Merge branch 'CNT-3932/deduplicate-entries-in-cdi-spec' into 'main'

Add transform to deduplicate entities in CDI spec

See merge request nvidia/container-toolkit/container-toolkit!345

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## v1.13.0-rc.3
 
+* Generate a simplified CDI specification by default. This means that entities in the common edits in a spec are not included in device definitions.
+* Add transformers to deduplicate and simplify CDI specifications.
 * Fix the generation of CDI specifications for management containers when the driver libraries are not in the LDCache.
 * Prefer /run over /var/run when locating nvidia-persistenced and nvidia-fabricmanager sockets.
 * Only initialize NVML for modes that require it when runing `nvidia-ctk cdi generate`

pkg/nvcdi/spec/builder.go

@@ -19,6 +19,7 @@ package spec
 import (
 	"fmt"
 
+	"github.com/NVIDIA/nvidia-container-toolkit/pkg/nvcdi/transform"
 	"github.com/container-orchestrated-devices/container-device-interface/pkg/cdi"
 	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
 )
@@ -31,6 +32,7 @@ type builder struct {
 	deviceSpecs []specs.Device
 	edits       specs.ContainerEdits
 	format      string
+	noSimplify  bool
 }
 
 // newBuilder creates a new spec builder with the supplied options
@@ -76,6 +78,13 @@ func (o *builder) Build() (*spec, error) {
 		raw.Version = minVersion
 	}
 
+	if !o.noSimplify {
+		err := transform.NewSimplifier().Transform(raw)
+		if err != nil {
+			return nil, fmt.Errorf("failed to simplify spec: %v", err)
+		}
+	}
+
 	s := spec{
 		Spec:   raw,
 		format: o.format,
@@ -128,3 +137,10 @@ func WithFormat(format string) Option {
 		o.format = format
 	}
 }
+
+// WithNoSimplify sets whether the spec must be simplified
+func WithNoSimplify(noSimplify bool) Option {
+	return func(o *builder) {
+		o.noSimplify = noSimplify
+	}
+}

pkg/nvcdi/transform/deduplicate.go

@@ -0,0 +1,151 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 transform
+
+import (
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+)
+
+type dedupe struct{}
+
+var _ Transformer = (*dedupe)(nil)
+
+// NewDedupe creates a transformer that deduplicates container edits.
+func NewDedupe() (Transformer, error) {
+	return &dedupe{}, nil
+}
+
+// Transform removes duplicate entris from devices and common container edits.
+func (d dedupe) Transform(spec *specs.Spec) error {
+	if spec == nil {
+		return nil
+	}
+	if err := d.transformEdits(&spec.ContainerEdits); err != nil {
+		return err
+	}
+	var updatedDevices []specs.Device
+	for _, device := range spec.Devices {
+		if err := d.transformEdits(&device.ContainerEdits); err != nil {
+			return err
+		}
+		updatedDevices = append(updatedDevices, device)
+	}
+	spec.Devices = updatedDevices
+	return nil
+}
+
+func (d dedupe) transformEdits(edits *specs.ContainerEdits) error {
+	deviceNodes, err := d.deduplicateDeviceNodes(edits.DeviceNodes)
+	if err != nil {
+		return err
+	}
+	edits.DeviceNodes = deviceNodes
+
+	envs, err := d.deduplicateEnvs(edits.Env)
+	if err != nil {
+		return err
+	}
+	edits.Env = envs
+
+	hooks, err := d.deduplicateHooks(edits.Hooks)
+	if err != nil {
+		return err
+	}
+	edits.Hooks = hooks
+
+	mounts, err := d.deduplicateMounts(edits.Mounts)
+	if err != nil {
+		return err
+	}
+	edits.Mounts = mounts
+
+	return nil
+}
+
+func (d dedupe) deduplicateDeviceNodes(entities []*specs.DeviceNode) ([]*specs.DeviceNode, error) {
+	seen := make(map[string]bool)
+	var deviceNodes []*specs.DeviceNode
+	for _, e := range entities {
+		if e == nil {
+			continue
+		}
+		id, err := deviceNode(*e).id()
+		if err != nil {
+			return nil, err
+		}
+		if seen[id] {
+			continue
+		}
+		seen[id] = true
+		deviceNodes = append(deviceNodes, e)
+	}
+	return deviceNodes, nil
+}
+
+func (d dedupe) deduplicateEnvs(entities []string) ([]string, error) {
+	seen := make(map[string]bool)
+	var envs []string
+	for _, e := range entities {
+		id := e
+		if seen[id] {
+			continue
+		}
+		seen[id] = true
+		envs = append(envs, e)
+	}
+	return envs, nil
+}
+
+func (d dedupe) deduplicateHooks(entities []*specs.Hook) ([]*specs.Hook, error) {
+	seen := make(map[string]bool)
+	var hooks []*specs.Hook
+	for _, e := range entities {
+		if e == nil {
+			continue
+		}
+		id, err := hook(*e).id()
+		if err != nil {
+			return nil, err
+		}
+		if seen[id] {
+			continue
+		}
+		seen[id] = true
+		hooks = append(hooks, e)
+	}
+	return hooks, nil
+}
+
+func (d dedupe) deduplicateMounts(entities []*specs.Mount) ([]*specs.Mount, error) {
+	seen := make(map[string]bool)
+	var mounts []*specs.Mount
+	for _, e := range entities {
+		if e == nil {
+			continue
+		}
+		id, err := mount(*e).id()
+		if err != nil {
+			return nil, err
+		}
+		if seen[id] {
+			continue
+		}
+		seen[id] = true
+		mounts = append(mounts, e)
+	}
+	return mounts, nil
+}

