Finalized new client golang abstraction and using it.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

Author: bwplotka

info/v2/container.go

@@ -270,7 +270,7 @@ type RequestOptions struct {
 	// Whether to include stats for child subcontainers.
 	Recursive bool `json:"recursive"`
 	// Update stats if they are older than MaxAge
-	// nil indicates no update, and 0 will always trigger an update.
+	// nil and 0 indicates always update.
 	MaxAge *time.Duration `json:"max_age"`
 }
 

metrics/prometheus.go

@@ -23,12 +23,26 @@ import (
 	"github.com/google/cadvisor/container"
 	info "github.com/google/cadvisor/info/v1"
 	v2 "github.com/google/cadvisor/info/v2"
+	dto "github.com/prometheus/client_model/go"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"k8s.io/klog/v2"
 	"k8s.io/utils/clock"
 )
 
+const (
+	// ContainerLabelPrefix is the prefix added to all container labels.
+	ContainerLabelPrefix = "container_label_"
+	// ContainerEnvPrefix is the prefix added to all env variable labels.
+	ContainerEnvPrefix = "container_env_"
+	// LabelID is the name of the id label.
+	LabelID = "id"
+	// LabelName is the name of the name label.
+	LabelName = "name"
+	// LabelImage is the name of the image label.
+	LabelImage = "image"
+)
+
 // asFloat64 converts a uint64 into a float64.
 func asFloat64(v uint64) float64 { return float64(v) }
 
@@ -83,45 +97,33 @@ type containerMetric struct {
 	getValues   func(s *info.ContainerStats) metricValues
 }
 
-func (cm *containerMetric) desc(session *prometheus.CollectSession, baseLabels []string) *prometheus.Desc {
-	if session == nil {
-		return prometheus.NewDesc(cm.name, cm.help, append(baseLabels, cm.extraLabels...), nil)
-	}
-	return session.NewDesc(cm.name, cm.help, append(baseLabels, cm.extraLabels...), nil)
-}
-
 // ContainerLabelsFunc defines all base labels and their values attached to
 // each metric exported by cAdvisor.
 type ContainerLabelsFunc func(*info.ContainerInfo) map[string]string
 
 // PrometheusCollector implements prometheus.Collector.
 type PrometheusCollector struct {
 	infoProvider        infoProvider
-	errors              prometheus.Gauge
 	containerMetrics    []containerMetric
 	containerLabelsFunc ContainerLabelsFunc
 	includedMetrics     container.MetricSet
 	opts                v2.RequestOptions
 
-	cache prometheus.CachedCollector
+	lastUpdate time.Time
+	cache *prometheus.CachedCollector
 }
 
 // NewPrometheusCollector returns a new PrometheusCollector. The passed
 // ContainerLabelsFunc specifies which base labels will be attached to all
 // exported metrics. If left to nil, the DefaultContainerLabels function
 // will be used instead.
-func NewPrometheusCollector(i infoProvider, f ContainerLabelsFunc, includedMetrics container.MetricSet, now clock.Clock, opts v2.RequestOptions) *PrometheusCollector {
+func NewPrometheusCollector(i infoProvider, f ContainerLabelsFunc, includedMetrics container.MetricSet, now clock.Clock) *PrometheusCollector {
 	if f == nil {
 		f = DefaultContainerLabels
 	}
 	c := &PrometheusCollector{
 		infoProvider:        i,
 		containerLabelsFunc: f,
-		errors: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "container",
-			Name:      "scrape_error",
-			Help:      "1 if there was an error while getting container metrics, 0 otherwise",
-		}),
 		containerMetrics: []containerMetric{
 			{
 				name:      "container_last_seen",
@@ -136,7 +138,7 @@ func NewPrometheusCollector(i infoProvider, f ContainerLabelsFunc, includedMetri
 			},
 		},
 		includedMetrics: includedMetrics,
-		opts:            opts,
+		cache: prometheus.NewCachedCollector(),
 	}
 	if includedMetrics.Has(container.CpuUsageMetrics) {
 		c.containerMetrics = append(c.containerMetrics, []containerMetric{
@@ -1776,51 +1778,53 @@ func NewPrometheusCollector(i infoProvider, f ContainerLabelsFunc, includedMetri
 	return c
 }
 
