MicroProfile Rest Client - Support wildcard in URL/URI properties key

[tvallin]

Environment Details

• Helidon Version: 4.x
• Helidon MP
• JDK version: 21
• OS: n/a
• Docker version (if applicable): n/a

---

Problem Description

Currently, Helidon users can set URL by setting $restClient/mp-rest/url property where restClient is the client alias or the class name.

The spec mentions */mp-rest/url property to set the client baseUrl and we currently don't support it.
It is not required so this issue is an enhancement proposal.

(Same applies for URI)

Steps to reproduce

Example of how it could looks like from the MP quickstart:

Add a rest client

@Path("/greet")
@RegisterRestClient(configKey="client", baseUri = "http://localhost:8080")
public interface MyRestClient {

    @GET
    GreetingMessage getDefaultMessage();
}

Add this test class

@HelidonTest
@AddConfig(key = "*/mp-rest/url", value = "http://localhost:8000")
public class MpRestClientConfigTest {

    @Inject
    @RestClient
    MyRestClient client;

    @Test
    void test() {
        client.getDefaultMessage();
    }

}