pkg/nvcdi/transform/deduplicate_test.go

@@ -0,0 +1,250 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 transform
+
+import (
+	"testing"
+
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDeduplicate(t *testing.T) {
+	testCases := []struct {
+		description   string
+		spec          *specs.Spec
+		expectedError error
+		expectedSpec  *specs.Spec
+	}{
+		{
+			description: "nil spec",
+		},
+		{
+			description: "duplicate deviceNode is removed",
+			spec: &specs.Spec{
+				ContainerEdits: specs.ContainerEdits{
+					DeviceNodes: []*specs.DeviceNode{
+						{
+							Path: "/dev/gpu0",
+						},
+						{
+							Path: "/dev/gpu0",
+						},
+					},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				ContainerEdits: specs.ContainerEdits{
+					DeviceNodes: []*specs.DeviceNode{
+						{
+							Path: "/dev/gpu0",
+						},
+					},
+				},
+			},
+		},
+		{
+			description: "duplicate deviceNode is remved from device edits",
+			spec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							DeviceNodes: []*specs.DeviceNode{
+								{
+									Path: "/dev/gpu0",
+								},
+								{
+									Path: "/dev/gpu0",
+								},
+							},
+						},
+					},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							DeviceNodes: []*specs.DeviceNode{
+								{
+									Path: "/dev/gpu0",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			description: "duplicate hook is removed",
+			spec: &specs.Spec{
+				ContainerEdits: specs.ContainerEdits{
+					Hooks: []*specs.Hook{
+						{
+							HookName: "createContainer",
+							Path:     "/usr/bin/nvidia-ctk",
+							Args:     []string{"nvidia-ctk", "hook", "chmod", "--mode", "755", "--path", "/dev/dri"},
+						},
+						{
+							HookName: "createContainer",
+							Path:     "/usr/bin/nvidia-ctk",
+							Args:     []string{"nvidia-ctk", "hook", "chmod", "--mode", "755", "--path", "/dev/dri"},
+						},
+					},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				ContainerEdits: specs.ContainerEdits{
+					Hooks: []*specs.Hook{
+						{
+							HookName: "createContainer",
+							Path:     "/usr/bin/nvidia-ctk",
+							Args:     []string{"nvidia-ctk", "hook", "chmod", "--mode", "755", "--path", "/dev/dri"},
+						},
+					},
+				},
+			},
+		},
+		{
+			description: "duplicate mount is removed",
+			spec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Mounts: []*specs.Mount{
+								{
+									HostPath:      "/host/mount2",
+									ContainerPath: "/mount2",
+								},
+								{
+									HostPath:      "/host/mount2",
+									ContainerPath: "/mount2",
+								},
+								{
+									HostPath:      "/host/mount1",
+									ContainerPath: "/mount1",
+								},
+							},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Mounts: []*specs.Mount{
+						{
+							HostPath:      "/host/mount1",
+							ContainerPath: "/mount1",
+							Options:       []string{"bind", "ro"},
+							Type:          "tmpfs",
+						},
+						{
+							HostPath:      "/host/mount1",
+							ContainerPath: "/mount1",
+							Options:       []string{"bind", "ro"},
+							Type:          "tmpfs",
+						},
+						{
+							HostPath:      "/host/mount1",
+							ContainerPath: "/mount1",
+							Options:       []string{"bind", "ro"},
+						},
+					},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Mounts: []*specs.Mount{
+								{
+									HostPath:      "/host/mount2",
+									ContainerPath: "/mount2",
+								},
+								{
+									HostPath:      "/host/mount1",
+									ContainerPath: "/mount1",
+								},
+							},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Mounts: []*specs.Mount{
+						{
+							HostPath:      "/host/mount1",
+							ContainerPath: "/mount1",
+							Options:       []string{"bind", "ro"},
+							Type:          "tmpfs",
+						},
+						{
+							HostPath:      "/host/mount1",
+							ContainerPath: "/mount1",
+							Options:       []string{"bind", "ro"},
+						},
+					},
+				},
+			},
+		},
+		{
+			description: "duplicate env is removed",
+			spec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Env: []string{"ENV1=VAL1", "ENV1=VAL1", "ENV2=ONE_VALUE", "ENV2=ANOTHER_VALUE"},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Env: []string{"ENV1=VAL1", "ENV1=VAL1", "ENV2=ONE_VALUE", "ENV2=ANOTHER_VALUE"},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Env: []string{"ENV1=VAL1", "ENV2=ONE_VALUE", "ENV2=ANOTHER_VALUE"},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Env: []string{"ENV1=VAL1", "ENV2=ONE_VALUE", "ENV2=ANOTHER_VALUE"},
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			d := dedupe{}
+
+			err := d.Transform(tc.spec)
+			if tc.expectedError != nil {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+
+			require.EqualValues(t, tc.expectedSpec, tc.spec)
+		})
+	}
+}