-var (
-	versionInfoDesc = prometheus.NewDesc("cadvisor_version_info", "A metric with a constant '1' value labeled by kernel version, OS version, docker version, cadvisor version & cadvisor revision.", []string{"kernelVersion", "osVersion", "dockerVersion", "cadvisorVersion", "cadvisorRevision"}, nil)
-	startTimeDesc   = prometheus.NewDesc("container_start_time_seconds", "Start time of the container since unix epoch in seconds.", nil, nil)
-	cpuPeriodDesc   = prometheus.NewDesc("container_spec_cpu_period", "CPU period of the container.", nil, nil)
-	cpuQuotaDesc    = prometheus.NewDesc("container_spec_cpu_quota", "CPU quota of the container.", nil, nil)
-	cpuSharesDesc   = prometheus.NewDesc("container_spec_cpu_shares", "CPU share of the container.", nil, nil)
-)
+func (c *PrometheusCollector) SetOpts(opts v2.RequestOptions) {
+	c.opts = opts
+}
+
+
+//// Describe describes all the metrics ever exported by cadvisor. It
+//// implements prometheus.PrometheusCollector.
+//func (c *PrometheusCollector) Describe(ch chan<- *prometheus.Desc) {
+//	panic("unpexected")
+//	//c.errors.Describe(ch)
+//	for _, cm := range c.containerMetrics {
+//		ch <- cm.desc(nil, []string{})
+//	}
+//}
+
+// Collect fetches latest statistics about containers and exposes them to Prometheus handler that converts them
+// to expected Prometheus format.
+// Based on option it
+// * ask the latest from provided services.
+// * returns cached results if until time expires.
+//
+// It implements prometheus.rawCollector.
+func (c *PrometheusCollector) Collect() []*dto.MetricFamily {
+	if c.opts.MaxAge == nil || time.Since(c.lastUpdate) > *c.opts.MaxAge {
+		c.lastUpdate = time.Now()
+		session := c.cache.NewSession()
+
+		errorsGauge := 0
+		if err := c.collectVersionInfo(session); err != nil {
+			errorsGauge = 1
+			klog.Warningf("Couldn't get version info: %s", err)
+		}
+		if err := c.collectContainersInfo(session); err != nil {
+			errorsGauge = 1
+			klog.Warningf("Couldn't get containers: %s", err)
+		}
 
-// Describe describes all the metrics ever exported by cadvisor. It
-// implements prometheus.PrometheusCollector.
-func (c *PrometheusCollector) Describe(ch chan<- *prometheus.Desc) {
-	c.errors.Describe(ch)
-	for _, cm := range c.containerMetrics {
-		ch <- cm.desc(nil, []string{})
+		session.MustAddMetric(
+			"container_scrape_error","1 if there was an error while getting container metrics, 0 otherwise",
+			nil, nil,prometheus.GaugeValue, float64(errorsGauge),nil,
+		)
+		session.Commit()
 	}
-	ch <- startTimeDesc
-	ch <- cpuPeriodDesc
-	ch <- cpuQuotaDesc
-	ch <- cpuSharesDesc
-	ch <- versionInfoDesc
-}
 
-// Collect fetches the stats from all containers and delivers them as
-// Prometheus metrics. It implements prometheus.PrometheusCollector.
-func (c *PrometheusCollector) Collect(ch chan<- prometheus.Metric) {
-	session := c.cache.NewSession()
-	c.errors.Set(0)
-	c.collectVersionInfo(session, ch)
-	c.collectContainersInfo(session, ch)
-	c.errors.Collect(ch)
+	return c.cache.Collect()
 }
 
-const (
-	// ContainerLabelPrefix is the prefix added to all container labels.
-	ContainerLabelPrefix = "container_label_"
-	// ContainerEnvPrefix is the prefix added to all env variable labels.
-	ContainerEnvPrefix = "container_env_"
-	// LabelID is the name of the id label.
-	LabelID = "id"
-	// LabelName is the name of the name label.
-	LabelName = "name"
-	// LabelImage is the name of the image label.
-	LabelImage = "image"
-)
-
 // DefaultContainerLabels implements ContainerLabelsFunc. It exports the
 // container name, first alias, image name as well as all its env and label
 // values.
@@ -1869,12 +1873,10 @@ func BaseContainerLabels(whiteList []string) func(container *info.ContainerInfo)
 	}
 }
 
