From eb5ef4bc8341162eb53e80d1c464c45132783457 Mon Sep 17 00:00:00 2001
From: Guo Peng <370090914@qq.com>
Date: Fri, 8 Dec 2023 23:40:24 +0800
Subject: [PATCH] feat: add metrics to show target size of every node group

---
 cluster-autoscaler/clusterstate/clusterstate.go |  1 +
 cluster-autoscaler/metrics/metrics.go           | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/cluster-autoscaler/clusterstate/clusterstate.go b/cluster-autoscaler/clusterstate/clusterstate.go
index 57444a6536e6..202ec8765d2c 100644
--- a/cluster-autoscaler/clusterstate/clusterstate.go
+++ b/cluster-autoscaler/clusterstate/clusterstate.go
@@ -319,6 +319,7 @@ func (csr *ClusterStateRegistry) UpdateNodes(nodes []*apiv1.Node, nodeInfosForGr
 	if err != nil {
 		return err
 	}
+	metrics.UpdateNodeGroupTargetSize(targetSizes)
 
 	cloudProviderNodeInstances, err := csr.getCloudProviderNodeInstances()
 	if err != nil {
diff --git a/cluster-autoscaler/metrics/metrics.go b/cluster-autoscaler/metrics/metrics.go
index dfa1d4f7daa7..d7d8246ef9e1 100644
--- a/cluster-autoscaler/metrics/metrics.go
+++ b/cluster-autoscaler/metrics/metrics.go
@@ -200,6 +200,14 @@ var (
 		}, []string{"node_group"},
 	)
 
+	nodesGroupTargetSize = k8smetrics.NewGaugeVec(
+		&k8smetrics.GaugeOpts{
+			Namespace: caNamespace,
+			Name:      "node_group_target_count",
+			Help:      "Target number of nodes in the node group by CA.",
+		}, []string{"node_group"},
+	)
+
 	/**** Metrics related to autoscaler execution ****/
 	lastActivity = k8smetrics.NewGaugeVec(
 		&k8smetrics.GaugeOpts{
@@ -422,6 +430,7 @@ func RegisterAll(emitPerNodeGroupMetrics bool) {
 	if emitPerNodeGroupMetrics {
 		legacyregistry.MustRegister(nodesGroupMinNodes)
 		legacyregistry.MustRegister(nodesGroupMaxNodes)
+		legacyregistry.MustRegister(nodesGroupTargetSize)
 	}
 }
 
@@ -520,6 +529,13 @@ func UpdateNodeGroupMax(nodeGroup string, maxNodes int) {
 	nodesGroupMaxNodes.WithLabelValues(nodeGroup).Set(float64(maxNodes))
 }
 
+// UpdateNodeGroupTargetSize records the node group target size
+func UpdateNodeGroupTargetSize(targetSizes map[string]int) {
+	for nodeGroup, targetSize := range targetSizes {
+		nodesGroupTargetSize.WithLabelValues(nodeGroup).Set(float64(targetSize))
+	}
+}
+
 // RegisterError records any errors preventing Cluster Autoscaler from working.
 // No more than one error should be recorded per loop.
 func RegisterError(err errors.AutoscalerError) {