otelcourier

Documentation

Overview

Package otelcourier instruments the github.com/gojek/courier-go package.

Index

• Constants
• Variables
• func DefaultTopicAttributeTransformer(_ context.Context, topic string) string
• type BucketBoundaries
• type OTel
  • func New(service string, opts ...Option) *OTel
  • func (t *OTel) ApplyMiddlewares(c UseMiddleware)
  • func (t *OTel) PublisherMiddleware(next courier.Publisher) courier.Publisher
  • func (t *OTel) SubscriberMiddleware(next courier.Subscriber) courier.Subscriber
  • func (t *OTel) UnsubscriberMiddleware(next courier.Unsubscriber) courier.Unsubscriber
• type Option
  • func WithInfoHandlerFrom(c interface{ ... }) Option
  • func WithMeterProvider(provider metric.MeterProvider) Option
  • func WithTextMapCarrierExtractFunc(fn func(context.Context) propagation.TextMapCarrier) Option
  • func WithTextMapPropagator(propagator propagation.TextMapPropagator) Option
  • func WithTracerProvider(provider oteltrace.TracerProvider) Option
• type TopicAttributeTransformer
• type UseMiddleware

Examples

• New

Constants

const (
	// MQTTTopic is the attribute key for tracing message topic
	MQTTTopic = attribute.Key("mqtt.topic")
	// MQTTQoS is the attribute key for tracing message qos
	MQTTQoS = attribute.Key("mqtt.qos")
	// MQTTTopicWithQoS is the attribute key for tracing message topic and qos together
	MQTTTopicWithQoS = attribute.Key("mqtt.topicwithqos")
	// MQTTRetained is the attribute key for tracing message retained flag
	MQTTRetained = attribute.Key("mqtt.retained")
	// MQTTClientID is the attribute key for tracing mqtt client id
	MQTTClientID = attribute.Key("mqtt.clientid")
)

Variables

var DisableCallbackTracing = &disableTracePathOpt{traceCallback}

DisableCallbackTracing disables implicit tracing on subscription callbacks.

var DisablePublisherTracing = &disableTracePathOpt{tracePublisher}

DisablePublisherTracing disables courier.Publisher tracing.

var DisableSubscriberTracing = &disableTracePathOpt{traceSubscriber}

DisableSubscriberTracing disables courier.Subscriber tracing.

var DisableUnsubscriberTracing = &disableTracePathOpt{traceUnsubscriber}

DisableUnsubscriberTracing disables courier.Unsubscriber tracing.

Functions

func DefaultTopicAttributeTransformer

func DefaultTopicAttributeTransformer(_ context.Context, topic string) string

DefaultTopicAttributeTransformer is the default transformer for topic attribute.

Types

type BucketBoundaries

type BucketBoundaries struct {
	Publisher, Subscriber, Unsubscriber, Callback []float64
}

BucketBoundaries helps override default histogram bucket boundaries for metrics.

type OTel

type OTel struct {
	// contains filtered or unexported fields
}

OTel implements tracing & metric abilities using OpenTelemetry SDK.

func New

func New(service string, opts ...Option) *OTel

New creates a new OTel with Option(s).

Example

tp := trace.NewTracerProvider()
defer tp.Shutdown(context.Background())

exporter, err := prometheus.New(
/* Add a non-default prometheus registry here with `prometheus.WithRegisterer` option, if needed. */
)
if err != nil {
	panic(err)
}
mp := metric.NewMeterProvider(metric.WithReader(exporter))

otel.SetTracerProvider(tp)
otel.SetMeterProvider(mp)
otel.SetTextMapPropagator(&propagation.TraceContext{})

metricLabelMapper := otelcourier.TopicAttributeTransformer(func(ctx context.Context, topic string) string {
	if strings.HasPrefix(topic, "test") {
		return "test"
	}

	return "other"
})

c, _ := courier.NewClient()
otelcourier.New(
	"service-name",
	// Use this to also track active connections.
	otelcourier.WithInfoHandlerFrom(c),
	metricLabelMapper,
).ApplyMiddlewares(c)

if err := c.Start(); err != nil {
	panic(err)
}

ctx, _ := signal.NotifyContext(context.Background(), os.Interrupt, os.Kill)

if err := c.Publish(
	context.Background(), "test-topic", "message", courier.QOSOne); err != nil {
	panic(err)
}

if err := c.Publish(
	context.Background(), "other-topic", "message", courier.QOSOne); err != nil {
	panic(err)
}

// Here, you can expose the metrics at /metrics endpoint for prometheus.DefaultRegisterer.

<-ctx.Done()

c.Stop()

func (*OTel) ApplyMiddlewares

func (t *OTel) ApplyMiddlewares(c UseMiddleware)

ApplyMiddlewares will instrument all the operations of a UseMiddleware instance according to Option(s) used.

func (*OTel) PublisherMiddleware

func (t *OTel) PublisherMiddleware(next courier.Publisher) courier.Publisher

PublisherMiddleware is a courier.PublisherMiddlewareFunc for tracing publish calls.

func (*OTel) SubscriberMiddleware

func (t *OTel) SubscriberMiddleware(next courier.Subscriber) courier.Subscriber

SubscriberMiddleware is a courier.SubscriberMiddlewareFunc for tracing subscribe calls.

func (*OTel) UnsubscriberMiddleware

func (t *OTel) UnsubscriberMiddleware(next courier.Unsubscriber) courier.Unsubscriber

UnsubscriberMiddleware is a courier.UnsubscriberMiddlewareFunc for tracing unsubscribe calls.

type Option

type Option interface {
	// contains filtered or unexported methods
}

Option helps configure trace options.

func WithInfoHandlerFrom

func WithInfoHandlerFrom(c interface{ InfoHandler() http.Handler }) Option

WithInfoHandlerFrom is used to specify the handler which should be used to extract client information from the courier.Client instance.

func WithMeterProvider

func WithMeterProvider(provider metric.MeterProvider) Option

WithMeterProvider specifies a meter provider to use for creating a meter. If none is specified, the global provider is used.

func WithTextMapCarrierExtractFunc

func WithTextMapCarrierExtractFunc(fn func(context.Context) propagation.TextMapCarrier) Option

WithTextMapCarrierExtractFunc is used to specify the function which should be used to extract propagation.TextMapCarrier from the ongoing context.Context.

func WithTextMapPropagator

func WithTextMapPropagator(propagator propagation.TextMapPropagator) Option

WithTextMapPropagator specifies the propagator to use for extracting/injecting key-value texts. If none is specified, the global provider is used.

func WithTracerProvider

func WithTracerProvider(provider oteltrace.TracerProvider) Option

WithTracerProvider specifies a tracer provider to use for creating a tracer. If none is specified, the global provider is used.

type TopicAttributeTransformer

type TopicAttributeTransformer func(context.Context, string) string

TopicAttributeTransformer helps transform topic before making an attribute for it. It is used in metric recording only. Traces use the original topic.

type UseMiddleware

type UseMiddleware interface {
	UsePublisherMiddleware(mwf ...courier.PublisherMiddlewareFunc)
	UseSubscriberMiddleware(mwf ...courier.SubscriberMiddlewareFunc)
	UseUnsubscriberMiddleware(mwf ...courier.UnsubscriberMiddlewareFunc)
}

UseMiddleware is an interface that defines the methods to apply middlewares to a courier.Client or similar instance.