go.opentelemetry.io/otel/trace

Package trace provides an implementation of the tracing part of the OpenTelemetry API. To participate in distributed traces a Span needs to be created for the operation being performed as part of a traced workflow. In its simplest form: A Tracer is unique to the instrumentation and is used to create Spans. Instrumentation should be designed to accept a TracerProvider from which it can create its own unique Tracer. Alternatively, the registered global TracerProvider from the go.opentelemetry.io/otel package can be used as a default. This package does not conform to the standard Go versioning policy; all of its interfaces may have methods added to them without a package major version bump. This non-standard API evolution could surprise an uninformed implementation author. They could unknowingly build their implementation in a way that would result in a runtime panic for their users that update to the new API. The API is designed to help inform an instrumentation author about this non-standard API evolution. It requires them to choose a default behavior for unimplemented interface methods. There are three behavior choices they can make: All interfaces in this API embed a corresponding interface from go.opentelemetry.io/otel/trace/embedded. If an author wants the default behavior of their implementations to be a compilation failure, signaling to their users they need to update to the latest version of that implementation, they need to embed the corresponding interface from go.opentelemetry.io/otel/trace/embedded in their implementation. For example, If an author wants the default behavior of their implementations to panic, they can embed the API interface directly. This option is not recommended. It will lead to publishing packages that contain runtime panics when users update to newer versions of go.opentelemetry.io/otel/trace, which may be done with a trasitive dependency. Finally, an author can embed another implementation in theirs. The embedded implementation will be used for methods not defined by the author. For example, an author who wants to default to silently dropping the call can use go.opentelemetry.io/otel/trace/noop: It is strongly recommended that authors only embed go.opentelemetry.io/otel/trace/noop if they choose this default behavior. That implementation is the only one OpenTelemetry authors can guarantee will fully implement all the API interfaces when a user updates their API.