apply comments

pkg/util/validation.go

@@ -20,7 +20,11 @@ import (
 	"regexp"
 )
 
-const LabelValueFmt string = "[-A-Za-z0-9_.]*"
+const kubeChar string = "[A-Za-z0-9]"
+const extendedKubeChar string = "[-A-Za-z0-9_.]"
+const qualifiedToken string = "(" + kubeChar + extendedKubeChar + "*)?" + kubeChar
+
+const LabelValueFmt string = "((" + kubeChar + extendedKubeChar + "*)?" + kubeChar + ")?"
 
 var labelValueRegexp = regexp.MustCompile("^" + LabelValueFmt + "$")
 
@@ -35,10 +39,7 @@ func IsValidAnnotationValue(value string) bool {
 	return true
 }
 
-const kubeToken string = "[A-Za-z0-9]"
-const extendedKubeToken string = "[-A-Za-z0-9_.]"
-const qualifiedNamePiece string = "(" + kubeToken + extendedKubeToken + "*)?" + kubeToken
-const QualifiedNameFmt string = "(" + qualifiedNamePiece + "/)?" + qualifiedNamePiece
+const QualifiedNameFmt string = "(" + qualifiedToken + "/)?" + qualifiedToken
 
 var qualifiedNameRegexp = regexp.MustCompile("^" + QualifiedNameFmt + "$")
 

pkg/util/validation_test.go

@@ -196,12 +196,9 @@ func TestIsValidLabelValue(t *testing.T) {
 		"now-with-dashes",
 		"1-starts-with-num",
 		"end-with-num-1",
-		"-starts-with-dash",
-		"ends-with-dash-",
-		".starts.with.dot",
-		"ends.with.dot.",
 		"1234",                  // only num
 		strings.Repeat("a", 63), // to the limit
+		"", // empty value
 	}
 	for i := range successCases {
 		if !IsValidLabelValue(successCases[i]) {
@@ -213,6 +210,10 @@ func TestIsValidLabelValue(t *testing.T) {
 		"nospecialchars%^=@",
 		"Tama-nui-te-rā.is.Māori.sun",
 		"\\backslashes\\are\\bad",
+		"-starts-with-dash",
+		"ends-with-dash-",
+		".starts.with.dot",
+		"ends.with.dot.",
 		strings.Repeat("a", 64), // over the limit
 	}
 	for i := range errorCases {