Create .so symlinks for driver libraries in container

This change adds an opt-in feature for creating .so symlinks to
all injected driver files in a contianer.

If features.dot-so-symlinks = true is set in the config.toml, the creation
of symlinks for driver files is enabled. This can also be triggered on a
per-container basis using the envvar NVIDIA_DOT_SO_SYMLINKS=enabled.

Signed-off-by: Evan Lezar <[email protected]>

Author: elezar

CHANGELOG.md

@@ -1,5 +1,7 @@
 # NVIDIA Container Toolkit Changelog
 
+* Add a hook to create `.so` symlinks for driver libraries in a container.
+
 ## v1.15.0-rc.4
 * Add a `--spec-dir` option to the `nvidia-ctk cdi generate` command. This allows specs outside of `/etc/cdi` and `/var/run/cdi` to be processed.
 * Add support for extracting device major number from `/proc/devices` if `nvidia` is used as a device name over `nvidia-frontend`.

cmd/nvidia-ctk/hook/create-dot-so-symlinks/create-dot-so-symlinks.go

@@ -0,0 +1,115 @@
+/**
+# 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 dotsosymlinks
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/urfave/cli/v2"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/logger"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
+)
+
+type command struct {
+	logger logger.Interface
+}
+
+type config struct {
+	containerSpec string
+	driverVersion string
+}
+
+// NewCommand constructs a hook command with the specified logger
+func NewCommand(logger logger.Interface) *cli.Command {
+	c := command{
+		logger: logger,
+	}
+	return c.build()
+}
+
+// build
+func (m command) build() *cli.Command {
+	cfg := config{}
+
+	// Create the '' command
+	c := cli.Command{
+		Name:  "create-dot-so-symlinks",
+		Usage: "A hook to create .so symlinks in the container.",
+		Action: func(c *cli.Context) error {
+			return m.run(c, &cfg)
+		},
+	}
+
+	c.Flags = []cli.Flag{
+		&cli.StringFlag{
+			Name:        "container-spec",
+			Usage:       "Specify the path to the OCI container spec. If empty or '-' the spec will be read from STDIN",
+			Destination: &cfg.containerSpec,
+		},
+		&cli.StringFlag{
+			Name:        "driver-version",
+			Usage:       "specify the driver version for which the symlinks are to be created. This assumes driver libraries have the .so.`VERSION` suffix.",
+			Destination: &cfg.driverVersion,
+			Required:    true,
+		},
+	}
+
+	return &c
+}
+
+func (m command) run(c *cli.Context, cfg *config) error {
+	s, err := oci.LoadContainerState(cfg.containerSpec)
+	if err != nil {
+		return fmt.Errorf("failed to load container state: %v", err)
+	}
+
+	containerRoot, err := s.GetContainerRoot()
+	if err != nil {
+		return fmt.Errorf("failed to determined container root: %v", err)
+	}
+
+	locator := lookup.NewLibraryLocator(
+		lookup.WithLogger(m.logger),
+		lookup.WithRoot(containerRoot),
+		lookup.WithOptional(true),
+	)
+	libs, err := locator.Locate("*.so." + cfg.driverVersion)
+	if err != nil {
+		return fmt.Errorf("failed to locate libraries for driver version %v: %v", cfg.driverVersion, err)
+	}
+
+	for _, lib := range libs {
+		if !strings.HasSuffix(lib, ".so."+cfg.driverVersion) {
+			continue
+		}
+		libSoPath := strings.TrimSuffix(lib, "."+cfg.driverVersion)
+		libSoXPaths, err := filepath.Glob(libSoPath + ".[0-9]")
+		if len(libSoXPaths) != 1 || err != nil {
+			continue
+		}
+		err = os.Symlink(filepath.Base(libSoXPaths[0]), libSoPath)
+		if err != nil {
+			continue
+		}
+	}
+	return nil
+}

cmd/nvidia-ctk/hook/hook.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/urfave/cli/v2"
 
