You can acquire a io.helidon.discovery.Discovery object by injecting it into your Helidon SE application:

import java.util.Objects;
import io.helidon.discovery.Discovery;
import io.helidon.service.registry.Service;

public class MyClass {

    private final Discovery discovery;

    @Service.Inject 
    public MyClass(Discovery discovery) { 
        this.discovery = Objects.requireNonNull(discovery, "discovery"); 
    }

}

• Use the io.helidon.service.registry.Service.Inject annotation to indicate that this constructor has an injection point.
• Here, the discovery constructor parameter is the injection point and will receive a non-null instance of io.helidon.discovery.Discovery.
• The constructor explicitly assigns the injected reference to the discovery instance field.

You can acquire a io.helidon.discovery.Discovery object by using the Helidon Service Registry via the io.helidon.service.registry.Services façade:

import io.helidon.discovery.Discovery;
import io.helidon.service.registry.Services;

public class MyOtherClass {

    private final Discovery discovery;

    public MyOtherClass() {
        this.discovery = Services.get(Discovery.class); 
    }

}

• Use the io.helidon.service.registry.Services#get(Class) method to acquire an instance of the io.helidon.discovery.Discovery class, and assign it to an instance field.

To use the Helidon Eureka Discovery provider, add the following dependency to your project’s pom.xml (see Managing Dependencies).

<dependencies>
    <dependency>
        <groupId>io.helidon.discovery.providers</groupId>
        <artifactId>helidon-discovery-providers-eureka</artifactId> 
        <scope>runtime</scope> 
    </dependency>
</dependencies>

• Helidon Eureka Discovery provider dependency.
• The scope for the provider. Use runtime if you have no interest in provider-specific classes and methods (the most common case). Use compile if you plan to call provider-specific methods.

The Helidon Eureka Discovery provider can be configured using Helidon Config. Examples shown below are in YAML, but are expressible in any format and any location that Helidon Config supports.

Configuration for the Helidon Eureka Discovery provider is found under a top-level discovery.eureka key path.

Generated documentation normatively describing the provider’s configuration in full can be found in Helidon’s Configuration Reference. Some common usages and examples are detailed below.

Configuring the Location of the Eureka Server

discovery: 
  eureka: 
    client: 
      base-uri: "http://example.com:8761/eureka" 

Configuring Caching

discovery: 
  eureka: 
    cache: 
      compute-changes: true 
      defer-sync: false 
      enabled: true 
      fetch-thread-name: "Eureka registry fetch thread" 
      sync-interval: "PT30S" 

Configuring IP Address vs. Hostname

discovery: 
  eureka: 
    preferIpAddress: false 

Disabling the Provider

discovery: 
  eureka: 
    enabled: false 

Users of the Helidon Eureka Discovery provider may also be interested in the (related) Eureka Server Service Instance Registration feature.

To include the Helidon Web Client Discovery integration in your project, you add the Web Client Discovery integration dependency as well as a Discovery provider dependency (see Managing Dependencies):

<dependencies>
    <dependency>
        <groupId>io.helidon.webclient</groupId>
        <artifactId>helidon-webclient-discovery</artifactId> 
        <scope>runtime</scope> 
    </dependency>
    <dependency>
        <groupId>io.helidon.discovery.providers</groupId>
        <artifactId>helidon-discovery-providers-eureka</artifactId> 
        <scope>runtime</scope> 
    </dependency>
</dependencies>

• Helidon Web Client Discovery integration dependency.
• The scope for the integration. runtime since the integration is never required at compile time.
• Helidon Eureka Discovery provider dependency (for example).
• The scope for the provider. Use runtime if you have no interest in provider-specific classes and methods (the most common case). Use compile if you plan to call provider-specific methods.

The behavior of the Web Client Discovery integration is fully specified and documented.

The Helidon Web Client Discovery integration can be configured using Helidon Config. Examples shown below are in YAML, but are expressible in any format and any location that Helidon Config supports.

Because the Helidon Web Client Discovery integration is fundamentally a Web Client Service, you configure it under a Web Client’s services configuration node:

webclient:
  services:
    discovery: 

• Indicates that the Web Client Discovery integration should apply to this Web Client configuration. More configuration is required; see below.

You also configure the Discovery provider in use following its documentation. See, for example, Eureka configuration.

To mark URIs requested by a Web Client as subject to discovery, and to use discovery names appropriate for them, you need to configure prefix URIs. URIs that match no prefix will not be subject to discovery:

webclient:
  services:
    discovery:
      prefix-uris:
        EXAMPLE: "https://example.com:443/" 
        TEST: "https://test.example.com:443/"  

• Indicates that URIs starting with https://example.com:443/ will be subject to discovery, using the discovery name of EXAMPLE
• Indicates that URIs starting with https://test.example.com:443/ will be subject to discovery, using the discovery name of TEST
• URIs that begin with text other than https://example.com:443/ or https://test.example.com:443/ will not be subject to discovery