Function ExampleGatherers

prometheus/examples_test.go:575–686

()

}

func ExampleGatherers() {
	reg := prometheus.NewRegistry()
	temp := prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "temperature_kelvin",
			Help: "Temperature in Kelvin.",
		},
		[]string{"location"},
	)
	reg.MustRegister(temp)
	temp.WithLabelValues("outside").Set(273.14)
	temp.WithLabelValues("inside").Set(298.44)

	parser := expfmt.NewTextParser(model.UTF8Validation)

	text := `
# TYPE humidity_percent gauge
# HELP humidity_percent Humidity in %.
humidity_percent{location="outside"} 45.4
humidity_percent{location="inside"} 33.2
# TYPE temperature_kelvin gauge
# HELP temperature_kelvin Temperature in Kelvin.
temperature_kelvin{location="somewhere else"} 4.5
`

	parseText := func() ([]*dto.MetricFamily, error) {
		parsed, err := parser.TextToMetricFamilies(strings.NewReader(text))
		if err != nil {
			return nil, err
		}
		var result []*dto.MetricFamily
		for _, mf := range parsed {
			result = append(result, mf)
		}
		return result, nil
	}

	gatherers := prometheus.Gatherers{
		reg,
		prometheus.GathererFunc(parseText),
	}

	gathering, err := gatherers.Gather()
	if err != nil {
		fmt.Println(err)
	}

	out := &bytes.Buffer{}
	for _, mf := range gathering {
		if _, err := expfmt.MetricFamilyToText(out, mf); err != nil {
			panic(err)
		}
	}
	fmt.Print(out.String())
	fmt.Println("----------")

	// Note how the temperature_kelvin metric family has been merged from
	// different sources. Now try