trace

Documentation

Overview

Package trace abstracts virtual-kubelet's tracing capabilties into a set of interfaces. While this does allow consumers to use whatever tracing library they want, the primary goal is to share logging data between the configured logger and tracing spans instead of duplicating calls.

Index

• type Span
  • func StartSpan(ctx context.Context, name string) (context.Context, Span)
• type Status
• type Tracer

Types

type Span

type Span interface {
	End()
	SetStatus(Status)

	// WithField and WithFields adds attributes to an entire span
	//
	// This interface is a bit weird, but allows us to manage loggers in the context
	// It is expected that implementations set `log.WithLogger` so the logger stored
	// in the context is updated with the new fields.
	WithField(context.Context, string, interface{}) context.Context
	WithFields(context.Context, log.Fields) context.Context

	// Logger is used to log individual entries.
	// Calls to functions like `WithField` and `WithFields` on the logger should
	// not affect the rest of the span but rather individual entries.
	Logger() log.Logger
}

Span encapsulates a tracing event

func StartSpan

func StartSpan(ctx context.Context, name string) (context.Context, Span)

StartSpan starts a span from the configured default tracer

type Status

type Status = trace.Status

Status is an alias to opencensus's trace status. The main reason we use this instead of implementing our own is library re-use, namely for converting an error to a tracing status. In the future this may be defined completely in this package.

type Tracer

type Tracer interface {
	// StartSpan starts a new span. The span details are emebedded into the returned
	// context
	StartSpan(context.Context, string) (context.Context, Span)
}

Tracer is the interface used for creating a tracing span

var (
	// T is the Tracer to use this should be initialized before starting up
	// virtual-kubelet
	T Tracer = nopTracer{}
)