allow basic authentication header on injected @RESTClients

[jlf-ibm]

Is your feature request related to a problem? Please describe.

We already support attaching JWTs to RESTClient instances. Allow another type in that same vein, for setting HTTP Basic Authentication header.

Describe the solution you'd like

@RESTClient
@BasicAuthConfig(username = "user", password="pass")
MyClientResource myClient;

Describe alternatives you've considered

The only alternative is to completely change my application to use JWTs instead of in-container basic authentication.

Additional context

Open Liberty 19 with standard LDAP registry and web.xml with ALL_CONFIDENTIAL protecting /*

[aguibert]

Thanks for opening this @jlf-ibm, sounds like a good use case to support. I wonder if we should use a more generic annotation approach so we don't need to make a new annotation for every authentication or header type?

[jlf-ibm]

Maybe if we add a third? I leave it to you. It'd be nice to just get this specific in sooner than a generic later.

[aguibert]

Hi @jlf-ibm, I wrote up a proposed PR here and will merge it soon:
#158