Add nvidia-ctk cdi list command

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

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Add support for updating containerd configs to the `nvidia-ctk runtime configure` command.
 * Create file in `etc/ld.so.conf.d` with permissions `644` to support non-root containers.
 * Generate CDI specification files with `644` permissions to allow rootless applications (e.g. podman)
+* Add `nvidia-ctk cdi list` command to show the known CDI devices.
 
 ## v1.13.1
 

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/list"
 	"github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/cdi/transform"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
@@ -46,6 +47,7 @@ func (m command) build() *cli.Command {
 	hook.Subcommands = []*cli.Command{
 		generate.NewCommand(m.logger),
 		transform.NewCommand(m.logger),
+		list.NewCommand(m.logger),
 	}
 
 	return &hook

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

@@ -0,0 +1,87 @@
+/**
+# 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 list
+
+import (
+	"fmt"
+
+	"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 config struct{}
+
+// NewCommand constructs a cdi list 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 {
+	cfg := config{}
+
+	// Create the command
+	c := cli.Command{
+		Name:  "list",
+		Usage: "List the available CDI devices",
+		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{}
+
+	return &c
+}
+
+func (m command) validateFlags(c *cli.Context, cfg *config) error {
+	return nil
+}
+
+func (m command) run(c *cli.Context, cfg *config) error {
+	registry, err := cdi.NewCache(
+		cdi.WithAutoRefresh(false),
+		cdi.WithSpecDirs(cdi.DefaultSpecDirs...),
+	)
+	if err != nil {
+		return fmt.Errorf("failed to create CDI cache: %v", err)
+	}
+
+	devices := registry.ListDevices()
+	if len(devices) == 0 {
+		m.logger.Info("No CDI devices found")
+		return nil
+	}
+
+	m.logger.Infof("Found %d CDI devices", len(devices))
+	for _, device := range devices {
+		fmt.Printf("%s\n", device)
+	}
+
+	return nil
+}