Support custom tags in NettyEventExecutorMetrics

[jbertram]

I would like to be able to set custom tags on NettyEventExecutorMetrics like is possible with most of the other MeterBinder implementations.

I set common tags on all the meters I register, but I can't modify the configuration of the MeterRegistry as it may be injected and using something like MeterRegistry.config().commonTags(...) would potentially modify other meters that should not, in fact, have those tags.

[jonatan-ivanov]

Thanks for the issue and the PR!

I think this is a valid feature request but just let you know, you can do this today using a MeterFilter, see the docs: https://docs.micrometer.io/micrometer/reference/concepts/meter-filters.html#_transforming_metrics

registry.config().meterFilter(new MeterFilter() {
    @Override
    public Meter.Id map(Meter.Id id) {
        if(id.getName().startsWith("test")) {
            return id.withTag("extra", "value"); 
        } 

        return id;
    }
});

[jbertram]

@jonatan-ivanov, thanks for the feedback! Currently I'm using a MeterFilter almost exactly like that as a workaround, but I'd rather have a 1-line solution that's consistent with the way that I'm configuring the other MeterBinders than a 10-line solution that's unique.