pkg/nvcdi/transform/edits.go

@@ -0,0 +1,166 @@
+/*
+*
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 transform
+
+import (
+	"encoding/json"
+
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+)
+
+type containerEdits specs.ContainerEdits
+
+// IsEmpty returns true if the edits are empty.
+func (e containerEdits) IsEmpty() bool {
+	// Devices with empty edits are invalid
+	if len(e.DeviceNodes) > 0 {
+		return false
+	}
+	if len(e.Env) > 0 {
+		return false
+	}
+	if len(e.Hooks) > 0 {
+		return false
+	}
+	if len(e.Mounts) > 0 {
+		return false
+	}
+
+	return true
+}
+
+func (e *containerEdits) getEntityIds() ([]string, error) {
+	if e == nil {
+		return nil, nil
+	}
+	uniqueIDs := make(map[string]bool)
+
+	deviceNodes, err := e.getDeviceNodeIDs()
+	if err != nil {
+		return nil, err
+	}
+	for k := range deviceNodes {
+		uniqueIDs[k] = true
+	}
+
+	envs, err := e.getEnvIDs()
+	if err != nil {
+		return nil, err
+	}
+	for k := range envs {
+		uniqueIDs[k] = true
+	}
+
+	hooks, err := e.getHookIDs()
+	if err != nil {
+		return nil, err
+	}
+	for k := range hooks {
+		uniqueIDs[k] = true
+	}
+
+	mounts, err := e.getMountIDs()
+	if err != nil {
+		return nil, err
+	}
+	for k := range mounts {
+		uniqueIDs[k] = true
+	}
+
+	var ids []string
+	for k := range uniqueIDs {
+		ids = append(ids, k)
+	}
+
+	return ids, nil
+}
+
+func (e *containerEdits) getDeviceNodeIDs() (map[string]bool, error) {
+	deviceIDs := make(map[string]bool)
+	for _, entity := range e.DeviceNodes {
+		id, err := deviceNode(*entity).id()
+		if err != nil {
+			return nil, err
+		}
+		deviceIDs[id] = true
+	}
+	return deviceIDs, nil
+}
+
+func (e *containerEdits) getEnvIDs() (map[string]bool, error) {
+	envIDs := make(map[string]bool)
+	for _, entity := range e.Env {
+		id, err := env(entity).id()
+		if err != nil {
+			return nil, err
+		}
+		envIDs[id] = true
+	}
+	return envIDs, nil
+}
+
+func (e *containerEdits) getHookIDs() (map[string]bool, error) {
+	hookIDs := make(map[string]bool)
+	for _, entity := range e.Hooks {
+		id, err := hook(*entity).id()
+		if err != nil {
+			return nil, err
+		}
+		hookIDs[id] = true
+	}
+	return hookIDs, nil
+}
+
+func (e *containerEdits) getMountIDs() (map[string]bool, error) {
+	mountIDs := make(map[string]bool)
+	for _, entity := range e.Mounts {
+		id, err := mount(*entity).id()
