build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/k8s.io/apimachinery/pkg/util/validation/OWNERS

@@ -0,0 +1,11 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+# Disable inheritance as this is an api owners file
+options:
+  no_parent_owners: true
+approvers:
+  - api-approvers
+reviewers:
+  - api-reviewers
+labels:
+  - kind/api-change

e2e/vendor/k8s.io/apimachinery/pkg/util/validation/field/errors.go

@@ -0,0 +1,323 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package field
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// Error is an implementation of the 'error' interface, which represents a
+// field-level validation error.
+type Error struct {
+	Type     ErrorType
+	Field    string
+	BadValue interface{}
+	Detail   string
+}
+
+var _ error = &Error{}
+
+// Error implements the error interface.
+func (v *Error) Error() string {
+	return fmt.Sprintf("%s: %s", v.Field, v.ErrorBody())
+}
+
+type OmitValueType struct{}
+
+var omitValue = OmitValueType{}
+
+// ErrorBody returns the error message without the field name.  This is useful
+// for building nice-looking higher-level error reporting.
+func (v *Error) ErrorBody() string {
+	var s string
+	switch {
+	case v.Type == ErrorTypeRequired:
+		s = v.Type.String()
+	case v.Type == ErrorTypeForbidden:
+		s = v.Type.String()
+	case v.Type == ErrorTypeTooLong:
+		s = v.Type.String()
+	case v.Type == ErrorTypeInternal:
+		s = v.Type.String()
+	case v.BadValue == omitValue:
+		s = v.Type.String()
+	default:
+		value := v.BadValue
+		valueType := reflect.TypeOf(value)
+		if value == nil || valueType == nil {
+			value = "null"
+		} else if valueType.Kind() == reflect.Pointer {
+			if reflectValue := reflect.ValueOf(value); reflectValue.IsNil() {
+				value = "null"
+			} else {
+				value = reflectValue.Elem().Interface()
+			}
+		}
+		switch t := value.(type) {
+		case int64, int32, float64, float32, bool:
+			// use simple printer for simple types
+			s = fmt.Sprintf("%s: %v", v.Type, value)
+		case string:
+			s = fmt.Sprintf("%s: %q", v.Type, t)
+		case fmt.Stringer:
+			// anything that defines String() is better than raw struct
+			s = fmt.Sprintf("%s: %s", v.Type, t.String())
+		default:
+			// fallback to raw struct
+			// TODO: internal types have panic guards against json.Marshalling to prevent
+			// accidental use of internal types in external serialized form.  For now, use
+			// %#v, although it would be better to show a more expressive output in the future
+			s = fmt.Sprintf("%s: %#v", v.Type, value)
+		}
+	}
+	if len(v.Detail) != 0 {
+		s += fmt.Sprintf(": %s", v.Detail)
+	}
+	return s
+}
+
+// ErrorType is a machine readable value providing more detail about why
+// a field is invalid.  These values are expected to match 1-1 with
+// CauseType in api/types.go.
+type ErrorType string
+
+// TODO: These values are duplicated in api/types.go, but there's a circular dep.  Fix it.
+const (
+	// ErrorTypeNotFound is used to report failure to find a requested value
+	// (e.g. looking up an ID).  See NotFound().
+	ErrorTypeNotFound ErrorType = "FieldValueNotFound"
+	// ErrorTypeRequired is used to report required values that are not
+	// provided (e.g. empty strings, null values, or empty arrays).  See
+	// Required().
+	ErrorTypeRequired ErrorType = "FieldValueRequired"
+	// ErrorTypeDuplicate is used to report collisions of values that must be
+	// unique (e.g. unique IDs).  See Duplicate().
+	ErrorTypeDuplicate ErrorType = "FieldValueDuplicate"
+	// ErrorTypeInvalid is used to report malformed values (e.g. failed regex
+	// match, too long, out of bounds).  See Invalid().
+	ErrorTypeInvalid ErrorType = "FieldValueInvalid"
+	// ErrorTypeNotSupported is used to report unknown values for enumerated
+	// fields (e.g. a list of valid values).  See NotSupported().
+	ErrorTypeNotSupported ErrorType = "FieldValueNotSupported"
+	// ErrorTypeForbidden is used to report valid (as per formatting rules)
+	// values which would be accepted under some conditions, but which are not
+	// permitted by the current conditions (such as security policy).  See
+	// Forbidden().
+	ErrorTypeForbidden ErrorType = "FieldValueForbidden"
+	// ErrorTypeTooLong is used to report that the given value is too long.
+	// This is similar to ErrorTypeInvalid, but the error will not include the
+	// too-long value.  See TooLong().
+	ErrorTypeTooLong ErrorType = "FieldValueTooLong"
+	// ErrorTypeTooMany is used to report "too many". This is used to
+	// report that a given list has too many items. This is similar to FieldValueTooLong,
+	// but the error indicates quantity instead of length.
+	ErrorTypeTooMany ErrorType = "FieldValueTooMany"
+	// ErrorTypeInternal is used to report other errors that are not related
+	// to user input.  See InternalError().
+	ErrorTypeInternal ErrorType = "InternalError"
+	// ErrorTypeTypeInvalid is for the value did not match the schema type for that field
+	ErrorTypeTypeInvalid ErrorType = "FieldValueTypeInvalid"
+)
+
+// String converts a ErrorType into its corresponding canonical error message.
+func (t ErrorType) String() string {
+	switch t {
