Extend NodeConfig with loop device management

deploy/operator.yaml

@@ -345,6 +345,26 @@ spec:
                             type: string
                         type: object
                       type: array
+                    loopDevices:
+                      description: loops is a list of loop device configurations.
+                      items:
+                        description: LoopDeviceConfiguration specifies loop device configuration options.
+                        properties:
+                          imagePath:
+                            description: imagePath specifies path on host where backing image file for loop device should be located.
+                            type: string
+                          name:
+                            description: name specifies the name of the symlink that will point to actual loop device, created under `/dev/loops/`.
+                            type: string
+                          size:
+                            anyOf:
+                              - type: integer
+                              - type: string
+                            description: size specifies the size of the loop device.
+                            pattern: ^(\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|([eE](\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))))?$
+                            x-kubernetes-int-or-string: true
+                        type: object
+                      type: array
                     mounts:
                       description: mounts is a list of mount configuration.
                       items:

docs/source/api-reference/groups/scylla.scylladb.com/nodeconfigs.rst

@@ -109,6 +109,9 @@ object
    * - :ref:`filesystems<api-scylla.scylladb.com-nodeconfigs-v1alpha1-.spec.localDiskSetup.filesystems[]>`
      - array (object)
      - filesystems is a list of filesystem configurations.
+   * - :ref:`loopDevices<api-scylla.scylladb.com-nodeconfigs-v1alpha1-.spec.localDiskSetup.loopDevices[]>`
+     - array (object)
+     - loops is a list of loop device configurations.
    * - :ref:`mounts<api-scylla.scylladb.com-nodeconfigs-v1alpha1-.spec.localDiskSetup.mounts[]>`
      - array (object)
      - mounts is a list of mount configuration.
@@ -144,6 +147,37 @@ object
      - string
      - type is a desired filesystem type.
 
+.. _api-scylla.scylladb.com-nodeconfigs-v1alpha1-.spec.localDiskSetup.loopDevices[]:
+
+.spec.localDiskSetup.loopDevices[]
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Description
+"""""""""""
+LoopDeviceConfiguration specifies loop device configuration options.
+
+Type
+""""
+object
+
+
+.. list-table::
+   :widths: 25 10 150
+   :header-rows: 1
+
+   * - Property
+     - Type
+     - Description
+   * - imagePath
+     - string
+     - imagePath specifies path on host where backing image file for loop device should be located.
+   * - name
+     - string
+     - name specifies the name of the symlink that will point to actual loop device, created under `/dev/loops/`.
+   * - size
+     - 
+     - size specifies the size of the loop device.
+
 .. _api-scylla.scylladb.com-nodeconfigs-v1alpha1-.spec.localDiskSetup.mounts[]:
 
 .spec.localDiskSetup.mounts[]

pkg/api/scylla/v1alpha1/scylla.scylladb.com_nodeconfigs.yaml

@@ -52,6 +52,26 @@ spec:
                             type: string
                         type: object
                       type: array
+                    loopDevices:
+                      description: loops is a list of loop device configurations.
+                      items:
+                        description: LoopDeviceConfiguration specifies loop device configuration options.
+                        properties:
+                          imagePath:
+                            description: imagePath specifies path on host where backing image file for loop device should be located.
+                            type: string
+                          name:
+                            description: name specifies the name of the symlink that will point to actual loop device, created under `/dev/loops/`.
+                            type: string
+                          size:
+                            anyOf:
+                              - type: integer
+                              - type: string
+                            description: size specifies the size of the loop device.
+                            pattern: ^(\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|([eE](\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))))?$
+                            x-kubernetes-int-or-string: true
+                        type: object
+                      type: array
                     mounts:
                       description: mounts is a list of mount configuration.
                       items:

pkg/api/scylla/v1alpha1/types_nodeconfig.go

@@ -18,6 +18,7 @@ package v1alpha1
 
 import (
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -155,8 +156,23 @@ type MountConfiguration struct {
 	UnsupportedOptions []string `json:"unsupportedOptions"`
 }
 
+// LoopDeviceConfiguration specifies loop device configuration options.
+type LoopDeviceConfiguration struct {
+	// name specifies the name of the symlink that will point to actual loop device, created under `/dev/loops/`.
+	Name string `json:"name"`
+
+	// imagePath specifies path on host where backing image file for loop device should be located.
+	ImagePath string `json:"imagePath"`
+
+	// size specifies the size of the loop device.
+	Size resource.Quantity `json:"size"`
+}
+
 // LocalDiskSetup specifies configuration of local disk setup.
 type LocalDiskSetup struct {
+	// loops is a list of loop device configurations.
+	LoopDevices []LoopDeviceConfiguration `json:"loopDevices"`
+
 	// raids is a list of raid configurations.
 	RAIDs []RAIDConfiguration `json:"raids"`
 

pkg/api/scylla/validation/nodeconfig_validation.go

@@ -4,6 +4,8 @@ package validation
 
 import (
 	scyllav1alpha1 "github.com/scylladb/scylla-operator/pkg/api/scylla/v1alpha1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	apimachineryvalidation "k8s.io/apimachinery/pkg/api/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
 
@@ -90,5 +92,21 @@ func ValidateNodeConfigUpdate(new, old *scyllav1alpha1.NodeConfig) field.ErrorLi
 func ValidateNodeConfigSpecUpdate(new, old *scyllav1alpha1.NodeConfig, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}
 