+	createdotsosymlinks "github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/hook/create-dot-so-symlinks"
 	symlinks "github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/hook/create-symlinks"
 	ldcache "github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/hook/update-ldcache"
 )
@@ -50,6 +51,7 @@ func (m hookCommand) build() *cli.Command {
 		ldcache.NewCommand(m.logger),
 		symlinks.NewCommand(m.logger),
 		chmod.NewCommand(m.logger),
+		createdotsosymlinks.NewCommand(m.logger),
 	}
 
 	return &hook

internal/config/features.go

@@ -19,10 +19,11 @@ package config
 type featureName string
 
 const (
-	FeatureGDS      = featureName("gds")
-	FeatureMOFED    = featureName("mofed")
-	FeatureNVSWITCH = featureName("nvswitch")
-	FeatureGDRCopy  = featureName("gdrcopy")
+	FeatureGDS           = featureName("gds")
+	FeatureMOFED         = featureName("mofed")
+	FeatureNVSWITCH      = featureName("nvswitch")
+	FeatureGDRCopy       = featureName("gdrcopy")
+	FeatureDotSoSymlinks = featureName("dot-so-symlinks")
 )
 
 // features specifies a set of named features.
@@ -31,6 +32,9 @@ type features struct {
 	MOFED    *feature `toml:"mofed,omitempty"`
 	NVSWITCH *feature `toml:"nvswitch,omitempty"`
 	GDRCopy  *feature `toml:"gdrcopy,omitempty"`
+	// DotSoSymlinks allows for the creation of .so symlinks to .so.1 driver
+	// files to be opted in to.
+	DotSoSymlinks *feature `toml:"dot-so-symlinks,omitempty"`
 }
 
 type feature bool
@@ -40,10 +44,11 @@ type feature bool
 // variables can also be supplied.
 func (fs features) IsEnabled(n featureName, in ...getenver) bool {
 	featureEnvvars := map[featureName]string{
-		FeatureGDS:      "NVIDIA_GDS",
-		FeatureMOFED:    "NVIDIA_MOFED",
-		FeatureNVSWITCH: "NVIDIA_NVSWITCH",
-		FeatureGDRCopy:  "NVIDIA_GDRCOPY",
+		FeatureGDS:           "NVIDIA_GDS",
+		FeatureMOFED:         "NVIDIA_MOFED",
+		FeatureNVSWITCH:      "NVIDIA_NVSWITCH",
+		FeatureGDRCopy:       "NVIDIA_GDRCOPY",
+		FeatureDotSoSymlinks: "NVIDIA_DOT_SO_SYMLINKS",
 	}
 
 	envvar := featureEnvvars[n]
@@ -56,6 +61,8 @@ func (fs features) IsEnabled(n featureName, in ...getenver) bool {
 		return fs.NVSWITCH.isEnabled(envvar, in...)
 	case FeatureGDRCopy:
 		return fs.GDRCopy.isEnabled(envvar, in...)
+	case FeatureDotSoSymlinks:
+		return fs.DotSoSymlinks.isEnabled(envvar, in...)
 	default:
 		return false
 	}

internal/discover/dot_so_symlinks.go

@@ -0,0 +1,27 @@
+/**
+# Copyright 2024 NVIDIA CORPORATION
+#
+# 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 discover
+
+// NewDotSoSymlinksDiscoverer creates a discoverer that generates a hook to create .so symlinks in
+// a container.
+func NewDotSoSymlinksDiscoverer(nvidiaCTKPath string, version string) Discover {
+	return CreateNvidiaCTKHook(
+		nvidiaCTKPath,
+		"create-dot-so-symlinks",
+		"--driver-version", version,
+	)
+}

internal/discover/graphics.go

@@ -27,7 +27,6 @@ import (
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/info/proc"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/logger"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup"
-	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup/cuda"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup/root"
 )
 
@@ -252,20 +251,16 @@ func optionalXorgDiscoverer(logger logger.Interface, driver *root.Driver, nvidia
 }
 
 func newXorgDiscoverer(logger logger.Interface, driver *root.Driver, nvidiaCTKPath string) (Discover, error) {
-	libCudaPaths, err := cuda.New(
-		driver.Libraries(),
-	).Locate(".*.*")
+	libRoot, err := driver.LibraryRoot()
 	if err != nil {
-		return nil, fmt.Errorf("failed to locate libcuda.so: %v", err)
+		return nil, fmt.Errorf("failed to determine driver library root: %w", err)
 	}
-	libcudaPath := libCudaPaths[0]
 
