From 2f3d31a69a94000b4a5bf150a7d3c8b77500536d Mon Sep 17 00:00:00 2001
From: Rafael Mendez <mdzraf@amazon.com>
Date: Thu, 27 Feb 2025 19:41:39 +0000
Subject: [PATCH] Adding logs On How We Calculate CSINode.allocatables in
 NodeGetInfo

---
 pkg/cloud/metadata/ec2.go |  1 -
 pkg/driver/node.go        | 51 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/pkg/cloud/metadata/ec2.go b/pkg/cloud/metadata/ec2.go
index b0c39a6b48..0a7346d5db 100644
--- a/pkg/cloud/metadata/ec2.go
+++ b/pkg/cloud/metadata/ec2.go
@@ -90,7 +90,6 @@ func EC2MetadataInstanceInfo(svc EC2Metadata, regionFromSession string) (*Metada
 		return nil, fmt.Errorf("could not read ENIs metadata content: %w", err)
 	}
 	attachedENIs := util.CountMACAddresses(string(enis))
-	klog.V(4).InfoS("Number of attached ENIs", "attachedENIs", attachedENIs)
 
 	blockDevMappings := 0
 	if !util.IsSBE(doc.Region) {
diff --git a/pkg/driver/node.go b/pkg/driver/node.go
index ef7ae326d9..cc93188bf5 100644
--- a/pkg/driver/node.go
+++ b/pkg/driver/node.go
@@ -576,6 +576,56 @@ func (d *NodeService) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoReque
 	zone := d.metadata.GetAvailabilityZone()
 	osType := runtime.GOOS
 
+	if d.options.VolumeAttachLimit >= 0 {
+		klog.V(4).InfoS("NodeGetInfo: VolumeAttachLimit manually set to", d.options.VolumeAttachLimit, "overriding the default value")
+	} else {
+		instanceType := d.metadata.GetInstanceType()
+		isNitro := cloud.IsNitroInstanceType(instanceType)
+		availableAttachments := cloud.GetMaxAttachments(isNitro)
+
+		reservedVolumeAttachments := d.options.ReservedVolumeAttachments
+		if reservedVolumeAttachments == -1 {
+			reservedVolumeAttachments = d.metadata.GetNumBlockDeviceMappings() + 1 // +1 for the root device
+		}
+		dedicatedLimit := cloud.GetDedicatedLimitForInstanceType(instanceType)
+		maxEBSAttachments, hasMaxVolumeLimit := cloud.GetEBSLimitForInstanceType(instanceType)
+		reservedSlots := cloud.GetReservedSlotsForInstanceType(instanceType)
+		if hasMaxVolumeLimit {
+			availableAttachments = min(maxEBSAttachments, availableAttachments)
+		}
+		if dedicatedLimit != 0 {
+			availableAttachments = dedicatedLimit
+		} else if isNitro {
+			enis := d.metadata.GetNumAttachedENIs()
+			if hasMaxVolumeLimit {
+				availableAttachments = availableAttachments - (enis - 1) - reservedSlots
+			} else {
+				availableAttachments = availableAttachments - enis - reservedSlots
+			}
+		}
+		availableAttachments -= reservedVolumeAttachments
+		if availableAttachments <= 0 {
+			availableAttachments = 1
+		}
+		enis := d.metadata.GetNumAttachedENIs()
+		maxAttachments := maxEBSAttachments
+		if !hasMaxVolumeLimit {
+			maxAttachments = cloud.GetMaxAttachments(isNitro)
+		}
+		if dedicatedLimit != 0 {
+			maxAttachments = dedicatedLimit
+		}
+		klog.V(4).InfoS("NodeGetInfo: Inputs used to calculate CSI Node Allocatable Info",
+			"instanceType", instanceType,
+			"maxAttachments", maxAttachments,
+			"numENIs", enis,
+			"reservedVolumeAttachments", reservedVolumeAttachments,
+			"reservedSlots", reservedSlots,
+			"numBlockDevices", d.metadata.GetNumBlockDeviceMappings(),
+		)
+		klog.V(4).InfoS("Node Allocatables", "count", availableAttachments)
+	}
+
 	segments := map[string]string{
 		ZoneTopologyKey:          zone,
 		WellKnownZoneTopologyKey: zone,
@@ -803,7 +853,6 @@ func (d *NodeService) getVolumesLimit() int64 {
 	if availableAttachments <= 0 {
 		availableAttachments = 1
 	}
-
 	return int64(availableAttachments)
 }