+		if err != nil {
+			return nil, err
+		}
+		mountIDs[id] = true
+	}
+	return mountIDs, nil
+}
+
+type deviceNode specs.DeviceNode
+
+func (dn deviceNode) id() (string, error) {
+	b, err := json.Marshal(dn)
+	return string(b), err
+}
+
+type env string
+
+func (e env) id() (string, error) {
+	return string(e), nil
+}
+
+type mount specs.Mount
+
+func (m mount) id() (string, error) {
+	b, err := json.Marshal(m)
+	return string(b), err
+}
+
+type hook specs.Hook
+
+func (m hook) id() (string, error) {
+	b, err := json.Marshal(m)
+	return string(b), err
+}

pkg/nvcdi/transform/remove.go

@@ -0,0 +1,105 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 transform
+
+import (
+	"fmt"
+
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+)
+
+type remove map[string]bool
+
+func newRemover(ids ...string) Transformer {
+	r := make(remove)
+	for _, id := range ids {
+		r[id] = true
+	}
+	return r
+}
+
+// Transform remove the specified entities from the spec.
+func (r remove) Transform(spec *specs.Spec) error {
+	if spec == nil {
+		return nil
+	}
+
+	for _, device := range spec.Devices {
+		if err := r.transformEdits(&device.ContainerEdits); err != nil {
+			return fmt.Errorf("failed to remove edits from device %q: %w", device.Name, err)
+		}
+	}
+
+	return r.transformEdits(&spec.ContainerEdits)
+}
+
+func (r remove) transformEdits(edits *specs.ContainerEdits) error {
+	if edits == nil {
+		return nil
+	}
+
+	var deviceNodes []*specs.DeviceNode
+	for _, entity := range edits.DeviceNodes {
+		id, err := deviceNode(*entity).id()
+		if err != nil {
+			return err
+		}
+		if r[id] {
+			continue
+		}
+		deviceNodes = append(deviceNodes, entity)
+	}
+	edits.DeviceNodes = deviceNodes
+
+	var envs []string
+	for _, entity := range edits.Env {
+		id := entity
+		if r[id] {
+			continue
+		}
+		envs = append(envs, entity)
+	}
+	edits.Env = envs
+
+	var hooks []*specs.Hook
+	for _, entity := range edits.Hooks {
+		id, err := hook(*entity).id()
+		if err != nil {
+			return err
+		}
+		if r[id] {
+			continue
+		}
+		hooks = append(hooks, entity)
+	}
+	edits.Hooks = hooks
+
+	var mounts []*specs.Mount
+	for _, entity := range edits.Mounts {
+		id, err := mount(*entity).id()
+		if err != nil {
+			return err
+		}
+		if r[id] {
+			continue
+		}
+		mounts = append(mounts, entity)
+	}
+	edits.Mounts = mounts
+
+	return nil
+}

