Struct HeaderInjector

pub struct HeaderInjector<'a>(/* private fields */);

Injects the TextMapPropagator to propagate trace parent information in HTTP headers.

This propagation is useful when consumers of the HTTP response want to link up their span data with the data produced in the Tower Layer. A concrete usage example is available in the TraceService::call implementation for TraceService.

This is pretty much a copy-pasted version of the HeaderInjector from the opentelemetry_http crate. However, we cannot use this crate, as it uses an outdated version of the underlying http crate.

Implementations

impl<'a> HeaderInjector<'a>

pub fn new(headers: &'a mut HeaderMap) -> Self

Create a new header injecttor from a mutable reference to [HeaderMap].

pub fn inject_context(&mut self, cx: &Context)

Inject the TextMapPropagator into the HTTP headers.

Trait Implementations

impl Injector for HeaderInjector<'_>

fn set(&mut self, key: &str, value: String)

Add a key and value to the underlying data.