Allow specifying the port (or nic) for Spring Boot Actuator

[trustin]

WebOperationService is currently always bound to Server's all ports. It'd be nice if there's a way to limit/disable WebOperationService for other ports than a specific port/remoteAddr/NIC.

Armeria currently is not capable of binding a service to a specific port only, but we could simply respond with 404 if the request came from a wrong port. Internally this could be implemented as a generic decorator that works for any HttpService.

As a workaround, a user can specify a custom route decorator:

@Bean
public ArmeriaServerConfigurator secureActuator() {
    return builder -> {
		builder.routeDecorator()
               .pathPrefix("/internal")
               .build((delegate, ctx, req) -> {
                   final InetSocketAddress laddr = ctx.localAddress();
                   if (laddr.getPort() != INTERNAL_PORT) {
                       return HttpResponse.of(404);
                   } else {
                       return delegate.serve(ctx, req);
                   }
               });
    };
}

[heowc]

In spring boot actuator, the base path of the provided actuator is /actuator.
In addition, is there a need to include internal/docs, internal/metrics and internal/healthcheck in armeria?

[trustin]

@heowc Yes. It'd be nice to provide this feature as a part of the core, too.