Spring Boot Admin – Client Applications

Show Version in Application List

For Spring Boot applications the easiest way to show the version, is to use the build-info goal from the spring-boot-maven-plugin, which generates the META-INF/build-info.properties. See also the Spring Boot Reference Guide.

For non-Spring Boot applications you can either add a version or build.version to the registration metadata and the version will show up in the application list.

pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <executions>
                <execution>
                    <goals>
                        <goal>build-info</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

To generate the build-info in a gradle project, add the following snippet to your build.gradle:

build.gradle

springBoot {
        buildInfo()
}

JMX-Bean Management

To interact with JMX-beans in the admin UI you have to include Jolokia in your application and expose it via the actuator endpoint. As Jolokia is servlet based there is no support for reactive applications.

You might want to set spring.jmx.enabled=true if you want to expose Spring beans via JMX.

Spring Boot 3 App

Spring Boot 3 does not support Jolokia directly, you need a separate dependency for Spring Boot 3 based applications. See https://jolokia.org/reference/html/manual/spring.html for more details.

pom.xml

<dependency>
    <groupId>org.jolokia</groupId>
    <artifactId>jolokia-support-spring</artifactId>
    <version>2.1.0</version>
</dependency>

Spring Boot 2 App

You can still monitor Spring Boot 2 applications with Jolokia endpoint using a Spring Boot Admin 3 server. Spring Boot 2 provided the actuator itself, so you only the need the plain jolokia dependency.

pom.xml

<dependency>
    <groupId>org.jolokia</groupId>
    <artifactId>jolokia-core</artifactId>
</dependency>

Logfile Viewer

By default the logfile is not accessible via actuator endpoints and therefore not visible in Spring Boot Admin. In order to enable the logfile actuator endpoint you need to configure Spring Boot to write a logfile, either by setting logging.file.path or logging.file.name.

Spring Boot Admin will detect everything that looks like an URL and render it as hyperlink.

ANSI color-escapes are also supported. You need to set a custom file log pattern as Spring Boot’s default one doesn’t use colors.

To enforce the use of ANSI-colored output, set spring.output.ansi.enabled=ALWAYS. Otherwise Spring tries to detect if ANSI-colored output is available and might disable it.

application.properties

logging.file.name=/var/log/sample-boot-application.log (1)
logging.pattern.file=%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(%5p) %clr(${PID}){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n%wEx (2)

1	Destination the logfile is written to. Enables the logfile actuator endpoint.
2	File log pattern using ANSI colors.

Show Tags per Instance

Tags are a way to add visual markers per instance, they will appear in the application list as well as in the instance view. By default no tags are added to instances, and it’s up to the client to specify the desired tags by adding the information to the metadata or info endpoint.

application.properties

#using the metadata
spring.boot.admin.client.instance.metadata.tags.environment=test

#using the info endpoint
info.tags.environment=test

Spring Boot Admin Client

The Spring Boot Admin Client registers the application at the admin server. This is done by periodically doing a HTTP post request to the SBA Server providing information about the application.

	There are plenty of properties to influence the way how the SBA Client registers your application. In case that doesn’t fit your needs, you can provide your own `ApplicationFactory` implementation.

Table 1. Spring Boot Admin Client configuration options
Property name	Description	Default value
spring.boot.admin.client.enabled	Enables the Spring Boot Admin Client.	`true`
spring.boot.admin.client.url	Comma separated ordered list of URLs of the Spring Boot Admin server to register at. This triggers the AutoConfiguration. Mandatory.
spring.boot.admin.client.api-path	Http-path of registration endpoint at your admin server.	`"instances"`
spring.boot.admin.client.username spring.boot.admin.client.password	Username and password in case the SBA Server api is protected with HTTP Basic authentication.
spring.boot.admin.client.period	Interval for repeating the registration (in ms).	`10,000`
spring.boot.admin.client.connect-timeout	Connect timeout for the registration (in ms).	`5,000`
spring.boot.admin.client.read-timeout	Read timeout for the registration (in ms).	`5,000`
spring.boot.admin.client.auto-registration	If set to true the periodic task to register the application is automatically scheduled after the application is ready.	`true`
spring.boot.admin.client.auto-deregistration	Switch to enable auto-deregistration at Spring Boot Admin server when context is closed. If the value is unset the feature is active if a running CloudPlatform was detected.	`null`
spring.boot.admin.client.register-once	If set to true the client will only register against one admin server (in order defined by `spring.boot.admin.instance.url`); if that admin server goes down, will automatically register against the next admin server. If false, will register against all admin servers.	`true`
spring.boot.admin.client.instance.health-url	Health-url to register with. Can be overridden in case the reachable URL is different (e.g. Docker). Must be unique in registry.	Guessed based on management-base-url and `endpoints.health.id`.
spring.boot.admin.client.instance.management-base-url	Base url for computing the management-url to register with. The path is inferred at runtime, and appended to the base url.	Guessed based on `management.server.port`, service-url and `server.servlet-path`.
spring.boot.admin.client.instance.management-url	Management-url to register with. Can be overridden in case the reachable url is different (e.g. Docker).	Guessed based on management-base-url and `management.server.base-path`.
spring.boot.admin.client.instance.service-base-url	Base url for computing the service-url to register with. The path is inferred at runtime, and appended to the base url. In Cloudfoundry environments you can switching to https like this: `spring.boot.admin.client.instance.service-base-url=https://${vcap.application.uris[0]}`	Guessed based on hostname, `server.port`.
spring.boot.admin.client.instance.service-url	Service-url to register with. Can be overridden in case the reachable url is different (e.g. Docker).	Guessed based on service-base-url and `server.context-path`.
spring.boot.admin.client.instance.service-path	Service-path to register with. Can be overridden in case the reachable path is different (e.g. context-path set programmatically).	/
spring.boot.admin.client.instance.name	Name to register with.	`${spring.application.name}` if set, `"spring-boot-application"` otherwise.
spring.boot.admin.client.instance.service-host-type	Select which information should be considered when sending the host of a service: * `IP`: Uses the IP returned by `InetAddress.getHostAddress()` * `HOST_NAME`: Uses the host name of a single machine returned by `InetAddress.getHostName()` * `CANONICAL_HOST_NAME`: Uses the FQDN returned by `InetAddress.geCanonicalHostName()` If `server.address` or `management.server.address` is set in the service, the value will overrule this property.	`CANONICAL_HOST_NAME`
spring.boot.admin.client.instance.metadata.*	Metadata key-value-pairs to be associated with this instance.
spring.boot.admin.client.instance.metadata.tags.*	Tags as key-value-pairs to be associated with this instance.

Table 2. Instance metadata options
Key	Value	Default value
user.name user.password	Credentials being used to access the endpoints.