Question about console-subscriber layer interactions with other layers that might call tokio::spawn internally.

[merc1031]

I have something (simplified here) like this

    let mut layers = Vec::new();
    // conditionally make console_subscriber layer
    if using_console {
        // console_subscriber code
        layers.push(console_subscriber.boxed());
    };

    let env_filter_builder = EnvFilter::builder();
    let layer = reload::Layer::new(layer);

    // Generate `apm_layer` and `logging_layer`
    // [1] `apm_layer` is the layer that calls tokio::spawn to create a named bg thread

    fn console_filter(meta: &tracing::Metadata<'_>) -> bool {
        if meta.is_event() {
            return !(meta.target().starts_with("runtime") || meta.target().starts_with("tokio"));
        }

        !(meta.name().starts_with("runtime.") || meta.target().starts_with("tokio"))
    }

    let apm_layer = apm_layer.with_filter(FilterFn::new(console_filter));
    let logging_layer = logging_layer.with_filter(FilterFn::new(console_filter));


    layers.push(apm_layer.boxed());
    layers.push(logging_layer.boxed());
    layers.push(layer.boxed());

    tracing_subscriber::registry().with(layers).init();

My issue is the console_subscriber does not see the tokio::spawned background task in [1] apm_layer.
Due to not being able to setup the layers in phases, I can't seem to figure out how to acheive this.

I have attempted to use a reload::Layer around a Option<Vec<Layer>> to defer adding apm_layer and logging_layer until after .init but i get
a none to suprising panic, since the layer is initially added as None which skips a bunch of needed setup

a `Filtered` layer was used, but it had no `FilterId`; was it registered with the subscriber?

I'm not sure how to work around this at this point. Its not the biggest deal, but essentially all tokio::spawn before .init are not visible in the tokio-console.

Thanks

[hds]

The issue is that you can't add a filter after the subscriber has already been initialised.

It might be possible to have a reload layer around an Option<Layer> and then add the filter to the reload layer (so that the filter is always present, even before the actual layer is set). However, I haven't tried this myself.

[hds]

Also. It's better to add the layers individually with a .with(..) call for each layer. That way you don't need to box them either.