Rename -toolkit executable to -runtime-hook

This change renames the nvidia-container-toolkit executable
to nvidia-container-runtime-hook. Here nvidia-container-toolkit
is created as a symlink to nvidia-container-runtime-hook.

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

cmd/nvidia-container-runtime-hook/capabilities.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"log"
+	"strings"
+)
+
+const (
+	allDriverCapabilities     = DriverCapabilities("compute,compat32,graphics,utility,video,display,ngx")
+	defaultDriverCapabilities = DriverCapabilities("utility,compute")
+
+	none = DriverCapabilities("")
+	all  = DriverCapabilities("all")
+)
+
+func capabilityToCLI(cap string) string {
+	switch cap {
+	case "compute":
+		return "--compute"
+	case "compat32":
+		return "--compat32"
+	case "graphics":
+		return "--graphics"
+	case "utility":
+		return "--utility"
+	case "video":
+		return "--video"
+	case "display":
+		return "--display"
+	case "ngx":
+		return "--ngx"
+	default:
+		log.Panicln("unknown driver capability:", cap)
+	}
+	return ""
+}
+
+// DriverCapabilities is used to process the NVIDIA_DRIVER_CAPABILITIES environment
+// variable. Operations include default values, filtering, and handling meta values such as "all"
+type DriverCapabilities string
+
+// Intersection returns intersection between two sets of capabilities.
+func (d DriverCapabilities) Intersection(capabilities DriverCapabilities) DriverCapabilities {
+	if capabilities == all {
+		return d
+	}
+	if d == all {
+		return capabilities
+	}
+
+	lookup := make(map[string]bool)
+	for _, c := range d.list() {
+		lookup[c] = true
+	}
+	var found []string
+	for _, c := range capabilities.list() {
+		if lookup[c] {
+			found = append(found, c)
+		}
+	}
+
+	intersection := DriverCapabilities(strings.Join(found, ","))
+	return intersection
+}
+
+// String returns the string representation of the driver capabilities
+func (d DriverCapabilities) String() string {
+	return string(d)
+}
+
+// list returns the driver capabilities as a list
+func (d DriverCapabilities) list() []string {
+	var caps []string
+	for _, c := range strings.Split(string(d), ",") {
+		trimmed := strings.TrimSpace(c)
+		if len(trimmed) == 0 {
+			continue
+		}
+		caps = append(caps, trimmed)
+	}
+
+	return caps
+}