prober

Documentation

Overview

Package prober implements a simple blackbox prober. Each probe runs in its own goroutine, and run results are recorded as Prometheus metrics.

Index

• func DERP(p *Prober, derpMapURL string, ...) (*derpProber, error)
• func SendAlert(summary, details string) error
• func SendWarning(details string) error
• type Probe
  • func (p *Probe) Close() error
• type ProbeFunc
  • func HTTP(url, wantText string) ProbeFunc
  • func TCP(addr string) ProbeFunc
  • func TLS(hostname string) ProbeFunc
• type Prober
  • func New() *Prober
  • func (p *Prober) Expvar() expvar.Var
  • func (p *Prober) Run(name string, interval time.Duration, labels map[string]string, fun ProbeFunc) *Probe
  • func (p *Prober) WithSpread(s bool) *Prober

Functions

func DERP

func DERP(p *Prober, derpMapURL string, udpInterval, meshInterval, tlsInterval time.Duration) (*derpProber, error)

DERP creates a new derpProber.

func SendAlert

func SendAlert(summary, details string) error

SendAlert sends an alert to the incident response system, to page a human responder immediately. summary should be short and state the nature of the emergency. details can be longer, up to 29 KBytes.

func SendWarning

func SendWarning(details string) error

SendWarning will post a message to Slack. details should be a description of the issue.

Types

type Probe

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

Probe is a probe that healthchecks something and updates Prometheus metrics with the results.

func (*Probe) Close

func (p *Probe) Close() error

Close shuts down the Probe and unregisters it from its Prober. It is safe to Run a new probe of the same name after Close returns.

type ProbeFunc

type ProbeFunc func(context.Context) error

ProbeFunc is a function that probes something and reports whether the probe succeeded. The provided context's deadline must be obeyed for correct probe scheduling.

func HTTP

func HTTP(url, wantText string) ProbeFunc

HTTP returns a Probe that healthchecks an HTTP URL.

The ProbeFunc sends a GET request for url, expects an HTTP 200 response, and verifies that want is present in the response body.

func TCP

func TCP(addr string) ProbeFunc

TCP returns a Probe that healthchecks a TCP endpoint.

The ProbeFunc reports whether it can successfully connect to addr.

func TLS

func TLS(hostname string) ProbeFunc

TLS returns a Probe that healthchecks a TLS endpoint.

The ProbeFunc connects to a hostname (host:port string), does a TLS handshake, verifies that the hostname matches the presented certificate, checks certificate validity time and OCSP revocation status.

type Prober

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

a Prober manages a set of probes and keeps track of their results.

func New

func New() *Prober

New returns a new Prober.

func (*Prober) Expvar

func (p *Prober) Expvar() expvar.Var

Expvar returns the metrics for running probes.

func (*Prober) Run

func (p *Prober) Run(name string, interval time.Duration, labels map[string]string, fun ProbeFunc) *Probe

Run executes fun every interval, and exports probe results under probeName.

Registering a probe under an already-registered name panics.

func (*Prober) WithSpread

func (p *Prober) WithSpread(s bool) *Prober

WithSpread is used to enable random delay before the first run of each added probe.