Add Discoverer to create a single symlink

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

internal/discover/hooks.go

@@ -29,12 +29,47 @@ const (
 	nvidiaCTKDefaultFilePath = "/usr/bin/nvidia-ctk"
 )
 
+var _ Discover = (*Hook)(nil)
+
+// Devices returns an empty list of devices for a Hook discoverer.
+func (h Hook) Devices() ([]Device, error) {
+	return nil, nil
+}
+
+// Mounts returns an empty list of mounts for a Hook discoverer.
+func (h Hook) Mounts() ([]Mount, error) {
+	return nil, nil
+}
+
+// Hooks allows the Hook type to also implement the Discoverer interface.
+// It returns a single hook
+func (h Hook) Hooks() ([]Hook, error) {
+	return []Hook{h}, nil
+}
+
+// CreateCreateSymlinkHook creates a hook which creates a symlink from link -> target.
+func CreateCreateSymlinkHook(nvidiaCTKPath string, links []string) Discover {
+	if len(links) == 0 {
+		return None{}
+	}
+
+	var args []string
+	for _, link := range links {
+		args = append(args, "--link", link)
+	}
+	return CreateNvidiaCTKHook(
+		nvidiaCTKPath,
+		"create-symlinks",
+		args...,
+	)
+}
+
 // CreateNvidiaCTKHook creates a hook which invokes the NVIDIA Container CLI hook subcommand.
-func CreateNvidiaCTKHook(executable string, hookName string, additionalArgs ...string) Hook {
+func CreateNvidiaCTKHook(nvidiaCTKPath string, hookName string, additionalArgs ...string) Hook {
 	return Hook{
 		Lifecycle: cdi.CreateContainerHook,
-		Path:      executable,
-		Args:      append([]string{filepath.Base(executable), "hook", hookName}, additionalArgs...),
+		Path:      nvidiaCTKPath,
+		Args:      append([]string{filepath.Base(nvidiaCTKPath), "hook", hookName}, additionalArgs...),
 	}
 }