Add support for sending additional HTTP or gRPC headers which
can be used for authentication or other additional information
for the tracing system without having to set up a local instance
of the OpenTelemetry Collector to add these headers.
Example with Dash0:
```yaml
tracing-enabled: false
tracing-transport: "grpc"
tracing-endpoint: "ingress.eu-west-1.aws.dash0.com:4317"
tracing-headers:
"Authorization": "Bearer DASH0_AUTH_TOKEN"
"Dash0-Dataset": "gotosocial"
```
Example with Honeycomb:
```yaml
tracing-enabled: false
tracing-transport: "grpc"
tracing-endpoint: "api.honeycomb.io:443"
tracing-headers:
"x-honeycomb-team": "YOUR_API_KEY"
"x-honeycomb-dataset": "YOUR_DATASET"
```
The OpenTelemetry SDK is very strict about the schema version when
the `Resource` is initialized.
Specifically, different schema versions _CANNOT_ be mixed, and since
the default SDK resource (which is merged with the user-defined one)
defines a schema URL, the `semconv` imports are really prone to being
out-of-sync.
The best way to avoid this is to merge a _schemaless_ resource. This
is fine...there's plenty of other ways to get `semconv` out of sync,
and the core service attributes (e.g. `service.name`) should not ever
change.
Additionally, any errors here are now propagated so that they'll be
visible instead of silently swallowed.
* [feature] Add http trace exporter, drop Jaeger
Jaeger supports ingesting traces using the OpenTelemetry gRPC or HTTP
methods. The Jaeger project has deprecated the old jaeger transport.
* Add support for submitting traces over HTTP
* Drop support for the old Jaeger protocol
* Upgrade the trace libraries to v1.17
Fixes: #2176Fixes: #2179
c.FullPath() is the empty string if a request doesn't match any route on
our mux. In those cases, there's no value in emitting a trace. The trace
will be empty, containing no other information beyond the fact that we
didn't match a route. Since Gin breaks off the processing early we don't
need to trace this request as it won't do anything and consumes no
further resources.
The 404 will still be emitted by our logs and will be visible from a
reverse proxy too.
