61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package metrics contains expvar & Prometheus types and code used by
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// Tailscale for monitoring.
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package metrics
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import "expvar"
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// Set is a string-to-Var map variable that satisfies the expvar.Var
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// interface.
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//
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// Semantically, this is mapped by tsweb's Prometheus exporter as a
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// collection of unrelated variables exported with a common prefix.
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//
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// This lets us have tsweb recognize *expvar.Map for different
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// purposes in the future. (Or perhaps all uses of expvar.Map will
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// require explicit types like this one, declaring how we want tsweb
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// to export it to Prometheus.)
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type Set struct {
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expvar.Map
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}
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// LabelMap is a string-to-Var map variable that satisfies the
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// expvar.Var interface.
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//
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// Semantically, this is mapped by tsweb's Prometheus exporter as a
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// collection of variables with the same name, with a varying label
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// value. Use this to export things that are intuitively breakdowns
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// into different buckets.
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type LabelMap struct {
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Label string
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expvar.Map
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}
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// SetInt64 sets the *Int value stored under the given map key.
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func (m *LabelMap) SetInt64(key string, v int64) {
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m.Get(key).Set(v)
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}
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// Get returns a direct pointer to the expvar.Int for key, creating it
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// if necessary.
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func (m *LabelMap) Get(key string) *expvar.Int {
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m.Add(key, 0)
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return m.Map.Get(key).(*expvar.Int)
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}
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// GetFloat returns a direct pointer to the expvar.Float for key, creating it
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// if necessary.
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func (m *LabelMap) GetFloat(key string) *expvar.Float {
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m.AddFloat(key, 0.0)
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return m.Map.Get(key).(*expvar.Float)
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}
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// CurrentFDs reports how many file descriptors are currently open.
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//
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// It only works on Linux. It returns zero otherwise.
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func CurrentFDs() int {
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return currentFDs()
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}
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