+	oldLoopDevicesSizes := make(map[string]resource.Quantity)
+	if old.Spec.LocalDiskSetup != nil {
+		for _, ldc := range old.Spec.LocalDiskSetup.LoopDevices {
+			oldLoopDevicesSizes[ldc.Name] = ldc.Size
+		}
+	}
+
+	if new.Spec.LocalDiskSetup != nil {
+		for i, ld := range new.Spec.LocalDiskSetup.LoopDevices {
+			oldSize, ok := oldLoopDevicesSizes[ld.Name]
+			if ok && !ld.Size.Equal(oldSize) {
+				allErrs = append(allErrs, apimachineryvalidation.ValidateImmutableField(ld.Size.String(), oldSize.String(), fldPath.Child("localDiskSetup", "loopDevices").Index(i).Child("size"))...)
+			}
+		}
+	}
+
 	return allErrs
 }

pkg/api/scylla/validation/nodeconfig_validation_test.go

@@ -3,13 +3,15 @@
 package validation_test
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
 	scyllav1alpha1 "github.com/scylladb/scylla-operator/pkg/api/scylla/v1alpha1"
 	"github.com/scylladb/scylla-operator/pkg/api/scylla/validation"
 	"github.com/scylladb/scylla-operator/pkg/test/unit"
+	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
 
@@ -236,6 +238,35 @@ func TestValidateNodeConfigUpdate(t *testing.T) {
 			},
 			expectedErrorString: `[spec.localDiskSetup.mounts[1].mountPoint: Duplicate value: "/mnt/foo", spec.localDiskSetup.mounts[3].mountPoint: Duplicate value: "/mnt/bar"]`,
 		},
+		{
+			name: "immutable loop device size",
+			old: func() *scyllav1alpha1.NodeConfig {
+				nc := validNodeConfig.DeepCopy()
+				nc.Spec.LocalDiskSetup.LoopDevices = []scyllav1alpha1.LoopDeviceConfiguration{
+					{
+						Name:      "foo",
+						ImagePath: "/mnt/foo.img",
+						Size:      resource.MustParse("100Mi"),
+					},
+				}
+				return nc
+			}(),
+			new: func() *scyllav1alpha1.NodeConfig {
+				nc := validNodeConfig.DeepCopy()
+				nc.Spec.LocalDiskSetup.LoopDevices = []scyllav1alpha1.LoopDeviceConfiguration{
+					{
+						Name:      "foo",
+						ImagePath: "/mnt/foo.img",
+						Size:      resource.MustParse("200Mi"),
+					},
+				}
+				return nc
+			}(),
+			expectedErrorList: field.ErrorList{
+				&field.Error{Type: field.ErrorTypeInvalid, Field: "spec.localDiskSetup.loopDevices[0].size", BadValue: "200Mi", Detail: "field is immutable"},
+			},
+			expectedErrorString: fmt.Sprintf(`spec.localDiskSetup.loopDevices[0].size: Invalid value: "200Mi": field is immutable`),
+		},
 	}
 
 	for i := range tt {

pkg/controller/nodesetup/conditions.go

@@ -11,4 +11,7 @@ const (
 
 	mountControllerNodeProgressingConditionFormat = "MountControllerNode%sProgressing"
 	mountControllerNodeDegradedConditionFormat    = "MountControllerNode%sDegraded"
+
+	loopDeviceControllerNodeProgressingConditionFormat = "LoopDeviceControllerNode%sProgressing"
+	loopDeviceControllerNodeDegradedConditionFormat    = "LoopDeviceControllerNode%sDegraded"
 )

pkg/controller/nodesetup/sync.go

@@ -41,6 +41,19 @@ func (nsc *Controller) sync(ctx context.Context) error {
 		return nsc.updateNodeStatus(ctx, nc, conditions)
 	}
 
+	err = controllerhelpers.RunSync(
+		&conditions,
+		fmt.Sprintf(loopDeviceControllerNodeProgressingConditionFormat, nsc.nodeName),
+		fmt.Sprintf(loopDeviceControllerNodeDegradedConditionFormat, nsc.nodeName),
+		nc.Generation,
+		func() ([]metav1.Condition, error) {
+			return nsc.syncLoopDevices(ctx, nc)
+		},
+	)
+	if err != nil {
+		errs = append(errs, fmt.Errorf("can't sync loop devices: %w", err))
+	}
+
 	err = controllerhelpers.RunSync(
 		&conditions,
 		fmt.Sprintf(raidControllerNodeProgressingConditionFormat, nsc.nodeName),

pkg/controller/nodesetup/sync_filesystems.go

@@ -23,7 +23,7 @@ func (nsc *Controller) syncFilesystems(ctx context.Context, nc *scyllav1alpha1.N
 	}
 
 	for _, fs := range nc.Spec.LocalDiskSetup.Filesystems {
-		device, err := disks.GetRAIDDeviceWithName(ctx, nsc.executor, nsc.devtmpfsPath, fs.Device)
+		device, err := disks.GetDeviceWithName(ctx, nsc.executor, nsc.devtmpfsPath, fs.Device)
 		if err != nil {
 			errs = append(errs, fmt.Errorf("can't resolve RAID device %q: %w", fs.Device, err))
 			continue