feat(vm): add support for disk cache option (#443)

docs/resources/virtual_environment_vm.md

@@ -224,6 +224,14 @@ output "ubuntu_vm_public_key" {
     - `units` - (Optional) The CPU units (defaults to `1024`).
 - `description` - (Optional) The description.
 - `disk` - (Optional) A disk (multiple blocks supported).
+    - `cache` - (Optional) The cache type (defaults to `none`).
+        - `none` - No cache.
+        - `directsync` - Write to the host cache and wait for completion.
+        - `writethrough` - Write to the host cache, but write through to
+          the guest.
+        - `writeback` - Write to the host cache, but write back to the
+          guest when possible.
+        - `unsafe` - Write directly to the disk bypassing the host cache.
     - `datastore_id` - (Optional) The identifier for the datastore to create
       the disk in (defaults to `local-lvm`).
     - `discard` - (Optional) Whether to pass discard/trim requests to the

example/resource_virtual_environment_vm.tf

@@ -31,6 +31,7 @@ resource "proxmox_virtual_environment_vm" "example_template" {
     file_id      = proxmox_virtual_environment_file.ubuntu_cloud_image.id
     interface    = "scsi0"
     discard      = "on"
+    cache        = "writeback"
     ssd          = true
   }
 

proxmox/nodes/vms/vms_types.go

@@ -168,6 +168,7 @@ type CustomStorageDevice struct {
 	AIO                     *string           `json:"aio,omitempty"         url:"aio,omitempty"`
 	BackupEnabled           *types.CustomBool `json:"backup,omitempty"      url:"backup,omitempty,int"`
 	BurstableReadSpeedMbps  *int              `json:"mbps_rd_max,omitempty" url:"mbps_rd_max,omitempty"`
+	Cache                   *string           `json:"cache,omitempty"       url:"cache,omitempty"`
 	BurstableWriteSpeedMbps *int              `json:"mbps_wr_max,omitempty" url:"mbps_wr_max,omitempty"`
 	Discard                 *string           `json:"discard,omitempty"     url:"discard,omitempty"`
 	Enabled                 bool              `json:"-"                     url:"-"`
@@ -1146,6 +1147,10 @@ func (r CustomStorageDevice) EncodeValues(key string, v *url.Values) error {
 		values = append(values, fmt.Sprintf("discard=%s", *r.Discard))
 	}
 
+	if r.Cache != nil && *r.Cache != "" {
+		values = append(values, fmt.Sprintf("cache=%s", *r.Cache))
+	}
+
 	v.Add(key, strings.Join(values, ","))
 
 	return nil
@@ -1765,11 +1770,14 @@ func (r *CustomStorageDevice) UnmarshalJSON(b []byte) error {
 			switch v[0] {
 			case "aio":
 				r.AIO = &v[1]
+
 			case "backup":
 				bv := types.CustomBool(v[1] == "1")
 				r.BackupEnabled = &bv
+
 			case "file":
 				r.FileVolume = v[1]
+
 			case "mbps_rd":
 				iv, err := strconv.Atoi(v[1])
 				if err != nil {
@@ -1800,22 +1808,30 @@ func (r *CustomStorageDevice) UnmarshalJSON(b []byte) error {
 				r.BurstableWriteSpeedMbps = &iv
 			case "media":
 				r.Media = &v[1]
+
 			case "size":
 				r.Size = new(types.DiskSize)
 				err := r.Size.UnmarshalJSON([]byte(v[1]))
 				if err != nil {
 					return fmt.Errorf("failed to unmarshal disk size: %w", err)
 				}
+
 			case "format":
 				r.Format = &v[1]
+
 			case "iothread":
 				bv := types.CustomBool(v[1] == "1")
 				r.IOThread = &bv
+
 			case "ssd":
 				bv := types.CustomBool(v[1] == "1")
 				r.SSD = &bv
+
 			case "discard":
 				r.Discard = &v[1]
+
+			case "cache":
+				r.Cache = &v[1]
 			}
 		}
 	}

proxmox/nodes/vms/vms_types_test.go

@@ -24,8 +24,9 @@ func TestCustomStorageDevice_UnmarshalJSON(t *testing.T) {
 	}{
 		{
 			name: "simple volume",
-			line: `"local-lvm:vm-2041-disk-0,discard=on,ssd=1,iothread=1,size=8G"`,
+			line: `"local-lvm:vm-2041-disk-0,discard=on,ssd=1,iothread=1,size=8G,cache=writeback"`,
 			want: &CustomStorageDevice{
+				Cache:      types.StrPtr("writeback"),
 				Discard:    types.StrPtr("on"),
 				Enabled:    true,
 				FileVolume: "local-lvm:vm-2041-disk-0",

