From f7a3a23d30d64c57aa43fd1e1b89424a750bb0dd Mon Sep 17 00:00:00 2001
From: Etienne Perot <eperot@google.com>
Date: Tue, 21 Feb 2023 14:25:56 -0800
Subject: [PATCH] Export metric server metrics.

PiperOrigin-RevId: 511305940
---
 runsc/cmd/metric_server.go | 38 +++++++++++++++++++++++++-------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/runsc/cmd/metric_server.go b/runsc/cmd/metric_server.go
index 92121ce18..57932a66a 100644
--- a/runsc/cmd/metric_server.go
+++ b/runsc/cmd/metric_server.go
@@ -463,48 +463,60 @@ func (m *MetricServer) serveIndex(w http.ResponseWriter, req *http.Request) http
 
 // Metrics generated by the metrics server itself.
 var (
-	sandboxPresenceMetric = prometheus.Metric{
+	SandboxPresenceMetric = prometheus.Metric{
 		Name: "sandbox_presence",
 		Type: prometheus.TypeGauge,
 		Help: "Boolean metric set to 1 for each known sandbox.",
 	}
-	sandboxRunningMetric = prometheus.Metric{
+	SandboxRunningMetric = prometheus.Metric{
 		Name: "sandbox_running",
 		Type: prometheus.TypeGauge,
 		Help: "Boolean metric set to 1 for each running sandbox.",
 	}
-	sandboxMetadataMetric = prometheus.Metric{
+	SandboxMetadataMetric = prometheus.Metric{
 		Name: "sandbox_metadata",
 		Type: prometheus.TypeGauge,
 		Help: "Key-value pairs about per-sandbox metadata.",
 	}
-	sandboxCreationMetric = prometheus.Metric{
+	SandboxCreationMetric = prometheus.Metric{
 		Name: "sandbox_creation_time_seconds",
 		Type: prometheus.TypeGauge,
 		Help: "When the sandbox was created, as a unix timestamp in milliseconds.",
 	}
-	numRunningSandboxesMetric = prometheus.Metric{
+	NumRunningSandboxesMetric = prometheus.Metric{
 		Name: "num_sandboxes_running",
 		Type: prometheus.TypeGauge,
 		Help: "Number of sandboxes running at present.",
 	}
-	numCannotExportSandboxesMetric = prometheus.Metric{
+	NumCannotExportSandboxesMetric = prometheus.Metric{
 		Name: "num_sandboxes_broken_metrics",
 		Type: prometheus.TypeGauge,
 		Help: "Number of sandboxes from which we cannot export metrics.",
 	}
-	numTotalSandboxesMetric = prometheus.Metric{
+	NumTotalSandboxesMetric = prometheus.Metric{
 		Name: "num_sandboxes_total",
 		Type: prometheus.TypeCounter,
 		Help: "Counter of sandboxes that have ever been started.",
 	}
-	processStartTimeMetric = prometheus.Metric{
+	ProcessStartTimeMetric = prometheus.Metric{
 		Name: "process_start_time_seconds",
 		Type: prometheus.TypeGauge,
 		Help: "Unix timestamp at which the process started. Used by Prometheus for counter resets.",
 	}
 )
 
+// ServerMetrics is a list of metrics that the metric server generates.
+var ServerMetrics = []prometheus.Metric{
+	SandboxPresenceMetric,
+	SandboxRunningMetric,
+	SandboxMetadataMetric,
+	SandboxCreationMetric,
+	NumRunningSandboxesMetric,
+	NumCannotExportSandboxesMetric,
+	NumTotalSandboxesMetric,
+	ProcessStartTimeMetric,
+}
+
 // serveMetrics serves metrics requests.
 func (m *MetricServer) serveMetrics(w http.ResponseWriter, req *http.Request) httpResult {
 	ctx, ctxCancel := context.WithTimeout(req.Context(), metricsExportTimeout)
@@ -616,16 +628,16 @@ func (m *MetricServer) serveMetrics(w http.ResponseWriter, req *http.Request) ht
 				func() {
 					metricsMu.Lock()
 					defer metricsMu.Unlock()
-					selfMetrics.Add(prometheus.LabeledIntData(&sandboxPresenceMetric, served.extraLabels, 1))
+					selfMetrics.Add(prometheus.LabeledIntData(&SandboxPresenceMetric, served.extraLabels, 1))
 					sandboxRunning := int64(0)
 					if isRunning {
 						sandboxRunning = 1
 						meta.numRunningSandboxes++
 					}
-					selfMetrics.Add(prometheus.LabeledIntData(&sandboxRunningMetric, served.extraLabels, sandboxRunning))
+					selfMetrics.Add(prometheus.LabeledIntData(&SandboxRunningMetric, served.extraLabels, sandboxRunning))
 					if loadErr == nil {
-						selfMetrics.Add(prometheus.LabeledIntData(&sandboxMetadataMetric, served.labelsWithMetadata, 1))
-						selfMetrics.Add(prometheus.LabeledFloatData(&sandboxCreationMetric, served.extraLabels, float64(served.createdAt.Unix())+(float64(served.createdAt.Nanosecond())/1e9)))
+						selfMetrics.Add(prometheus.LabeledIntData(&SandboxMetadataMetric, served.labelsWithMetadata, 1))
+						selfMetrics.Add(prometheus.LabeledFloatData(&SandboxCreationMetric, served.extraLabels, float64(served.createdAt.Unix())+(float64(served.createdAt.Nanosecond())/1e9)))
 					}
 					if sandboxErr != nil {
 						// If the sandbox isn't running, it is normal that metrics are not exported for it, so
@@ -659,7 +671,7 @@ func (m *MetricServer) serveMetrics(w http.ResponseWriter, req *http.Request) ht
 		ExporterPrefix: fmt.Sprintf("%smeta_", m.exporterPrefix),
 	}
 	processMetrics := prometheus.NewSnapshot()
-	processMetrics.Add(prometheus.NewFloatData(&processStartTimeMetric, float64(m.startTime.Unix())+(float64(m.startTime.Nanosecond())/1e9)))
+	processMetrics.Add(prometheus.NewFloatData(&ProcessStartTimeMetric, float64(m.startTime.Unix())+(float64(m.startTime.Nanosecond())/1e9)))
 	snapshotsToOptions[processMetrics] = prometheus.SnapshotExportOptions{
 		// These metrics must be written without any prefix.
 	}