Support externalized configuration (e.g. changing server.port externally)

Hi.

It seems that properties like ServerProperties are simply created with constructor: https://github.com/spring-projects/spring-fu/blob/04b317621a88c271e573c84409d89d016f4344c7/jafu/src/main/java/org/springframework/fu/jafu/web/WebFluxServerDsl.java#L51

While “classic” Spring Boot apps create them with Spring Boot’s configuration system, which uses Binder, something like:

binder.bind("server", ServerProperties.class).orElseGet(ServerProperties::new);

Please consider using Binder for them to allow externalized configuration (e.g. changing server.port externally)

[sdeleuze]

For now you can use environnement variables that will be evaluated dynamicaly during startup.

[bsideup]

@sdeleuze still an issue, had to workaround with:

app.enable(WebFluxServerDsl.webFlux(dsl -> {
    try {
        var serverPropertiesField = WebFluxServerDsl.class.getDeclaredField("serverProperties");
        serverPropertiesField.setAccessible(true);
        serverPropertiesField.set(dsl, Binder.get(app.env()).bindOrCreate("server", ServerProperties.class));
    } catch (IllegalAccessException | NoSuchFieldException e) {
        throw new RuntimeException(e);
    }
}));