Custom resource definition

Co-authored-by: Mathieu Lonjaret <mathieu.lonjaret@gmail.com>

vendor/k8s.io/apimachinery/pkg/fields/selector.go

@@ -55,6 +55,21 @@ type Selector interface {
 	DeepCopySelector() Selector
 }
 
+type nothingSelector struct{}
+
+func (n nothingSelector) Matches(_ Fields) bool                                      { return false }
+func (n nothingSelector) Empty() bool                                                { return false }
+func (n nothingSelector) String() string                                             { return "" }
+func (n nothingSelector) Requirements() Requirements                                 { return nil }
+func (n nothingSelector) DeepCopySelector() Selector                                 { return n }
+func (n nothingSelector) RequiresExactMatch(field string) (value string, found bool) { return "", false }
+func (n nothingSelector) Transform(fn TransformFunc) (Selector, error)               { return n, nil }
+
+// Nothing returns a selector that matches no fields
+func Nothing() Selector {
+	return nothingSelector{}
+}
+
 // Everything returns a selector that matches all fields.
 func Everything() Selector {
 	return andTerm{}
@@ -396,7 +411,7 @@ const (
 var termOperators = []string{notEqualOperator, doubleEqualOperator, equalOperator}
 
 // splitTerm returns the lhs, operator, and rhs parsed from the given term, along with an indicator of whether the parse was successful.
-// no escaping of special characters is supported in the lhs value, so the first occurance of a recognized operator is used as the split point.
+// no escaping of special characters is supported in the lhs value, so the first occurrence of a recognized operator is used as the split point.
 // the literal rhs is returned, and the caller is responsible for applying any desired unescaping.
 func splitTerm(term string) (lhs, op, rhs string, ok bool) {
 	for i := range term {
@@ -449,6 +464,12 @@ func OneTermEqualSelector(k, v string) Selector {
 	return &hasTerm{field: k, value: v}
 }
 
+// OneTermNotEqualSelector returns an object that matches objects where one field/field does not equal one value.
+// Cannot return an error.
+func OneTermNotEqualSelector(k, v string) Selector {
+	return &notHasTerm{field: k, value: v}
+}
+
 // AndSelectors creates a selector that is the logical AND of all the given selectors
 func AndSelectors(selectors ...Selector) Selector {
 	return andTerm(selectors)