prober

Documentation

Overview

Package prober contains functionality for implementing probing in knative serving.

Index

• func Do(ctx context.Context, transport http.RoundTripper, target, headerValue string, ...) (bool, error)
• type Done
• type Manager
  • func New(cb Done, transportFactory TransportFactory) *Manager
  • func (m *Manager) Offer(ctx context.Context, target, headerValue string, arg interface{}, ...) bool
• type ProbeOption
• type TransportFactory

Functions

func Do

func Do(ctx context.Context, transport http.RoundTripper, target, headerValue string, pos ...ProbeOption) (bool, error)

Do sends a single probe to given target, e.g. `http://revision.default.svc.cluster.local:81`. headerValue is the value for the `k-network-probe` header. Do returns whether the probe was successful or not, or there was an error probing.

Types

type Done

type Done func(arg interface{}, success bool, err error)

Done is a callback that is executed when the async probe has finished. `arg` is given by the caller at the offering time, while `success` and `err` are the return values of the `Do` call. It is assumed that the opaque arg is consistent for a given target and we will coalesce concurrent Offer invocations on target.

type Manager

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

Manager manages async probes and makes sure we run concurrently only a single probe for the same key.

func New

func New(cb Done, transportFactory TransportFactory) *Manager

New creates a new Manager, that will invoke the given callback when async probing is finished.

func (*Manager) Offer

func (m *Manager) Offer(ctx context.Context, target, headerValue string, arg interface{}, period, timeout time.Duration) bool

Offer executes asynchronous probe using `target` as the key. If a probe with the same key already exists, Offer will return false and the call is discarded. If the request is accepted, Offer returns true. Otherwise Offer starts a goroutine that periodically executes `Do`, until timeout is reached, the probe succeeds, or fails with an error. In the end the callback is invoked with the provided `arg` and probing results.

type ProbeOption

type ProbeOption func(r *http.Request) *http.Request

ProbeOption is a way for caller to modify the HTTP request before it goes out.

type TransportFactory

type TransportFactory func() http.RoundTripper

TransportFactory is a function which returns an HTTP transport.