-func (c *PrometheusCollector) collectContainersInfo(session *prometheus.CollectSession, ch chan<- prometheus.Metric) {
+func (c *PrometheusCollector) collectContainersInfo(session *prometheus.CollectSession) error {
 	containers, err := c.infoProvider.GetRequestedContainersInfo("/", c.opts)
 	if err != nil {
-		c.errors.Set(1)
-		klog.Warningf("Couldn't get containers: %s", err)
-		return
+		return err
 	}
 	rawLabels := map[string]struct{}{}
 	for _, container := range containers {
@@ -1903,30 +1905,43 @@ func (c *PrometheusCollector) collectContainersInfo(session *prometheus.CollectS
 		}
 
 		// Container spec.
-		desc := session.NewDesc("container_start_time_seconds", "Start time of the container since unix epoch in seconds.", labels, nil)
-		ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, float64(cont.Spec.CreationTime.Unix()), values...)
+		session.MustAddMetric(
+			"container_start_time_seconds","Start time of the container since unix epoch in seconds.",
+			labels, values,prometheus.GaugeValue, float64(cont.Spec.CreationTime.Unix()),nil,
+		)
 
 		if cont.Spec.HasCpu {
-			desc = session.NewDesc("container_spec_cpu_period", "CPU period of the container.", labels, nil)
-			ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, float64(cont.Spec.Cpu.Period), values...)
+			session.MustAddMetric(
+				"container_spec_cpu_period", "CPU period of the container.",
+				labels, values,prometheus.GaugeValue, float64(cont.Spec.Cpu.Period),nil,
+				 )
 			if cont.Spec.Cpu.Quota != 0 {
-				desc = session.NewDesc("container_spec_cpu_quota", "CPU quota of the container.", labels, nil)
-				ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, float64(cont.Spec.Cpu.Quota), values...)
+				session.MustAddMetric(
+					"container_spec_cpu_quota", "CPU quota of the container.",
+					labels, values,prometheus.GaugeValue, float64(cont.Spec.Cpu.Quota),nil,
+				)
 			}
-			desc := session.NewDesc("container_spec_cpu_shares", "CPU share of the container.", labels, nil)
-			ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, float64(cont.Spec.Cpu.Limit), values...)
-
+			session.MustAddMetric(
+				"container_spec_cpu_shares", "CPU share of the container.",
+				labels, values, prometheus.GaugeValue, float64(cont.Spec.Cpu.Limit),nil,
+			)
 		}
 		if cont.Spec.HasMemory {
-			desc := session.NewDesc("container_spec_memory_limit_bytes", "Memory limit for the container.", labels, nil)
-			ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, specMemoryValue(cont.Spec.Memory.Limit), values...)
-			desc = session.NewDesc("container_spec_memory_swap_limit_bytes", "Memory swap limit for the container.", labels, nil)
-			ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, specMemoryValue(cont.Spec.Memory.SwapLimit), values...)
-			desc = session.NewDesc("container_spec_memory_reservation_limit_bytes", "Memory reservation limit for the container.", labels, nil)
-			ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, specMemoryValue(cont.Spec.Memory.Reservation), values...)
+			session.MustAddMetric(
+				"container_spec_memory_limit_bytes", "Memory limit for the container.",
+				labels,values, prometheus.GaugeValue, specMemoryValue(cont.Spec.Memory.Limit),nil,
+		)
+			session.MustAddMetric(
+				"container_spec_memory_swap_limit_bytes", "Memory swap limit for the container.",
+				labels,values, prometheus.GaugeValue, specMemoryValue(cont.Spec.Memory.SwapLimit), nil,
+			)
+			session.MustAddMetric(
+				"container_spec_memory_reservation_limit_bytes", "Memory reservation limit for the container.",
+				labels, values, prometheus.GaugeValue, specMemoryValue(cont.Spec.Memory.Reservation), nil,
+			)
 		}
 
