From 74ecab5f7eddde344e4dcc296a7c16075a5be381 Mon Sep 17 00:00:00 2001
From: Derek Carr <decarr@redhat.com>
Date: Fri, 6 Nov 2020 14:22:53 -0500
Subject: [PATCH] Downward API hugepages

Kubernetes-commit: 45bd6cb186c05eb3a6cdb2cc4927bbcb50a8ff74
---
 pkg/cmd/set/env/env_resolve.go | 28 +++++++++++++++++++++++++++-
 pkg/util/resource/resource.go  | 22 +++++++++++++++++++++-
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/pkg/cmd/set/env/env_resolve.go b/pkg/cmd/set/env/env_resolve.go
index 93e28f98a..e45b686b3 100644
--- a/pkg/cmd/set/env/env_resolve.go
+++ b/pkg/cmd/set/env/env_resolve.go
@@ -199,7 +199,20 @@ func extractContainerResourceValue(fs *corev1.ResourceFieldSelector, container *
 	case "requests.ephemeral-storage":
 		return convertResourceEphemeralStorageToString(container.Resources.Requests.StorageEphemeral(), divisor)
 	}
-
+	// handle extended standard resources with dynamic names
+	// example: requests.hugepages-<pageSize> or limits.hugepages-<pageSize>
+	if strings.HasPrefix(fs.Resource, "requests.") {
+		resourceName := corev1.ResourceName(strings.TrimPrefix(fs.Resource, "requests."))
+		if IsHugePageResourceName(resourceName) {
+			return convertResourceHugePagesToString(container.Resources.Requests.Name(resourceName, resource.BinarySI), divisor)
+		}
+	}
+	if strings.HasPrefix(fs.Resource, "limits.") {
+		resourceName := corev1.ResourceName(strings.TrimPrefix(fs.Resource, "limits."))
+		if IsHugePageResourceName(resourceName) {
+			return convertResourceHugePagesToString(container.Resources.Limits.Name(resourceName, resource.BinarySI), divisor)
+		}
+	}
 	return "", fmt.Errorf("Unsupported container resource : %v", fs.Resource)
 }
 
@@ -217,6 +230,13 @@ func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Q
 	return strconv.FormatInt(m, 10), nil
 }
 
+// convertResourceHugePagesToString converts hugepages value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceHugePagesToString(hugePages *resource.Quantity, divisor resource.Quantity) (string, error) {
+	m := int64(math.Ceil(float64(hugePages.Value()) / float64(divisor.Value())))
+	return strconv.FormatInt(m, 10), nil
+}
+
 // convertResourceEphemeralStorageToString converts ephemeral storage value to the format of divisor and returns
 // ceiling of the value.
 func convertResourceEphemeralStorageToString(ephemeralStorage *resource.Quantity, divisor resource.Quantity) (string, error) {
@@ -269,3 +289,9 @@ func GetEnvVarRefString(from *corev1.EnvVarSource) string {
 
 	return "invalid valueFrom"
 }
+
+// IsHugePageResourceName returns true if the resource name has the huge page
+// resource prefix.
+func IsHugePageResourceName(name corev1.ResourceName) bool {
+	return strings.HasPrefix(string(name), corev1.ResourceHugePagesPrefix)
+}
diff --git a/pkg/util/resource/resource.go b/pkg/util/resource/resource.go
index 8308f1583..44ddf96ac 100644
--- a/pkg/util/resource/resource.go
+++ b/pkg/util/resource/resource.go
@@ -108,7 +108,20 @@ func ExtractContainerResourceValue(fs *corev1.ResourceFieldSelector, container *
 	case "requests.ephemeral-storage":
 		return convertResourceEphemeralStorageToString(container.Resources.Requests.StorageEphemeral(), divisor)
 	}
-
+	// handle extended standard resources with dynamic names
+	// example: requests.hugepages-<pageSize> or limits.hugepages-<pageSize>
+	if strings.HasPrefix(fs.Resource, "requests.") {
+		resourceName := corev1.ResourceName(strings.TrimPrefix(fs.Resource, "requests."))
+		if IsHugePageResourceName(resourceName) {
+			return convertResourceHugePagesToString(container.Resources.Requests.Name(resourceName, resource.BinarySI), divisor)
+		}
+	}
+	if strings.HasPrefix(fs.Resource, "limits.") {
+		resourceName := corev1.ResourceName(strings.TrimPrefix(fs.Resource, "limits."))
+		if IsHugePageResourceName(resourceName) {
+			return convertResourceHugePagesToString(container.Resources.Limits.Name(resourceName, resource.BinarySI), divisor)
+		}
+	}
 	return "", fmt.Errorf("Unsupported container resource : %v", fs.Resource)
 }
 
@@ -126,6 +139,13 @@ func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Q
 	return strconv.FormatInt(m, 10), nil
 }
 
+// convertResourceHugePagesToString converts hugepages value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceHugePagesToString(hugePages *resource.Quantity, divisor resource.Quantity) (string, error) {
+	m := int64(math.Ceil(float64(hugePages.Value()) / float64(divisor.Value())))
+	return strconv.FormatInt(m, 10), nil
+}
+
 // convertResourceEphemeralStorageToString converts ephemeral storage value to the format of divisor and returns
 // ceiling of the value.
 func convertResourceEphemeralStorageToString(ephemeralStorage *resource.Quantity, divisor resource.Quantity) (string, error) {