Add nvidia-ctk cdi transform root command

Signed-off-by: Evan Lezar <elezar@nvidia.com>

cmd/nvidia-ctk/cdi/cdi.go

@@ -18,6 +18,7 @@ package cdi
 
 import (
 	"github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/cdi/generate"
+	"github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/cdi/transform"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
 )
@@ -44,6 +45,7 @@ func (m command) build() *cli.Command {
 
 	hook.Subcommands = []*cli.Command{
 		generate.NewCommand(m.logger),
+		transform.NewCommand(m.logger),
 	}
 
 	return &hook

cmd/nvidia-ctk/cdi/transform/root/root.go

@@ -0,0 +1,104 @@
+/**
+# Copyright (c) 2022, 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 root
+
+import (
+	"fmt"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/pkg/nvcdi/spec"
+	"github.com/NVIDIA/nvidia-container-toolkit/pkg/nvcdi/transform"
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v2"
+)
+
+type loadSaver interface {
+	Load() (spec.Interface, error)
+	Save(spec.Interface) error
+}
+
+type command struct {
+	logger *logrus.Logger
+
+	handler loadSaver
+}
+
+type config struct {
+	from string
+	to   string
+}
+
+// NewCommand constructs a generate-cdi command with the specified logger
+func NewCommand(logger *logrus.Logger, specHandler loadSaver) *cli.Command {
+	c := command{
+		logger:  logger,
+		handler: specHandler,
+	}
+	return c.build()
+}
+
+// build creates the CLI command
+func (m command) build() *cli.Command {
+	cfg := config{}
+
+	c := cli.Command{
+		Name:  "root",
+		Usage: "Apply a root transform to a CDI specification",
+		Before: func(c *cli.Context) error {
+			return m.validateFlags(c, &cfg)
+		},
+		Action: func(c *cli.Context) error {
+			return m.run(c, &cfg)
+		},
+	}
+
+	c.Flags = []cli.Flag{
+		&cli.StringFlag{
+			Name:        "from",
+			Usage:       "specify the root to be transformed",
+			Destination: &cfg.from,
+		},
+		&cli.StringFlag{
+			Name:        "to",
+			Usage:       "specify the replacement root. If this is the same as the from root, the transform is a no-op.",
+			Value:       "",
+			Destination: &cfg.to,
+		},
+	}
+
+	return &c
+}
+
+func (m command) validateFlags(c *cli.Context, cfg *config) error {
+	return nil
+}
+
+func (m command) run(c *cli.Context, cfg *config) error {
+	spec, err := m.handler.Load()
+	if err != nil {
+		return fmt.Errorf("failed to load CDI specification: %w", err)
+	}
+
+	err = transform.NewRootTransformer(
+		cfg.from,
+		cfg.to,
+	).Transform(spec.Raw())
+	if err != nil {
+		return fmt.Errorf("failed to transform CDI specification: %w", err)
+	}
+
+	return m.handler.Save(spec)
+}

cmd/nvidia-ctk/cdi/transform/transform.go

@@ -0,0 +1,128 @@
+/**
+# Copyright (c) 2022, 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"
+	"io"
+	"os"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/cdi/transform/root"
+	"github.com/NVIDIA/nvidia-container-toolkit/pkg/nvcdi/spec"
+	"github.com/container-orchestrated-devices/container-device-interface/pkg/cdi"
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v2"
+)
+
+type command struct {
+	logger *logrus.Logger
+}
+
+type options struct {
+	input  string
+	output string
+}
+
+// NewCommand constructs a command with the specified logger
+func NewCommand(logger *logrus.Logger) *cli.Command {
+	c := command{
+		logger: logger,
+	}
+	return c.build()
+}
+
+// build creates the CLI command
+func (m command) build() *cli.Command {
+	opts := options{}
+
+	c := cli.Command{
+		Name:  "transform",
+		Usage: "Apply a transform to a CDI specification",
+		Before: func(c *cli.Context) error {
+			return m.validateFlags(c, &opts)
+		},
+		Action: func(c *cli.Context) error {
+			return m.run(c, &opts)
+		},
+	}
+
+	c.Flags = []cli.Flag{
+		&cli.StringFlag{
+			Name:        "input",
+			Usage:       "Specify the file to read the CDI specification from. If this is '-' the specification is read from STDIN",
+			Value:       "-",
+			Destination: &opts.input,
+		},
+		&cli.StringFlag{
+			Name:        "output",
+			Usage:       "Specify the file to output the generated CDI specification to. If this is '' the specification is output to STDOUT",
+			Destination: &opts.output,
+		},
+	}
+
+	c.Subcommands = []*cli.Command{
+		root.NewCommand(m.logger, &opts),
+	}
+
+	return &c
+}
+
+func (m command) validateFlags(c *cli.Context, opts *options) error {
+	return nil
+}
+
+func (m command) run(c *cli.Context, cfg *options) error {
+	return nil
+}
+
+// Load lodas the input CDI specification
+func (o options) Load() (spec.Interface, error) {
+	contents, err := o.getContents()
+	if err != nil {
+		return nil, fmt.Errorf("failed to read spec contents: %v", err)
+	}
+
+	raw, err := cdi.ParseSpec(contents)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse CDI spec: %v", err)
+	}
+
+	return spec.New(
+		spec.WithRawSpec(raw),
+	)
+}
+
+func (o options) getContents() ([]byte, error) {
+	if o.input == "-" {
+		return io.ReadAll(os.Stdin)
+	}
+
+	return os.ReadFile(o.input)
+}
+
+// Save saves the CDI specification to the output file
+func (o options) Save(s spec.Interface) error {
+	if o.output == "" {
+		_, err := s.WriteTo(os.Stdout)
+		if err != nil {
+			return fmt.Errorf("failed to write CDI spec to STDOUT: %v", err)
+		}
+		return nil
+	}
+
+	return s.Save(o.output)
+}

pkg/nvcdi/spec/builder.go

@@ -41,6 +41,13 @@ func newBuilder(opts ...Option) *builder {
 	for _, opt := range opts {
 		opt(s)
 	}
+	if s.raw != nil {
+		s.noSimplify = true
+		vendor, class := cdi.ParseQualifier(s.raw.Kind)
+		s.vendor = vendor
+		s.class = class
+	}
+
 	if s.version == "" {
 		s.version = DetectMinimumVersion
 	}
@@ -60,7 +67,6 @@ func newBuilder(opts ...Option) *builder {
 // Build builds a CDI spec form the spec builder.
 func (o *builder) Build() (*spec, error) {
 	raw := o.raw
-
 	if raw == nil {
 		raw = &specs.Spec{
 			Version:        o.version,
@@ -144,3 +150,10 @@ func WithNoSimplify(noSimplify bool) Option {
 		o.noSimplify = noSimplify
 	}
 }
+
+// WithRawSpec sets the raw spec for the spec builder
+func WithRawSpec(raw *specs.Spec) Option {
+	return func(o *builder) {
+		o.raw = raw
+	}
+}