Refactor controller metrics interface

internal/ingress/metric/collectors/controller.go

@@ -0,0 +1,218 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package collectors
+
+import (
+	"time"
+
+	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/ingress-nginx/internal/ingress"
+)
+
+var (
+	operation    = []string{"namespace", "class"}
+	sslLabelHost = []string{"namespace", "class", "host"}
+)
+
+// Controller defines base metrics about the ingress controller
+type Controller struct {
+	prometheus.Collector
+
+	configHash        prometheus.Gauge
+	configSuccess     prometheus.Gauge
+	configSuccessTime prometheus.Gauge
+
+	reloadOperation       *prometheus.CounterVec
+	reloadOperationErrors *prometheus.CounterVec
+	sslExpireTime         *prometheus.GaugeVec
+
+	labels prometheus.Labels
+}
+
+// NewController creates a new prometheus collector for the
+// Ingress controller operations
+func NewController(pod, namespace, class string) *Controller {
+	constLabels := prometheus.Labels{
+		"controller_namespace": namespace,
+		"controller_class":     class,
+		"controller_pod":       pod,
+	}
+
+	cm := &Controller{
+		labels: prometheus.Labels{
+			"namespace": namespace,
+			"class":     class,
+		},
+
+		configHash: prometheus.NewGauge(
+			prometheus.GaugeOpts{
+				Namespace:   PrometheusNamespace,
+				Name:        "config_hash",
+				Help:        "Running configuration hash actually running",
+				ConstLabels: constLabels,
+			},
+		),
+		configSuccess: prometheus.NewGauge(
+			prometheus.GaugeOpts{
+				Namespace:   PrometheusNamespace,
+				Name:        "config_last_reload_successful",
+				Help:        "Whether the last configuration reload attemp was successful",
+				ConstLabels: constLabels,
+			}),
+		configSuccessTime: prometheus.NewGauge(
+			prometheus.GaugeOpts{
+				Namespace:   PrometheusNamespace,
+				Name:        "config_last_reload_successful_timestamp_seconds",
+				Help:        "Timestamp of the last successful configuration reload.",
+				ConstLabels: constLabels,
+			}),
+		reloadOperation: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Namespace: PrometheusNamespace,
+				Name:      "success",
+				Help:      `Cumulative number of Ingress controller reload operations`,
+			},
+			operation,
+		),
+		reloadOperationErrors: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Namespace: PrometheusNamespace,
+				Name:      "errors",
+				Help:      `Cumulative number of Ingress controller errors during reload operations`,
+			},
+			operation,
+		),
+		sslExpireTime: prometheus.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Namespace: PrometheusNamespace,
+				Name:      "ssl_expire_time_seconds",
+				Help: `Number of seconds since 1970 to the SSL Certificate expire.
+			An example to check if this certificate will expire in 10 days is: "nginx_ingress_controller_ssl_expire_time_seconds < (time() + (10 * 24 * 3600))"`,
+			},
+			sslLabelHost,
+		),
+	}
+
+	return cm
+}
+
+// IncReloadCount increment the reload counter
+func (cm *Controller) IncReloadCount() {
+	cm.reloadOperation.With(cm.labels).Inc()
+}
+
+// IncReloadErrorCount increment the reload error counter
+func (cm *Controller) IncReloadErrorCount() {
+	cm.reloadOperationErrors.With(cm.labels).Inc()
+}
+
+// ConfigSuccess set a boolean flag according to the output of the controller configuration reload
+func (cm *Controller) ConfigSuccess(hash uint64, success bool) {
+	if success {
+		cm.configSuccessTime.Set(float64(time.Now().Unix()))
+		cm.configSuccess.Set(1)
+
+		cm.configHash.Set(float64(hash))
+
+		return
+	}
+
+	cm.configSuccess.Set(0)
+	cm.configHash.Set(0)
+}
+
+// Describe implements prometheus.Collector
+func (cm Controller) Describe(ch chan<- *prometheus.Desc) {
+	cm.configHash.Describe(ch)
+	cm.configSuccess.Describe(ch)
+	cm.configSuccessTime.Describe(ch)
+	cm.reloadOperation.Describe(ch)
+	cm.reloadOperationErrors.Describe(ch)
+	cm.sslExpireTime.Describe(ch)
+}
+
+// Collect implements the prometheus.Collector interface.
+func (cm Controller) Collect(ch chan<- prometheus.Metric) {
+	cm.configHash.Collect(ch)
+	cm.configSuccess.Collect(ch)
+	cm.configSuccessTime.Collect(ch)
+	cm.reloadOperation.Collect(ch)
+	cm.reloadOperationErrors.Collect(ch)
+	cm.sslExpireTime.Collect(ch)
+}
+
+// SetSSLExpireTime sets the expiration time of SSL Certificates
+func (cm *Controller) SetSSLExpireTime(servers []*ingress.Server) {
+	for _, s := range servers {
+		if s.Hostname != "" && s.SSLCert.ExpireTime.Unix() > 0 {
+			labels := make(prometheus.Labels, len(cm.labels)+1)
+			for k, v := range cm.labels {
+				labels[k] = v
+			}
+			labels["host"] = s.Hostname
+
+			cm.sslExpireTime.With(labels).Set(float64(s.SSLCert.ExpireTime.Unix()))
+		}
+	}
+}
+
+// RemoveMetrics removes metrics for hostames not available anymore
+func (cm *Controller) RemoveMetrics(hosts []string, registry prometheus.Gatherer) {
+	mfs, err := registry.Gather()
+	if err != nil {
+		glog.Errorf("Error gathering metrics: %v", err)
+		return
+	}
+
+	glog.V(2).Infof("removing SSL certificate metrics for %v hosts", hosts)
+	toRemove := sets.NewString(hosts...)
+
+	for _, mf := range mfs {
+		metricName := mf.GetName()
+		if "ssl_expire_time_seconds" != metricName {
+			continue
+		}
+
+		for _, m := range mf.GetMetric() {
+			labels := make(map[string]string, len(m.GetLabel()))
+			for _, labelPair := range m.GetLabel() {
+				labels[*labelPair.Name] = *labelPair.Value
+			}
+
+			// remove labels that are constant
+			deleteConstants(labels)
+
+			host, ok := labels["host"]
+			if !ok {
+				continue
+			}
+
+			if !toRemove.Has(host) {
+				continue
+			}
+
+			glog.V(2).Infof("Removing prometheus metric from gauge %v for host %v", metricName, host)
+			removed := cm.sslExpireTime.Delete(labels)
+			if !removed {
+				glog.V(2).Infof("metric %v for host %v with labels not removed: %v", metricName, host, labels)
+			}
+		}
+	}
+}