proxmoxtf/resource/vm.go

@@ -64,6 +64,7 @@ const (
 	dvResourceVirtualEnvironmentVMDiskIOThread                      = false
 	dvResourceVirtualEnvironmentVMDiskSSD                           = false
 	dvResourceVirtualEnvironmentVMDiskDiscard                       = ""
+	dvResourceVirtualEnvironmentVMDiskCache                         = ""
 	dvResourceVirtualEnvironmentVMDiskSpeedRead                     = 0
 	dvResourceVirtualEnvironmentVMDiskSpeedReadBurstable            = 0
 	dvResourceVirtualEnvironmentVMDiskSpeedWrite                    = 0
@@ -163,6 +164,7 @@ const (
 	mkResourceVirtualEnvironmentVMDiskIOThread                      = "iothread"
 	mkResourceVirtualEnvironmentVMDiskSSD                           = "ssd"
 	mkResourceVirtualEnvironmentVMDiskDiscard                       = "discard"
+	mkResourceVirtualEnvironmentVMDiskCache                         = "cache"
 	mkResourceVirtualEnvironmentVMDiskSpeed                         = "speed"
 	mkResourceVirtualEnvironmentVMDiskSpeedRead                     = "read"
 	mkResourceVirtualEnvironmentVMDiskSpeedReadBurstable            = "read_burstable"
@@ -568,6 +570,7 @@ func VM() *schema.Resource {
 							mkResourceVirtualEnvironmentVMDiskIOThread:    dvResourceVirtualEnvironmentVMDiskIOThread,
 							mkResourceVirtualEnvironmentVMDiskSSD:         dvResourceVirtualEnvironmentVMDiskSSD,
 							mkResourceVirtualEnvironmentVMDiskDiscard:     dvResourceVirtualEnvironmentVMDiskDiscard,
+							mkResourceVirtualEnvironmentVMDiskCache:       dvResourceVirtualEnvironmentVMDiskCache,
 						},
 					}, nil
 				},
@@ -625,6 +628,21 @@ func VM() *schema.Resource {
 							Optional:    true,
 							Default:     dvResourceVirtualEnvironmentVMDiskDiscard,
 						},
+						mkResourceVirtualEnvironmentVMDiskCache: {
+							Type:        schema.TypeString,
+							Description: "The drive’s cache mode",
+							Optional:    true,
+							Default:     dvResourceVirtualEnvironmentVMDiskCache,
+							ValidateDiagFunc: validation.ToDiagFunc(
+								validation.StringInSlice([]string{
+									"none",
+									"writethrough",
+									"writeback",
+									"unsafe",
+									"directsync",
+								}, false),
+							),
+						},
 						mkResourceVirtualEnvironmentVMDiskSpeed: {
 							Type:        schema.TypeList,
 							Description: "The speed limits",
@@ -2360,6 +2378,7 @@ func vmCreateCustomDisks(ctx context.Context, d *schema.ResourceData, m interfac
 		ioThread := types.CustomBool(block[mkResourceVirtualEnvironmentVMDiskIOThread].(bool))
 		ssd := types.CustomBool(block[mkResourceVirtualEnvironmentVMDiskSSD].(bool))
 		discard, _ := block[mkResourceVirtualEnvironmentVMDiskDiscard].(string)
+		cache, _ := block[mkResourceVirtualEnvironmentVMDiskCache].(string)
 
 		if fileFormat == "" {
 			fileFormat = dvResourceVirtualEnvironmentVMDiskFileFormat
@@ -2393,6 +2412,10 @@ func vmCreateCustomDisks(ctx context.Context, d *schema.ResourceData, m interfac
 			diskOptions += fmt.Sprintf(",discard=%s", discard)
 		}
 
+		if cache != "" {
+			diskOptions += fmt.Sprintf(",cache=%s", cache)
+		}
+
 		if speedLimitRead > 0 {
 			diskOptions += fmt.Sprintf(",mbps_rd=%d", speedLimitRead)
 		}
@@ -2722,6 +2745,7 @@ func vmGetDiskDeviceObjects(
 		ioThread := types.CustomBool(block[mkResourceVirtualEnvironmentVMDiskIOThread].(bool))
 		ssd := types.CustomBool(block[mkResourceVirtualEnvironmentVMDiskSSD].(bool))
 		discard := block[mkResourceVirtualEnvironmentVMDiskDiscard].(string)
+		cache := block[mkResourceVirtualEnvironmentVMDiskCache].(string)
 
 		speedBlock, err := structure.GetSchemaBlock(
 			resource,
@@ -2752,6 +2776,7 @@ func vmGetDiskDeviceObjects(
 		diskDevice.SizeInt = &size
 		diskDevice.IOThread = &ioThread
 		diskDevice.Discard = &discard
+		diskDevice.Cache = &cache
 
 		if !strings.HasPrefix(diskInterface, "virtio") {
 			diskDevice.SSD = &ssd
@@ -3480,6 +3505,12 @@ func vmReadCustom(
 			disk[mkResourceVirtualEnvironmentVMDiskDiscard] = ""
 		}
 
+		if dd.Cache != nil {
+			disk[mkResourceVirtualEnvironmentVMDiskCache] = *dd.Cache
+		} else {
+			disk[mkResourceVirtualEnvironmentVMDiskCache] = ""
+		}
+
 		diskMap[di] = disk
 	}