otel

README

OpenTelemetry-Go

The Go OpenTelemetry implementation.

Project Status

Warning: this project is currently in a pre-GA phase. Backwards incompatible changes may be introduced in subsequent minor version releases as we work to track the evolving OpenTelemetry specification and user feedback.

Our progress towards a GA release candidate is tracked in this project board. This release candidate will follow semantic versioning and will be released with a major version greater than zero.

Progress and status specific to this repository is tracked in our local project boards and milestones.

Project versioning information and stability guarantees can be found in the versioning documentation.

Getting Started

You can find a getting started guide on opentelemetry.io.

OpenTelemetry's goal is to provide a single set of APIs to capture distributed traces and metrics from your application and send them to an observability platform. This project allows you to do just that for applications written in Go. There are two steps to this process: instrument your application, and configure an exporter.

Instrumentation

To start capturing distributed traces and metric events from your application it first needs to be instrumented. The easiest way to do this is by using an instrumentation library for your code. Be sure to check out the officially supported instrumentation libraries.

If you need to extend the telemetry an instrumentation library provides or want to build your own instrumentation for your application directly you will need to use the go.opentelemetry.io/otel/api package. The included examples are a good way to see some practical uses of this process.

Export

Now that your application is instrumented to collect telemetry, it needs an export pipeline to send that telemetry to an observability platform.

You can find officially supported exporters here and in the companion contrib repository. Additionally, there are many vendor specific or 3rd party exporters for OpenTelemetry. These exporters are broken down by trace and metric support.

Contributing

See the contributing documentation.

Documentation

Overview

Package otel provides global access to the OpenTelemetry API. The subpackages of the otel package provide an implementation of the OpenTelemetry API.

This package is currently in a pre-GA phase. Backwards incompatible changes may be introduced in subsequent minor version releases as we work to track the evolving OpenTelemetry specification and user feedback.

The provided API is used to instrument code and measure data about that code's performance and operation. The measured data, by default, is not processed or transmitted anywhere. An implementation of the OpenTelemetry SDK, like the default SDK implementation (go.opentelemetry.io/otel/sdk), and associated exporters are used to process and transport this data.

To read the getting started guide, see https://opentelemetry.io/docs/go/getting-started/.

To read more about tracing, see go.opentelemetry.io/otel/trace.

To read more about metrics, see go.opentelemetry.io/otel/metric.

To read more about propagation, see go.opentelemetry.io/otel/propagation and go.opentelemetry.io/otel/baggage.

Index

• func GetMeterProvider() metric.MeterProvider
• func GetTextMapPropagator() propagation.TextMapPropagator
• func GetTracerProvider() trace.TracerProvider
• func Handle(err error)
• func Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter
• func SetErrorHandler(h ErrorHandler)
• func SetMeterProvider(mp metric.MeterProvider)
• func SetTextMapPropagator(propagator propagation.TextMapPropagator)
• func SetTracerProvider(tp trace.TracerProvider)
• func Tracer(name string) trace.Tracer
• func Version() string
• type ErrorHandler
  • func GetErrorHandler() ErrorHandler

Functions

func GetMeterProvider

func GetMeterProvider() metric.MeterProvider

GetMeterProvider returns the registered global meter provider. If none is registered then a default meter provider is returned that forwards the Meter interface to the first registered Meter.

Use the meter provider to create a named meter. E.g.

meter := global.MeterProvider().Meter("example.com/foo")

or

meter := global.Meter("example.com/foo")

func GetTextMapPropagator

func GetTextMapPropagator() propagation.TextMapPropagator

GetTextMapPropagator returns the global TextMapPropagator. If none has been set, a No-Op TextMapPropagator is returned.

func GetTracerProvider

func GetTracerProvider() trace.TracerProvider

GetTracerProvider returns the registered global trace provider. If none is registered then an instance of NoopTracerProvider is returned.

Use the trace provider to create a named tracer. E.g.

tracer := global.GetTracerProvider().Tracer("example.com/foo")

or

tracer := global.Tracer("example.com/foo")

func Handle

func Handle(err error)

Handle is a convience function for ErrorHandler().Handle(err)

func Meter

func Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter

Meter creates an implementation of the Meter interface from the global MeterProvider. The instrumentationName must be the name of the library providing instrumentation. This name may be the same as the instrumented code only if that code provides built-in instrumentation. If the instrumentationName is empty, then a implementation defined default name will be used instead.

This is short for MeterProvider().Meter(name)

func SetErrorHandler

func SetErrorHandler(h ErrorHandler)

SetErrorHandler sets the global ErrorHandler to be h.

func SetMeterProvider

func SetMeterProvider(mp metric.MeterProvider)

SetMeterProvider registers `mp` as the global meter provider.

func SetTextMapPropagator

func SetTextMapPropagator(propagator propagation.TextMapPropagator)

SetTextMapPropagator sets propagator as the global TextMapPropagator.

func SetTracerProvider

func SetTracerProvider(tp trace.TracerProvider)

SetTracerProvider registers `tp` as the global trace provider.

func Tracer

func Tracer(name string) trace.Tracer

Tracer creates a named tracer that implements Tracer interface. If the name is an empty string then provider uses default name.

This is short for TracerProvider().Tracer(name)

func Version

func Version() string

Version is the current release version of OpenTelemetry in use.

Types

type ErrorHandler

type ErrorHandler interface {
	// Handle handles any error deemed irremediable by an OpenTelemetry
	// component.
	Handle(error)
}

ErrorHandler handles irremediable events.

func GetErrorHandler

func GetErrorHandler() ErrorHandler

GetErrorHandler returns the global ErrorHandler instance. If no ErrorHandler instance has been set (`SetErrorHandler`), the default ErrorHandler which logs errors to STDERR is returned.