Function ExampleGaugeFunc_constLabels

prometheus/examples_test.go:94–130

()

}

func ExampleGaugeFunc_constLabels() {
	// primaryDB and secondaryDB represent two example *sql.DB connections we want to instrument.
	var primaryDB, secondaryDB interface {
		Stats() struct{ OpenConnections int }
	}

	if err := prometheus.Register(prometheus.NewGaugeFunc(
		prometheus.GaugeOpts{
			Namespace:   "mysql",
			Name:        "connections_open",
			Help:        "Number of mysql connections open.",
			ConstLabels: prometheus.Labels{"destination": "primary"},
		},
		func() float64 { return float64(primaryDB.Stats().OpenConnections) },
	)); err == nil {
		fmt.Println(`GaugeFunc 'connections_open' for primary DB connection registered with labels {destination="primary"}`)
	}

	if err := prometheus.Register(prometheus.NewGaugeFunc(
		prometheus.GaugeOpts{
			Namespace:   "mysql",
			Name:        "connections_open",
			Help:        "Number of mysql connections open.",
			ConstLabels: prometheus.Labels{"destination": "secondary"},
		},
		func() float64 { return float64(secondaryDB.Stats().OpenConnections) },
	)); err == nil {
		fmt.Println(`GaugeFunc 'connections_open' for secondary DB connection registered with labels {destination="secondary"}`)
	}

	// Note that we can register more than once GaugeFunc with same metric name
	// as long as their const labels are consistent.

	// Output:
	// GaugeFunc 'connections_open' for primary DB connection registered with labels {destination="primary"}
	// GaugeFunc 'connections_open' for secondary DB connection registered with labels {destination="secondary"}
}

func ExampleCounterVec() {
	httpReqs := prometheus.NewCounterVec(