Allow device names to start with a digit

This change ensures that device names starting with a digit are
considered valid. This means that vendor.com/class=0 is a valid
fully-qualified device name.

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

Author: elezar

pkg/cdi/qualified-device.go

@@ -172,8 +172,11 @@ func ValidateDeviceName(name string) error {
 	if name == "" {
 		return errors.Errorf("invalid (empty) device name")
 	}
-	if !isLetter(rune(name[0])) {
-		return errors.Errorf("invalid name %q, should start with letter", name)
+	if !isAlphaNumeric(rune(name[0])) {
+		return errors.Errorf("invalid class %q, should start with a letter or digit", name)
+	}
+	if len(name) == 1 {
+		return nil
 	}
 	for _, c := range string(name[1 : len(name)-1]) {
 		switch {

pkg/cdi/qualified-device_test.go

@@ -40,6 +40,13 @@ func TestQualifiedName(t *testing.T) {
 			name:        "dev",
 			isQualified: true,
 		},
+		{
+			device:      "vendor.com/class=0",
+			vendor:      "vendor.com",
+			class:       "class",
+			name:        "0",
+			isQualified: true,
+		},
 		{
 			device:      "vendor1.com/class1=dev1",
 			vendor:      "vendor1.com",