on 1111 port in this example we can see dash-board at http ://<host_name>:1111. Below is the screenshot of the Admin Server UI.

Detailed view of an application is given below. In this view, we can see the tail of the log file, metrics, environment variables, log configuration where we can dynamically switch the log levels at the component level, root level or package level and other information.

Now we will see another feature called notifications from Spring Boot Admin. This will notify the administrators when the application status is  DOWN or application status is coming UP. Spring Boot admin supports the below channels to notify the user.

  • Email Notifications
  • Pagerduty Notifications
  • Hipchat Notifications
  • Slack Notifications
  • Let’s Chat Notifications

In this article, we will configure Slack notifications. Add the below properties to the Spring Boot Admin Server’s application.properties file.

spring.boot.admin.notify.slack.webhook-url=https://hooks.slack.com/services/T8787879tttr/B5UM0989988L/0000990999VD1hVt7Go1eL //Slack Webhook URL of a channel
spring.boot.admin.notify.slack.message="*#{application.name}* is *#{to.status}*" //Message to appear in the channel

view raw
Slack Notifications
hosted with ❤ by GitHub

With Spring Boot Admin we are managing all the applications. So we need to secure Spring Boot Admin UI with login feature. Let us enable login feature to Spring Boot Admin server. Here I am going with basic authentication. Add below maven dependencies to the Admin Server module.

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-server-ui-login</artifactId>
<version>1.5.1</version>
</dependency>

Add the below properties to the application.properties file.

security.user.name=admin //user name to authenticate
security.user.password=admin123 //Password to authenticate

As we added security to the Admin Server, Admin clients should be able to connect to the server by authenticating. Hence add the below properties to the Admin client’s application.properties files.

spring.boot.admin.username=admin
spring.boot.admin.password=admin123

There are additional UI features like Hystrix, Turbine UI which we can enable to the dashboard. You can find more details here. The sample code created for this demonstration is available on Github.

Siva Janapati is an Architect with experience in building Cloud Native Microservices architectures, Reactive Systems, Large scale distributed systems, and Serverless Systems. Siva has hands-on in architecture, design, and implementation of scalable systems using Cloud, Java, Go lang, Apache Kafka, Apache Solr, Spring, Spring Boot, Lightbend reactive tech stack, APIGEE edge & on-premise and other open-source, proprietary technologies. Expertise working with and building RESTful, GraphQL APIs. He has successfully delivered multiple applications in retail, telco, and financial services domains. He manages the GitHub(https://github.com/2013techsmarts) where he put the source code of his work related to his blog posts.

Tagged with:
Posted in Spring, Spring Boot

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