metrics.go

package main

import (
	"net/http"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	log "github.com/sirupsen/logrus"
)

var metrics = struct {
	lastSyncTimestamp              prometheus.Gauge
	ingressesTotal                 prometheus.Gauge
	routegroupsTotal               prometheus.Gauge
	stacksTotal                    prometheus.Gauge
	ownedAutoscalingGroupsTotal    prometheus.Gauge
	targetedAutoscalingGroupsTotal prometheus.Gauge
	instancesTotal                 prometheus.Gauge
	standaloneInstancesTotal       prometheus.Gauge
	certificatesTotal              prometheus.Gauge
	cloudWatchAlarmsTotal          prometheus.Gauge
	changesTotal                   changeCounter
}{
	lastSyncTimestamp: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "last_sync_timestamp_seconds",
			Help:      "Timestamp of the last successful controller reconciliation run",
		},
	),
	ingressesTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "ingresses_total",
			Help:      "Number of managed Kubernetes Ingresses",
		},
	),
	routegroupsTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "routegroups_total",
			Help:      "Number of managed Route Groups",
		},
	),
	stacksTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "stacks_total",
			Help:      "Number of managed Cloud Formation stacks",
		},
	),
	ownedAutoscalingGroupsTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "owned_autoscaling_groups_total",
			Help:      "Number of owned Autoscaling Groups",
		},
	),
	targetedAutoscalingGroupsTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "targeted_autoscaling_groups_total",
			Help:      "Number of targeted Autoscaling Groups",
		},
	),
	instancesTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "instances_total",
			Help:      "Number of managed EC2 instances",
		},
	),
	standaloneInstancesTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "standalone_instances_total",
			Help:      "Number of managed EC2 instances not in the Autoscaling Group",
		},
	),
	certificatesTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "certificates_total",
			Help:      "Number of certificates",
		},
	),
	cloudWatchAlarmsTotal: prometheus.NewGauge(
		prometheus.GaugeOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "cloud_watch_alarms_total",
			Help:      "Number of Cloud Watch Alarms",
		},
	),
	changesTotal: changeCounter{prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Namespace: "kube_ingress_aws",
			Subsystem: "controller",
			Name:      "changes_total",
			Help:      "Number of Cloud Formation stack, Kubernetes Ingress and Route Group changes",
		},
		[]string{"resource_type", "operation"},
	)},
}

type changeCounter struct {
	*prometheus.CounterVec
}

func (c changeCounter) created(resourceType string) {
	c.WithLabelValues(resourceType, "create").Inc()
}

func (c changeCounter) updated(resourceType string) {
	c.WithLabelValues(resourceType, "update").Inc()
}

func (c changeCounter) deleted(resourceType string) {
	c.WithLabelValues(resourceType, "delete").Inc()
}

func registerMetrics() {
	prometheus.MustRegister(metrics.lastSyncTimestamp)
	prometheus.MustRegister(metrics.ingressesTotal)
	prometheus.MustRegister(metrics.routegroupsTotal)
	prometheus.MustRegister(metrics.stacksTotal)
	prometheus.MustRegister(metrics.ownedAutoscalingGroupsTotal)
	prometheus.MustRegister(metrics.targetedAutoscalingGroupsTotal)
	prometheus.MustRegister(metrics.instancesTotal)
	prometheus.MustRegister(metrics.standaloneInstancesTotal)
	prometheus.MustRegister(metrics.certificatesTotal)
	prometheus.MustRegister(metrics.cloudWatchAlarmsTotal)
	prometheus.MustRegister(metrics.changesTotal)
}

func serveMetrics(address string) {
	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(address, nil))
}