-		// Now for the actual metrics
+		// Now for the actual metrics.
 		if len(cont.Stats) == 0 {
 			continue
 		}
@@ -1935,11 +1950,11 @@ func (c *PrometheusCollector) collectContainersInfo(session *prometheus.CollectS
 			if cm.condition != nil && !cm.condition(cont.Spec) {
 				continue
 			}
-			desc := cm.desc(session, labels)
 			for _, metricValue := range cm.getValues(stats) {
-				ch <- prometheus.NewMetricWithTimestamp(
-					metricValue.timestamp,
-					prometheus.MustNewConstMetric(desc, cm.valueType, metricValue.value, append(values, metricValue.labels...)...),
+				session.MustAddMetric(
+					cm.name, cm.help,
+					append(labels, cm.extraLabels...), append(values, metricValue.labels...),
+					cm.valueType, metricValue.value, &metricValue.timestamp,
 				)
 			}
 		}
@@ -1954,22 +1969,30 @@ func (c *PrometheusCollector) collectContainersInfo(session *prometheus.CollectS
 						clabels = append(clabels, sanitizeLabelName("app_"+label))
 						cvalues = append(cvalues, value)
 					}
-					desc := session.NewDesc(metricLabel, "Custom application metric.", clabels, nil)
-					ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, metric.FloatValue, cvalues...)
+					session.MustAddMetric(
+						metricLabel, "Custom application metric.",
+						clabels,cvalues, prometheus.GaugeValue, metric.FloatValue, nil,
+					)
 				}
 			}
 		}
 	}
+	return nil
 }
 
-func (c *PrometheusCollector) collectVersionInfo(session *prometheus.CollectSession, ch chan<- prometheus.Metric) {
+func (c *PrometheusCollector) collectVersionInfo(session *prometheus.CollectSession) error {
 	versionInfo, err := c.infoProvider.GetVersionInfo()
 	if err != nil {
-		c.errors.Set(1)
-		klog.Warningf("Couldn't get version info: %s", err)
-		return
+		return err
 	}
-	ch <- prometheus.MustNewConstMetric(versionInfoDesc, prometheus.GaugeValue, 1, versionInfo.KernelVersion, versionInfo.ContainerOsVersion, versionInfo.DockerVersion, versionInfo.CadvisorVersion, versionInfo.CadvisorRevision)
+	session.MustAddMetric(
+		"cadvisor_version_info",
+		"A metric with a constant '1' value labeled by kernel version, OS version, docker version, cadvisor version & cadvisor revision.",
+		[]string{"kernelVersion", "osVersion", "dockerVersion", "cadvisorVersion", "cadvisorRevision"},
+		[]string{versionInfo.KernelVersion, versionInfo.ContainerOsVersion, versionInfo.DockerVersion, versionInfo.CadvisorVersion, versionInfo.CadvisorRevision},
+		prometheus.GaugeValue, 1, nil,
+	)
+	return nil
 }
 
 // Size after which we consider memory to be "unlimited". This is not

metrics/prometheus_bench_test.go

@@ -37,17 +37,21 @@ func BenchmarkPrometheusCollector_Collect(b *testing.B) {
 		infoProvider.containers[name] = genContainerInfo(name)
 	}
 
-	reg := prometheus.NewRegistry()
-	reg.MustRegister(NewPrometheusCollector(infoProvider, func(container *info.ContainerInfo) map[string]string {
+	reg := prometheus.NewBlockingRegistry()
+	c := NewPrometheusCollector(infoProvider, func(container *info.ContainerInfo) map[string]string {
 		s := DefaultContainerLabels(container)
 		s["zone.name"] = "hello"
 		return s
-	}, container.AllMetrics, now, v2.RequestOptions{}))
+	}, container.AllMetrics, now)
+	reg.MustRegisterRaw(c)
 
+	c.SetOpts(v2.RequestOptions{})
 	var err error
+	var done func()
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		mfsTmp, err = reg.Gather()
+		mfsTmp, done, err = reg.Gather()
 		require.NoError(b, err)
+		done()
 	}
 }