Minor documentation typos

[abh]

No description provided.

[abh]

I was getting Plack::Middleware::OpenTelemetry ready for a release and was trying to add some options for it, so really what I wanted to figure out was how to add attributes to the resource. :-)

I couldn't figure out how to do it in code without setting the ENV{}.

Following the documentation I adjusted, for example

my $resource = OpenTelemetry::SDK::Resource->new(attributes => {foo => 12311});

OpenTelemetry->tracer_provider =
  OpenTelemetry::SDK::Trace::TracerProvider->new(resource => $resource,);

then also requires me to copy / redo the work done in OpenTelemetry::SDK to setup the defaults.

Using $ENV{OTEL_RESOURCE_ATTRIBUTES} works in my example program; but in "real code" some of the attributes are difficult to get to in a BEGIN{} block, so another practical API would be nice.

(Or an example of how it already works if I'm just missing how to do it!)

[abh]

I tried making the resource thing work by providing the option when creating the span, but best I can tell it gets lost somewhere (and then I ran out of time for today):

https://github.com/abh/Plack-Middleware-OpenTelemetry/blob/89e63a65187e6d80fcf9552c6958f5126a3c25c6/lib/Plack/Middleware/OpenTelemetry.pm#L40

[jjatria]

Thanks! I'll have to think a little about the resources, but the typos are well spotted 👍

[jjatria]

my $resource;
if (my $a = $self->resource_attributes) {
    my $resource = OpenTelemetry::SDK::Resource->new()
      ->merge(OpenTelemetry::SDK::Resource->new(empty => 1, attributes => $a));
}

In this example, the problem is that the new resource you create gets assigned to a new $resource that you declare within the scope of the if block. As soon as this block finishes, you are back to the $resource variable from the outer scope, which you never assigned to. Try removing the my inside the block.

Also: the empty parameter is undocumented because I'm not sure it's going to stay (that was me working around some Object::Pad limitations). What will stay is the empty constructor, so you should probably do

-OpenTelemetry::SDK::Resource->new(empty => 1, attributes => $a)
+OpenTelemetry::SDK::Resource->empty(attributes => $a)

Incidentally, your code will create a new resource every time the middleware is called, even though the resource attributes (I imagine) won't change.