Update container hugepage limit when creating the container

Unit test for updating container hugepage limit
Add warning message about ignoring case.
Update error handling about hugepage size requirements

Signed-off-by: sewon.oh <sewon.oh@samsung.com>

pkg/apis/core/v1/helper/helpers.go

@@ -85,6 +85,24 @@ func HugePageSizeFromResourceName(name v1.ResourceName) (resource.Quantity, erro
 	return resource.ParseQuantity(pageSize)
 }
 
+// HugePageUnitSizeFromByteSize returns hugepage size has the format.
+// `size` must be guaranteed to divisible into the largest units that can be expressed.
+// <size><unit-prefix>B (1024 = "1KB", 1048576 = "1MB", etc).
+func HugePageUnitSizeFromByteSize(size int64) (string, error) {
+	// hugePageSizeUnitList is borrowed from opencontainers/runc/libcontainer/cgroups/utils.go
+	var hugePageSizeUnitList = []string{"B", "KB", "MB", "GB", "TB", "PB"}
+	idx := 0
+	len := len(hugePageSizeUnitList) - 1
+	for size%1024 == 0 && idx < len {
+		size /= 1024
+		idx++
+	}
+	if size > 1024 && idx < len {
+		return "", fmt.Errorf("size: %d%s must be guaranteed to divisible into the largest units", size, hugePageSizeUnitList[idx])
+	}
+	return fmt.Sprintf("%d%s", size, hugePageSizeUnitList[idx]), nil
+}
+
 // IsOvercommitAllowed returns true if the resource is in the default
 // namespace and is not hugepages.
 func IsOvercommitAllowed(name v1.ResourceName) bool {

pkg/apis/core/v1/helper/helpers_test.go

@@ -21,7 +21,7 @@ import (
 	"reflect"
 	"testing"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -1398,3 +1398,47 @@ func TestNodeSelectorRequirementKeyExistsInNodeSelectorTerms(t *testing.T) {
 		}
 	}
 }
+
+func TestHugePageUnitSizeFromByteSize(t *testing.T) {
+	tests := []struct {
+		size     int64
+		expected string
+		wantErr  bool
+	}{
+		{
+			size:     1024,
+			expected: "1KB",
+			wantErr:  false,
+		},
+		{
+			size:     33554432,
+			expected: "32MB",
+			wantErr:  false,
+		},
+		{
+			size:     3221225472,
+			expected: "3GB",
+			wantErr:  false,
+		},
+		{
+			size:     1024 * 1024 * 1023 * 3,
+			expected: "3069MB",
+			wantErr:  true,
+		},
+	}
+	for _, test := range tests {
+		size := test.size
+		result, err := HugePageUnitSizeFromByteSize(size)
+		if err != nil {
+			if test.wantErr {
+				t.Logf("HugePageUnitSizeFromByteSize() expected error = %v", err)
+			} else {
+				t.Errorf("HugePageUnitSizeFromByteSize() error = %v, wantErr %v", err, test.wantErr)
+			}
+			continue
+		}
+		if test.expected != result {
+			t.Errorf("HugePageUnitSizeFromByteSize() expected %v but got %v", test.expected, result)
+		}
+	}
+}