metrics.go

// SPDX-FileCopyrightText: 2022 Comcast Cable Communications Management, LLC
// SPDX-License-Identifier: Apache-2.0

package ancla

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/xmidt-org/argus/chrysom"
	"github.com/xmidt-org/touchstone"
	"go.uber.org/fx"
	"go.uber.org/multierr"
)

// Names
const (
	WebhookListSizeGaugeName     = "webhook_list_size"
	WebhookListSizeGaugeHelp     = "Size of the current list of webhooks."
	ChrysomPollsTotalCounterName = chrysom.PollCounter
	ChrysomPollsTotalCounterHelp = "Counter for the number of polls (and their success/failure outcomes) to fetch new items."
)

// Labels
const (
	OutcomeLabel = "outcome"
)

// Outcomes
const (
	SuccessOutcome = "success"
	FailureOutcome = "failure"
)

// Measures describes the defined metrics that will be used by clients.
type Measures struct {
	WebhookListSizeGaugeName     prometheus.Gauge       `name:"webhook_list_size"`
	ChrysomPollsTotalCounterName *prometheus.CounterVec `name:"chrysom_polls_total"`
}

type MeasuresOut struct {
	fx.Out

	M *Measures
}

// MeasuresIn is an uber/fx parameter with the webhook registration counter.
type MeasuresIn struct {
	fx.In

	Factory *touchstone.Factory `optional:"true"`
}

// NewMeasures realizes desired metrics.
func NewMeasures(in MeasuresIn) (MeasuresOut, error) {
	var metricErr error
	wlm, err := in.Factory.NewGauge(
		prometheus.GaugeOpts{
			Name: WebhookListSizeGaugeName,
			Help: WebhookListSizeGaugeHelp,
		},
	)
	err = multierr.Append(err, metricErr)
	cpm, err2 := in.Factory.NewCounterVec(
		prometheus.CounterOpts{
			Name: ChrysomPollsTotalCounterName,
			Help: ChrysomPollsTotalCounterHelp,
		},
		OutcomeLabel,
	)
	err = multierr.Append(err, err2)

	return MeasuresOut{
		M: &Measures{
			WebhookListSizeGaugeName:     wlm,
			ChrysomPollsTotalCounterName: cpm,
		},
	}, multierr.Append(err, metricErr)
}

// ProvideMetrics provides the metrics relevant to this package as uber/fx options.
func ProvideMetrics() fx.Option {
	return fx.Options(
		fx.Provide(NewMeasures),
	)
}