Add cdi mode to NVIDIA Container Runtime

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

cmd/nvidia-container-runtime/runtime_factory.go

@@ -91,6 +91,8 @@ func newModeModifier(logger *logrus.Logger, cfg *config.Config, ociSpec oci.Spec
 		return modifier.NewStableRuntimeModifier(logger), nil
 	case "csv":
 		return modifier.NewCSVModifier(logger, cfg, ociSpec)
+	case "cdi":
+		return modifier.NewCDIModifier(logger, cfg, ociSpec)
 	}
 
 	return nil, fmt.Errorf("invalid runtime mode: %v", cfg.NVIDIAContainerRuntimeConfig.Mode)

internal/modifier/cdi.go

@@ -0,0 +1,100 @@
+/**
+# 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 modifier
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config/image"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
+	cdi "github.com/container-orchestrated-devices/container-device-interface/pkg/cdi"
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/sirupsen/logrus"
+)
+
+type cdiModifier struct {
+	logger  *logrus.Logger
+	devices []string
+}
+
+// NewCDIModifier creates an OCI spec modifier that determines the modifications to make based on the
+// CDI specifications available on the system. The NVIDIA_VISIBLE_DEVICES enviroment variable is
+// used to select the devices to include.
+func NewCDIModifier(logger *logrus.Logger, cfg *config.Config, ociSpec oci.Spec) (oci.SpecModifier, error) {
+	rawSpec, err := ociSpec.Load()
+	if err != nil {
+		return nil, fmt.Errorf("failed to load OCI spec: %v", err)
+	}
+
+	image, err := image.NewCUDAImageFromSpec(rawSpec)
+	if err != nil {
+		return nil, err
+	}
+
+	devices := image.DevicesFromEnvvars(visibleDevicesEnvvar)
+	if len(devices) == 0 {
+		logger.Debugf("No modification required; no devices requested")
+		return nil, nil
+	}
+
+	var qualifiedDevices []string
+	for _, name := range devices {
+		if !cdi.IsQualifiedName(name) {
+			name = cdi.QualifiedName("nvidia.com", "gpu", name)
+		}
+		qualifiedDevices = append(qualifiedDevices, name)
+	}
+
+	m := cdiModifier{
+		logger:  logger,
+		devices: qualifiedDevices,
+	}
+
+	return m, nil
+}
+
+// Modify loads the CDI registry and injects the specified CDI devices into the OCI runtime specification.
+func (m cdiModifier) Modify(spec *specs.Spec) error {
+	registry := cdi.GetRegistry(
+		cdi.WithAutoRefresh(false),
+	)
+	if errs := registry.GetErrors(); len(errs) > 0 {
+		m.logger.Debugf("The following errors were triggered when creating the CDI registry: %v", errs)
+	}
+
+	devices := m.devices
+	for _, d := range devices {
+		if d == "nvidia.com/gpu=all" {
+			devices = []string{}
+			for _, candidate := range registry.DeviceDB().ListDevices() {
+				if strings.HasPrefix(candidate, "nvidia.com/gpu=") {
+					devices = append(devices, candidate)
+				}
+			}
+			break
+		}
+	}
+
+	_, err := registry.InjectDevices(spec, devices...)
+	if err != nil {
+		return fmt.Errorf("failed to inject CDI devices: %v", err)
+	}
+
+	return nil
+}