Allow HugePages in emptyDir.medium. (#2395)

* Allow HugePages in emptyDir.medium.

* Add acceptance test for HugePages-1Gi.

* Reformat.

* add changelog-entry

---------

Co-authored-by: BBBmau <[email protected]>

Author: gram-signal

.changelog/2395.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+`kubernetes/kubernetes_deployment_v1`: Add support for `HugePages` in `emptyDir.medium`
+```

kubernetes/resource_kubernetes_deployment_v1_test.go

@@ -820,6 +820,33 @@ func TestAccKubernetesDeploymentV1_with_empty_dir_volume(t *testing.T) {
 	})
 }
 
+func TestAccKubernetesDeploymentV1_with_empty_dir_huge_page(t *testing.T) {
+	var conf appsv1.Deployment
+
+	imageName := busyboxImage
+	deploymentName := fmt.Sprintf("tf-acc-test-%s", acctest.RandStringFromCharSet(10, acctest.CharSetAlphaNum))
+	resourceName := "kubernetes_deployment_v1.test"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:          func() { testAccPreCheck(t) },
+		ProviderFactories: testAccProviderFactories,
+		CheckDestroy:      testAccCheckKubernetesDeploymentV1Destroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccKubernetesDeploymentV1ConfigWithEmptyDirHugePage(deploymentName, imageName),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					testAccCheckKubernetesDeploymentV1Exists(resourceName, &conf),
+					resource.TestCheckResourceAttr(resourceName, "spec.0.template.0.spec.0.container.0.image", imageName),
+					resource.TestCheckResourceAttr(resourceName, "spec.0.template.0.spec.0.container.0.volume_mount.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "spec.0.template.0.spec.0.container.0.volume_mount.0.mount_path", "/cache"),
+					resource.TestCheckResourceAttr(resourceName, "spec.0.template.0.spec.0.container.0.volume_mount.0.name", "cache-volume"),
+					resource.TestCheckResourceAttr(resourceName, "spec.0.template.0.spec.0.volume.0.empty_dir.0.medium", "HugePages-1Gi"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccKubernetesDeploymentV1Update_basic(t *testing.T) {
 	var conf1, conf2 appsv1.Deployment
 	resourceName := "kubernetes_deployment_v1.test"
@@ -2608,6 +2635,59 @@ func testAccKubernetesDeploymentV1ConfigWithEmptyDirVolumes(deploymentName, imag
 `, deploymentName, imageName)
 }
 
+func testAccKubernetesDeploymentV1ConfigWithEmptyDirHugePage(deploymentName, imageName string) string {
+	return fmt.Sprintf(`resource "kubernetes_deployment_v1" "test" {
+  metadata {
+    name = "%s"
+
+    labels = {
+      Test = "TfAcceptanceTest"
+    }
+  }
+
+  spec {
+    replicas = 0 # We request zero replicas, since the K8S backing this test may not have huge pages available.
+    selector {
+      match_labels = {
+        Test = "TfAcceptanceTest"
+      }
+    }
+
+    template {
+      metadata {
+        labels = {
+          Test = "TfAcceptanceTest"
+        }
+      }
+
+      spec {
+        container {
+          image   = "%s"
+          name    = "containername"
+          command = ["sleep", "300"]
+
+          volume_mount {
+            mount_path = "/cache"
+            name       = "cache-volume"
+          }
+        }
+
+        volume {
+          name = "cache-volume"
+
+          empty_dir {
+            medium = "HugePages-1Gi"
+          }
+        }
+
+        termination_grace_period_seconds = 1
+      }
+    }
+  }
+}
+`, deploymentName, imageName)
+}
+
 func testAccKubernetesDeploymentV1ConfigWithEmptyDirVolumesModified(deploymentName, imageName string) string {
 	return fmt.Sprintf(`resource "kubernetes_deployment_v1" "test" {
   metadata {

kubernetes/schema_pod_spec.go

@@ -4,6 +4,8 @@
 package kubernetes
 
 import (
+	"fmt"
+
 	corev1 "k8s.io/api/core/v1"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
@@ -707,6 +709,15 @@ func volumeSchema(isUpdatable bool) *schema.Resource {
 		},
 	}
 
+	validEmptyDirMediums := []string{
+		string(corev1.StorageMediumDefault),
+		string(corev1.StorageMediumMemory),
+		string(corev1.StorageMediumHugePages),
+		// This is possibly not an exhaustive list, but it does cover the
+		// common cases from x86_64 architectures.
+		string(corev1.StorageMediumHugePagesPrefix) + "2Mi",
+		string(corev1.StorageMediumHugePagesPrefix) + "1Gi",
+	}
 	v["empty_dir"] = &schema.Schema{
 		Type:        schema.TypeList,
 		Description: "EmptyDir represents a temporary directory that shares a pod's lifetime. More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir",
@@ -715,15 +726,12 @@ func volumeSchema(isUpdatable bool) *schema.Resource {
 		Elem: &schema.Resource{
 			Schema: map[string]*schema.Schema{
 				"medium": {
-					Type:        schema.TypeString,
-					Description: `What type of storage medium should back this directory. The default is "" which means to use the node's default medium. Must be an empty string (default) or Memory. More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir`,
-					Optional:    true,
-					Default:     "",
-					ForceNew:    !isUpdatable,
-					ValidateFunc: validation.StringInSlice([]string{
-						string(corev1.StorageMediumDefault),
-						string(corev1.StorageMediumMemory),
-					}, false),
+					Type:         schema.TypeString,
+					Description:  fmt.Sprintf(`What type of storage medium should back this directory. The default is "" which means to use the node's default medium. Must be one of %q. More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir`, validEmptyDirMediums),
+					Optional:     true,
+					Default:      "",
+					ForceNew:     !isUpdatable,
+					ValidateFunc: validation.StringInSlice(validEmptyDirMediums, false),
 				},
 				"size_limit": {
 					Type:             schema.TypeString,