metrics

Documentation

Overview

Package metrics contains expvar & Prometheus types and code used by Tailscale for monitoring.

Index

• type LabelMap
  • func (m *LabelMap) Get(key string) *expvar.Int
  • func (m *LabelMap) GetFloat(key string) *expvar.Float
• type Set

Types

type LabelMap

type LabelMap struct {
	Label string
	expvar.Map
}

LabelMap is a string-to-Var map variable that satisfies the expvar.Var interface.

Semantically, this is mapped by tsweb's Prometheus exporter as a collection of variables with the same name, with a varying label value. Use this to export things that are intuitively breakdowns into different buckets.

func (*LabelMap) Get

func (m *LabelMap) Get(key string) *expvar.Int

Get returns a direct pointer to the expvar.Int for key, creating it if necessary.

func (*LabelMap) GetFloat

func (m *LabelMap) GetFloat(key string) *expvar.Float

GetFloat returns a direct pointer to the expvar.Float for key, creating it if necessary.

type Set

type Set struct {
	expvar.Map
}

Set is a string-to-Var map variable that satisfies the expvar.Var interface.

Semantically, this is mapped by tsweb's Prometheus exporter as a collection of unrelated variables exported with a common prefix.

This lets us have tsweb recognize *expvar.Map for different purposes in the future. (Or perhaps all uses of expvar.Map will require explicit types like this one, declaring how we want tsweb to export it to Prometheus.)