Allow specifying volume device

admission/plugin/machinevolumedevices/admission.go

@@ -0,0 +1,118 @@
+// Copyright 2022 OnMetal authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package machinevolumedevices
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/onmetal/onmetal-api/admission/plugin/machinevolumedevices/device"
+	"github.com/onmetal/onmetal-api/apis/compute"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apiserver/pkg/admission"
+)
+
+// PluginName indicates name of admission plugin.
+const PluginName = "MachineVolumeDevices"
+
+// Register registers a plugin
+func Register(plugins *admission.Plugins) {
+	plugins.Register(PluginName, func(config io.Reader) (admission.Interface, error) {
+		return NewMachineVolumeDevices(), nil
+	})
+}
+
+type MachineVolumeDevices struct {
+	*admission.Handler
+}
+
+func NewMachineVolumeDevices() *MachineVolumeDevices {
+	return &MachineVolumeDevices{
+		Handler: admission.NewHandler(admission.Create, admission.Update),
+	}
+}
+
+func (d *MachineVolumeDevices) Admit(ctx context.Context, a admission.Attributes, o admission.ObjectInterfaces) error {
+	if shouldIgnore(a) {
+		return nil
+	}
+
+	machine, ok := a.GetObject().(*compute.Machine)
+	if !ok {
+		return apierrors.NewBadRequest("Resource was marked with kind Machine but was unable to be converted")
+	}
+
+	namer, err := deviceNamerFromMachineVolumes(machine)
+	if err != nil {
+		return apierrors.NewBadRequest("Machine has conflicting volume device names")
+	}
+
+	for i := range machine.Spec.Volumes {
+		volume := &machine.Spec.Volumes[i]
+		if volume.Device != "" {
+			continue
+		}
+
+		dev, err := namer.Generate(device.VirtioPrefix) // TODO: We should have a better way for a device prefix.
+		if err != nil {
+			return apierrors.NewBadRequest("No device names left for machine")
+		}
+
+		volume.Device = dev
+	}
+
+	return nil
+}
+
+func shouldIgnore(a admission.Attributes) bool {
+	if a.GetKind().GroupKind() != compute.Kind("Machine") {
+		return true
+	}
+
+	machine, ok := a.GetObject().(*compute.Machine)
+	if !ok {
+		return true
+	}
+
+	return !machineHasAnyVolumeWithoutDevice(machine)
+}
+
+func machineHasAnyVolumeWithoutDevice(machine *compute.Machine) bool {
+	for _, volume := range machine.Spec.Volumes {
+		if volume.Device == "" {
+			return true
+		}
+	}
+	return false
+}
+
+func deviceNamerFromMachineVolumes(machine *compute.Machine) (*device.Namer, error) {
+	namer := device.NewNamer()
+
+	// Observe reserved names.
+	if err := namer.Observe(device.Name(device.VirtioPrefix, 0)); err != nil {
+		return nil, err
+	}
+
+	for _, volume := range machine.Spec.Volumes {
+		if dev := volume.Device; dev != "" {
+			if err := namer.Observe(dev); err != nil {
+				return nil, fmt.Errorf("error observing device %s: %w", dev, err)
+			}
+		}
+	}
+	return namer, nil
+}

admission/plugin/machinevolumedevices/admission_test.go

@@ -0,0 +1,119 @@
+// Copyright 2022 OnMetal authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package machinevolumedevices_test
+
+import (
+	"context"
+
+	. "github.com/onmetal/onmetal-api/admission/plugin/machinevolumedevices"
+	"github.com/onmetal/onmetal-api/apis/compute"
+	"github.com/onmetal/onmetal-api/apis/storage"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apiserver/pkg/admission"
+)
+
+var _ = Describe("Admission", func() {
+	var (
+		plugin *MachineVolumeDevices
+	)
+	BeforeEach(func() {
+		plugin = NewMachineVolumeDevices()
+	})
+
+	It("should ignore non-machine objects", func() {
+		volume := &storage.Volume{
+			ObjectMeta: metav1.ObjectMeta{
+				Namespace: "foo",
+				Name:      "bar",
+			},
+		}
+		origVolume := volume.DeepCopy()
+		Expect(plugin.Admit(
+			context.TODO(),
+			admission.NewAttributesRecord(
+				volume,
+				nil,
+				storage.Kind("Volume").WithVersion("version"),
+				volume.Namespace,
+				volume.Name,
+				storage.Resource("volumes").WithVersion("version"),
+				"",
+				admission.Create,
+				&metav1.CreateOptions{},
+				false,
+				nil,
+			),
+			nil,
+		)).NotTo(HaveOccurred())
+		Expect(volume).To(Equal(origVolume))
+	})
+
+	It("should add volume device names when unset", func() {
+		machine := &compute.Machine{
+			ObjectMeta: metav1.ObjectMeta{
+				Namespace: "foo",
+				Name:      "bar",
+			},
+			Spec: compute.MachineSpec{
+				Volumes: []compute.Volume{
+					{
+						Name:   "foo",
+						Device: "vdb",
+					},
+					{
+						Name: "bar",
+					},
+					{
+						Name: "baz",
+					},
+				},
+			},
+		}
+		Expect(plugin.Admit(
+			context.TODO(),
+			admission.NewAttributesRecord(
+				machine,
+				nil,
+				compute.Kind("Machine").WithVersion("version"),
+				machine.Namespace,
+				machine.Name,
+				compute.Resource("machines").WithVersion("version"),
+				"",
+				admission.Create,
+				&metav1.CreateOptions{},
+				false,
+				nil,
+			),
+			nil,
+		)).NotTo(HaveOccurred())
+
+		Expect(machine.Spec.Volumes).To(Equal([]compute.Volume{
+			{
+				Name:   "foo",
+				Device: "vdb",
+			},
+			{
+				Name:   "bar",
+				Device: "vdc",
+			},
+			{
+				Name:   "baz",
+				Device: "vdd",
+			},
+		}))
+	})
+})