Implement container_processes metric

gavinkflam · gavinkflam · commit 2ed6ccac7e0c · 2025-07-31T00:00:40.000-04:00
Signed-off-by: Gavin Lam &lt;gavin.oss@tutamail.com&gt;
diff --git a/internal/lib/stats/descriptors.go b/internal/lib/stats/descriptors.go
@@ -163,3 +163,12 @@ var (
 		LabelKeys: baseLabelKeys,
 	}
 )
+
+// Process metrics.
+var (
+	containerProcesses = &types.MetricDescriptor{
+		Name:      "container_processes",
+		Help:      "Number of processes running inside the container",
+		LabelKeys: baseLabelKeys,
+	}
+)
diff --git a/internal/lib/stats/metrics.go b/internal/lib/stats/metrics.go
@@ -16,6 +16,7 @@ const (
 	MemoryMetrics  = "memory"
 	NetworkMetrics = "network"
 	OOMMetrics     = "oom"
+	ProcessMetrics = "process"
 )
 
 type metricValue struct {
@@ -90,6 +91,9 @@ func (ss *StatsServer) PopulateMetricDescriptors(includedKeys []string) map[stri
 		OOMMetrics: {
 			containerOomEventsTotal,
 		},
+		ProcessMetrics: {
+			containerProcesses,
+		},
 	}
 
 	return descriptorsMap
diff --git a/internal/lib/stats/process_metrics.go b/internal/lib/stats/process_metrics.go
@@ -0,0 +1,24 @@
+package statsserver
+
+import (
+	types "k8s.io/cri-api/pkg/apis/runtime/v1"
+
+	"github.com/cri-o/cri-o/internal/config/cgmgr"
+	"github.com/cri-o/cri-o/internal/lib/sandbox"
+)
+
+func generateSandboxProcessMetrics(sb *sandbox.Sandbox, pids *cgmgr.PidsStats) []*types.Metric {
+	processMetrics := []*containerMetric{
+		{
+			desc: containerProcesses,
+			valueFunc: func() metricValues {
+				return metricValues{{
+					value:      pids.Current,
+					metricType: types.MetricType_GAUGE,
+				}}
+			},
+		},
+	}
+
+	return computeSandboxMetrics(sb, processMetrics, "process")
+}
diff --git a/internal/lib/stats/stats_server_linux.go b/internal/lib/stats/stats_server_linux.go
@@ -267,6 +267,10 @@ func (ss *StatsServer) containerMetricsFromCgStats(sb *sandbox.Sandbox, c *oci.C
 			metrics = append(metrics, oomMetrics...)
 		case NetworkMetrics:
 			continue // Network metrics are collected at the pod level only.
+		case ProcessMetrics:
+			if processMetrics := generateSandboxProcessMetrics(sb, cgstats.Pid); processMetrics != nil {
+				metrics = append(metrics, processMetrics...)
+			}
 		default:
 			log.Warnf(ss.ctx, "Unknown metric: %s", m)
 		}
diff --git a/test/cri-metrics.bats b/test/cri-metrics.bats
@@ -169,10 +169,8 @@ EOF
 collection_period = 0
 included_pod_metrics = [
     "network",
-    "cpu",
     "hugetlb",
     "memory",
-    "oom",
 ]
 EOF
 	start_crio_no_setup
@@ -230,3 +228,31 @@ EOF
 		echo 0 | tee /proc/sys/vm/nr_hugepages
 	fi
 }
+
+@test "container process metrics" {
+	CONTAINER_ENABLE_METRICS="true" CONTAINER_METRICS_PORT=$(free_port) setup_crio
+	cat << EOF > "$CRIO_CONFIG"
+[crio.stats]
+collection_period = 0
+included_pod_metrics = [
+    "network",
+    "memory",
+    "process",
+]
+EOF
+	start_crio_no_setup
+	check_images
+
+	metrics_setup
+	set_container_pod_cgroup_root "" "$CONTAINER_ID"
+
+	# run some processes in the container
+	crictl exec --sync "$CONTAINER_ID" /bin/bash -c 'sleep 30 &'
+	crictl exec --sync "$CONTAINER_ID" /bin/bash -c 'sleep 30 &'
+
+	metrics=$(crictl metricsp | jq '.podMetrics[0].containerMetrics[0].metrics[]')
+
+	# assert container_processes == 3
+	metrics_container_processes=$(echo "$metrics" | jq 'select(.name == "container_processes") | .value.value | tonumber')
+	[[ $metrics_container_processes == "3" ]]
+}

Original file line number	Diff line number	Diff line change
`@@ -163,3 +163,12 @@ var (`
`163`	`163`	`LabelKeys: baseLabelKeys,`
`164`	`164`	`}`
`165`	`165`	`)`
	`166`	`+`
	`167`	`+// Process metrics.`
	`168`	`+var (`
	`169`	`+ containerProcesses = &types.MetricDescriptor{`
	`170`	`+ Name: "container_processes",`
	`171`	`+ Help: "Number of processes running inside the container",`
	`172`	`+ LabelKeys: baseLabelKeys,`
	`173`	`+ }`
	`174`	`+)`