opentelemetry

README

OpenTelemetry Helper functions

Open Telemetry http middleware. This package provides an instrumentation for middleware that can be used to trace HTTP requests.

otelmiddleware

Package otelmiddleware provides middleware for wrapping http.Server handlers with Open Telemetry tracing support.

The trace.Span is decorated with standard metadata extracted from the http.Request injected into the middleware. the basic information is extracted using the OpenTelemetry semconv package.

When a span gets initialized it uses the following slice of trace.SpanStartOption

opts := []trace.SpanStartOption{
    trace.WithAttributes(semconv.NetAttributesFromHTTPRequest("tcp", r)...),
    trace.WithAttributes(semconv.EndUserAttributesFromHTTPRequest(r)...),
    trace.WithAttributes(semconv.HTTPServerAttributesFromHTTPRequest(r.Host, extractRoute(r.RequestURI), r)...),
    trace.WithAttributes(semconv.HTTPClientAttributesFromHTTPRequest(r)...),
    trace.WithAttributes(semconv.TelemetrySDKLanguageGo),
    trace.WithSpanKind(trace.SpanKindClient),
}

The slice can be extended using the WithAttributes TraceOption function.

After these options are applied a new span is created and the middleware will pass the http.ResponseWriter and http.Request to the next http.Handler.

Functions

func TraceWithOptions(opt ...TraceOption) func(next http.Handler) http.Handler
func Trace(next http.Handler) http.Handler
func WithAttributes(attributes ...attribute.KeyValue) TraceOption
func WithPropagator(p propagation.TextMapPropagator) TraceOption
func WithServiceName(serviceName string) TraceOption
func WithTracer(tracer trace.Tracer) TraceOption

Types

type TraceOption func(*traceConfig)

Structs

type traceConfig struct {
    tracer trace.Tracer
    propagator propagation.TextMapPropagator
    attributes []attribute.KeyValue
    serviceName string
}

otelzerolog

Package otelzerolog provides a function to extend structured logs using zerolog with the Open Telemetry trace related context.

The github.com/rs/zerolog zerolog.Event is decorated with standard metadata extracted from the trace.SpanContext, a traceID, spanID and additional information is injected into a log.

The initialization uses file level configuration to set defaults for the function to use. SetLogOptions can overwrite the defaults.

When the configuration is done AddTracingContext and AddTracingContextWithAttributes decorate zerolog logs with data from the trace context. A zeroLog.Event can be passed by using log.Info().Func(AddTracingContext(span)).Msg("") for example.

Functions

func SetLogOptions(options ...LogOption)
func WithTraceID(traceID string) LogOption
func WithSpanID(spanID string) LogOption
func WithServiceName(serviceName string) LogOption
func WithAttributePrefix(prefix string) LogOption
func WithAttributes(attributes ...attribute.KeyValue) LogOption
func AddTracingContext(span trace.Span, err ...error) func(event *zerolog.Event)
func AddTracingContextWithAttributes(span trace.Span, attributes []attribute.KeyValue, err ...error) func(event *zerolog.Event)

Types

type LogOption func(*logConfig)

Structs

type logConfig struct {
	attributes      []attribute.KeyValue
	serviceName     string
	traceId         string
	spanId          string
	attributePrefix string
}