VictoriaMetrics/app/vmselect/prometheus/federate.qtpl

{% import (
	"math"

	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/netstorage"
) %}

{% stripspace %}

// Federate writes rs in /federate format.
// See https://prometheus.io/docs/prometheus/latest/federation/
{% func Federate(rs *netstorage.Result) %}
	{% code
		values := rs.Values
		timestamps := rs.Timestamps
	%}
	{% if len(timestamps) == 0 || len(values) == 0 %}{% return %}{% endif %}
	{% code
		lastValue := values[len(values)-1]
	%}
	{% if math.IsNaN(lastValue) %}
		{% comment %}
			This is most likely a staleness marker.
			Return nothing after the staleness marker.
			See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3185
		{% endcomment %}
		{% return %}
	{% endif %}
	{%= prometheusMetricName(&rs.MetricName) %}{% space %}
	{%f= lastValue %}{% space %}
	{%dl= timestamps[len(timestamps)-1] %}{% newline %}
{% endfunc %}

{% endstripspace %}