Stackdriver allows delegation of multiple projects to "main" one. This is very

useful to create inter-project dashbords, but also it delegates all metrics
to single project and could lead to big amounts of series. I've added optional
flag `monitoring.drop-delegated-projects` which allows one to disable collection
of these metrics. It's useful to split stackdriver-exporter instances per-project
and still be able to fetch metrics from main one.

Another option is to have empty main project only to delegate monitoring and
not to fetch metrics from.

Author: alexey-medvedchikov

collectors/monitoring_collector.go

@@ -28,6 +28,7 @@ type MonitoringCollector struct {
 	lastScrapeTimestampMetric       prometheus.Gauge
 	lastScrapeDurationSecondsMetric prometheus.Gauge
 	collectorFillMissingLabels      bool
+	monitoringDropDelegatedProjects bool
 }
 
 func NewMonitoringCollector(
@@ -37,6 +38,7 @@ func NewMonitoringCollector(
 	metricsOffset time.Duration,
 	monitoringService *monitoring.Service,
 	collectorFillMissingLabels bool,
+	monitoringDropDelegatedProjects bool,
 ) (*MonitoringCollector, error) {
 	apiCallsTotalMetric := prometheus.NewCounter(
 		prometheus.CounterOpts{
@@ -111,6 +113,7 @@ func NewMonitoringCollector(
 		lastScrapeTimestampMetric:       lastScrapeTimestampMetric,
 		lastScrapeDurationSecondsMetric: lastScrapeDurationSecondsMetric,
 		collectorFillMissingLabels:      collectorFillMissingLabels,
+		monitoringDropDelegatedProjects: monitoringDropDelegatedProjects,
 	}
 
 	return monitoringCollector, nil
@@ -271,6 +274,21 @@ func (c *MonitoringCollector) reportTimeSeriesMetrics(
 			labelValues = append(labelValues, value)
 		}
 
+		if c.monitoringDropDelegatedProjects {
+			dropDelegatedProject := false
+
+			for idx, val := range labelKeys {
+				if val == "project_id" && labelValues[idx] != c.projectID {
+					dropDelegatedProject = true
+					break
+				}
+			}
+
+			if dropDelegatedProject {
+				continue
+			}
+		}
+
 		switch timeSeries.MetricKind {
 		case "GAUGE":
 			metricValueType = prometheus.GaugeValue

stackdriver_exporter.go

@@ -23,6 +23,10 @@ var (
 		"google.project-id", "Google Project ID ($STACKDRIVER_EXPORTER_GOOGLE_PROJECT_ID).",
 	).Envar("STACKDRIVER_EXPORTER_GOOGLE_PROJECT_ID").Required().String()
 
+	monitoringDropDelegatedProjects = kingpin.Flag(
+		"monitoring.drop-delegated-projects", "Drop metrics from attached projects and fetch `project_id` only ($STACKDRIVER_EXPORTER_DROP_DELEGATED_PROJECTS).",
+	).Envar("STACKDRIVER_EXPORTER_DROP_DELEGATED_PROJECTS").Default("false").Bool()
+
 	monitoringMetricsTypePrefixes = kingpin.Flag(
 		"monitoring.metrics-type-prefixes", "Comma separated Google Stackdriver Monitoring Metric Type prefixes ($STACKDRIVER_EXPORTER_MONITORING_METRICS_TYPE_PREFIXES).",
 	).Envar("STACKDRIVER_EXPORTER_MONITORING_METRICS_TYPE_PREFIXES").Required().String()
@@ -124,7 +128,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	monitoringCollector, err := collectors.NewMonitoringCollector(*projectID, metricsTypePrefixes, *monitoringMetricsInterval, *monitoringMetricsOffset, monitoringService, *collectorFillMissingLabels)
+	monitoringCollector, err := collectors.NewMonitoringCollector(*projectID, metricsTypePrefixes, *monitoringMetricsInterval, *monitoringMetricsOffset, monitoringService, *collectorFillMissingLabels, *monitoringDropDelegatedProjects)
 	if err != nil {
 		log.Error(err)
 		os.Exit(1)