baggage

type Headers ¶

type Headers map[string]string

Headers is a header map in authz convention – keys are lowercase.

type Prefixed ¶

type Prefixed struct {
	// Header prefix, eg. "uberctx-" – in lower-case, as per envoy's authz
	// convention – (note that this differs from golang's conventions))
	Prefix string
}

Prefixed puts each flow label into a separate header. Header name is concatenation of Prefix and flow label name.

func (p Prefixed) Extract(headers Headers) flowlabel.FlowLabels

func (p Prefixed) Inject(
	flowLabels flowlabel.FlowLabels,
	headers Headers,
) ([]*envoy_core.HeaderValueOption, error)

type Propagator ¶

type Propagator interface {
	// Extract extracts flow labels from headers
	//
	// The headers are expected to be in envoy's authz convention – with
	// lower-case keys
	Extract(headers Headers) flowlabel.FlowLabels

	// Inject emits instructions for envoy how to inject flow labels into
	// headers based on given flow labels and existing headers
	//
	// The returned list is expected to be put in
	// CheckResponse.OkHttpResponse.Headers, so that envoy will take care of
	// injecting appropriate headers.
	Inject(flowLabels flowlabel.FlowLabels, headers Headers) ([]*envoy_core.HeaderValueOption, error)
}

Propagator defines how to extract flow labels (baggage) from and put into headers

This interface is similar to go.opentelemetry.io/otel/propagation.TextMapPropagator: https://github.com/open-telemetry/opentelemetry-go/blob/v1.2.0/propagation/propagation.go#L91-L111 but is designed to use authz-compatible types and conventions.

type W3Baggage ¶

type W3Baggage struct{}

W3Baggage handles baggage propagation in a single `baggage` header, as described in https://www.w3.org/TR/baggage/

All baggage items are mapped to flow labels 1:1. This could be tweaked in future: * we can use some prefixing/filtering, * alternatively, we could put _all_ flow labels as a _single_ baggage item (eg. Fn-flow).

func (b W3Baggage) Extract(headers Headers) flowlabel.FlowLabels

func (b W3Baggage) Inject(
	flowLabels flowlabel.FlowLabels,
	headers Headers,
) ([]*envoy_core.HeaderValueOption, error)