pkg/nvcdi/transform/simplify.go

@@ -0,0 +1,74 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 transform
+
+import (
+	"fmt"
+
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+)
+
+type simplify struct{}
+
+var _ Transformer = (*simplify)(nil)
+
+// NewSimplifier creates a simplifier transformer.
+// This transoformer ensures that entities in the spec are deduplicated and that common edits are removed from device-specific edits.
+func NewSimplifier() Transformer {
+	return &simplify{}
+}
+
+// Transform simplifies the supplied spec.
+// Edits that are present in the common edits are removed from device-specific edits.
+func (s simplify) Transform(spec *specs.Spec) error {
+	if spec == nil {
+		return nil
+	}
+
+	dedupe := dedupe{}
+	if err := dedupe.Transform(spec); err != nil {
+		return err
+	}
+
+	commonEntityIDs, err := (*containerEdits)(&spec.ContainerEdits).getEntityIds()
+	if err != nil {
+		return err
+	}
+
+	toRemove := newRemover(commonEntityIDs...)
+	var updatedDevices []specs.Device
+	for _, device := range spec.Devices {
+		deviceAsSpec := specs.Spec{
+			ContainerEdits: device.ContainerEdits,
+		}
+		err := toRemove.Transform(&deviceAsSpec)
+		if err != nil {
+			return fmt.Errorf("failed to transform device edits: %w", err)
+		}
+
+		if !(containerEdits)(deviceAsSpec.ContainerEdits).IsEmpty() {
+			// Devices with empty edits are invalid.
+			// We only update the container edits for the device if this would
+			// result in a valid device.
+			device.ContainerEdits = deviceAsSpec.ContainerEdits
+		}
+		updatedDevices = append(updatedDevices, device)
+	}
+	spec.Devices = updatedDevices
+
+	return nil
+}

pkg/nvcdi/transform/simplify_test.go

@@ -0,0 +1,125 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 transform
+
+import (
+	"testing"
+
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSimplify(t *testing.T) {
+	testCases := []struct {
+		description   string
+		spec          *specs.Spec
+		expectedError error
+		expectedSpec  *specs.Spec
+	}{
+		{
+			description: "nil spec is a no-op",
+		},
+		{
+			description:  "empty spec is simplified",
+			spec:         &specs.Spec{},
+			expectedSpec: &specs.Spec{},
+		},
+		{
+			description: "simplify does not allow empty device",
+			spec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Env: []string{"FOO=BAR"},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Env: []string{"FOO=BAR"},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Env: []string{"FOO=BAR"},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Env: []string{"FOO=BAR"},
+				},
+			},
+		},
+		{
+			description: "simplify removes common entities",
+			spec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							Env: []string{"FOO=BAR"},
+							DeviceNodes: []*specs.DeviceNode{
+								{
+									Path: "/dev/gpu0",
+								},
+							},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Env: []string{"FOO=BAR"},
+				},
+			},
+			expectedSpec: &specs.Spec{
+				Devices: []specs.Device{
+					{
+						Name: "device0",
+						ContainerEdits: specs.ContainerEdits{
+							DeviceNodes: []*specs.DeviceNode{
+								{
+									Path: "/dev/gpu0",
+								},
+							},
+						},
+					},
+				},
+				ContainerEdits: specs.ContainerEdits{
+					Env: []string{"FOO=BAR"},
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			s := simplify{}
+
+			err := s.Transform(tc.spec)
+			if tc.expectedError != nil {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+
+			require.EqualValues(t, tc.expectedSpec, tc.spec)
+
+		})
+	}
+}