-	version := strings.TrimPrefix(filepath.Base(libcudaPath), "libcuda.so.")
-	if version == "" {
-		return nil, fmt.Errorf("failed to determine libcuda.so version from path: %q", libcudaPath)
+	version, err := driver.Version()
+	if err != nil {
+		return nil, fmt.Errorf("failed to determine driver version: %w", err)
 	}
 
-	libRoot := filepath.Dir(libcudaPath)
 	xorgLibs := NewMounts(
 		logger,
 		lookup.NewFileLocator(

internal/lookup/root/options.go

@@ -43,3 +43,9 @@ func WithConfigSearchPaths(paths ...string) Option {
 		d.configSearchPaths = paths
 	}
 }
+
+func WithVersion(version string) Option {
+	return func(d *Driver) {
+		d.version = version
+	}
+}

internal/lookup/root/root.go

@@ -17,22 +17,30 @@
 package root
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
+	"sync"
 
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/logger"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup"
 )
 
 // Driver represents a filesystem in which a set of drivers or devices is defined.
 type Driver struct {
+	sync.Mutex
 	logger logger.Interface
 	// Root represents the root from the perspective of the driver libraries and binaries.
 	Root string
 	// librarySearchPaths specifies explicit search paths for discovering libraries.
 	librarySearchPaths []string
 	// configSearchPaths specified explicit search paths for discovering driver config files.
 	configSearchPaths []string
+	// version stores the driver version. This can be specified at construction or cached on subsequent calls.
+	version string
+	// libraryRoot stores the absolute path where the driver libraries (libcuda.so.<VERSION>) can be found.
+	libraryRoot string
 }
 
 // New creates a new Driver root using the specified options.
@@ -80,6 +88,62 @@ func (r *Driver) configSearchOptions() []lookup.Option {
 	}
 }
 
+// Version returns the driver version as a string.
+func (r *Driver) Version() (string, error) {
+	r.Lock()
+	defer r.Unlock()
+	if r.version != "" {
+		return r.version, nil
+	}
+
+	libcudaPath, err := r.libcudaPath()
+	if err != nil {
+		return "", fmt.Errorf("failed to locate libcuda.so: %v", err)
+	}
+
+	version := strings.TrimPrefix(filepath.Base(libcudaPath), "libcuda.so.")
+	if version == "" {
+		return "", fmt.Errorf("failed to determine libcuda.so version from path: %q", libcudaPath)
+	}
+
+	r.version = version
+	return r.version, nil
+}
+
+// LibraryRoot returns the folder in which the driver libraries can be found.
+func (r *Driver) LibraryRoot() (string, error) {
+	r.Lock()
+	defer r.Unlock()
+	if r.libraryRoot != "" {
+		return r.libraryRoot, nil
+	}
+
+	libcudaPath, err := r.libcudaPath()
+	if err != nil {
+		return "", fmt.Errorf("failed to locate libcuda.so: %v", err)
+	}
+
+	r.libraryRoot = filepath.Dir(libcudaPath)
+	return r.libraryRoot, nil
+}
+
+// libcudaPath returns the path to libcuda.so.*.* in the driver root.
+func (r *Driver) libcudaPath() (string, error) {
+	pattern := "libcuda.so.*.*"
+
+	locator := r.Libraries()
+	paths, err := locator.Locate(pattern)
+	if err != nil {
+		return "", fmt.Errorf("failed to locate %v: %v", pattern, err)
+	}
+
+	libcudaPath := paths[0]
+	if len(paths) > 1 {
+		r.logger.Warningf("Selecting %v out of multiple libcuda.so paths.", libcudaPath, paths)
+	}
+	return libcudaPath, nil
+}
+
 // normalizeSearchPaths takes a list of paths and normalized these.
 // Each of the elements in the list is expanded if it is a path list and the
 // resultant list is returned.