+	case ErrorTypeNotFound:
+		return "Not found"
+	case ErrorTypeRequired:
+		return "Required value"
+	case ErrorTypeDuplicate:
+		return "Duplicate value"
+	case ErrorTypeInvalid:
+		return "Invalid value"
+	case ErrorTypeNotSupported:
+		return "Unsupported value"
+	case ErrorTypeForbidden:
+		return "Forbidden"
+	case ErrorTypeTooLong:
+		return "Too long"
+	case ErrorTypeTooMany:
+		return "Too many"
+	case ErrorTypeInternal:
+		return "Internal error"
+	case ErrorTypeTypeInvalid:
+		return "Invalid value"
+	default:
+		panic(fmt.Sprintf("unrecognized validation error: %q", string(t)))
+	}
+}
+
+// TypeInvalid returns a *Error indicating "type is invalid"
+func TypeInvalid(field *Path, value interface{}, detail string) *Error {
+	return &Error{ErrorTypeTypeInvalid, field.String(), value, detail}
+}
+
+// NotFound returns a *Error indicating "value not found".  This is
+// used to report failure to find a requested value (e.g. looking up an ID).
+func NotFound(field *Path, value interface{}) *Error {
+	return &Error{ErrorTypeNotFound, field.String(), value, ""}
+}
+
+// Required returns a *Error indicating "value required".  This is used
+// to report required values that are not provided (e.g. empty strings, null
+// values, or empty arrays).
+func Required(field *Path, detail string) *Error {
+	return &Error{ErrorTypeRequired, field.String(), "", detail}
+}
+
+// Duplicate returns a *Error indicating "duplicate value".  This is
+// used to report collisions of values that must be unique (e.g. names or IDs).
+func Duplicate(field *Path, value interface{}) *Error {
+	return &Error{ErrorTypeDuplicate, field.String(), value, ""}
+}
+
+// Invalid returns a *Error indicating "invalid value".  This is used
+// to report malformed values (e.g. failed regex match, too long, out of bounds).
+func Invalid(field *Path, value interface{}, detail string) *Error {
+	return &Error{ErrorTypeInvalid, field.String(), value, detail}
+}
+
+// NotSupported returns a *Error indicating "unsupported value".
+// This is used to report unknown values for enumerated fields (e.g. a list of
+// valid values).
+func NotSupported[T ~string](field *Path, value interface{}, validValues []T) *Error {
+	detail := ""
+	if len(validValues) > 0 {
+		quotedValues := make([]string, len(validValues))
+		for i, v := range validValues {
+			quotedValues[i] = strconv.Quote(fmt.Sprint(v))
+		}
+		detail = "supported values: " + strings.Join(quotedValues, ", ")
+	}
+	return &Error{ErrorTypeNotSupported, field.String(), value, detail}
+}
+
+// Forbidden returns a *Error indicating "forbidden".  This is used to
+// report valid (as per formatting rules) values which would be accepted under
+// some conditions, but which are not permitted by current conditions (e.g.
+// security policy).
+func Forbidden(field *Path, detail string) *Error {
+	return &Error{ErrorTypeForbidden, field.String(), "", detail}
+}
+
+// TooLong returns a *Error indicating "too long".  This is used to report that
+// the given value is too long.  This is similar to Invalid, but the returned
+// error will not include the too-long value. If maxLength is negative, it will
+// be included in the message.  The value argument is not used.
+func TooLong(field *Path, value interface{}, maxLength int) *Error {
+	var msg string
+	if maxLength >= 0 {
+		msg = fmt.Sprintf("may not be more than %d bytes", maxLength)
+	} else {
+		msg = "value is too long"
+	}
+	return &Error{ErrorTypeTooLong, field.String(), "<value omitted>", msg}
+}
+
+// TooLongMaxLength returns a *Error indicating "too long".
+// Deprecated: Use TooLong instead.
+func TooLongMaxLength(field *Path, value interface{}, maxLength int) *Error {
+	return TooLong(field, "", maxLength)
+}
+
+// TooMany returns a *Error indicating "too many". This is used to
+// report that a given list has too many items. This is similar to TooLong,
+// but the returned error indicates quantity instead of length.
+func TooMany(field *Path, actualQuantity, maxQuantity int) *Error {
+	var msg string
+
+	if maxQuantity >= 0 {
+		msg = fmt.Sprintf("must have at most %d items", maxQuantity)
+	} else {
+		msg = "has too many items"
+	}
+
+	var actual interface{}
+	if actualQuantity >= 0 {
+		actual = actualQuantity
+	} else {
+		actual = omitValue
+	}
+
+	return &Error{ErrorTypeTooMany, field.String(), actual, msg}
+}
+
+// InternalError returns a *Error indicating "internal error".  This is used
+// to signal that an error was found that was not directly related to user
+// input.  The err argument must be non-nil.
+func InternalError(field *Path, err error) *Error {
+	return &Error{ErrorTypeInternal, field.String(), nil, err.Error()}
+}
+
+// ErrorList holds a set of Errors.  It is plausible that we might one day have
+// non-field errors in this same umbrella package, but for now we don't, so
+// we can keep it simple and leave ErrorList here.
+type ErrorList []*Error
+
+// NewErrorTypeMatcher returns an errors.Matcher that returns true
+// if the provided error is a Error and has the provided ErrorType.
+func NewErrorTypeMatcher(t ErrorType) utilerrors.Matcher {
+	return func(err error) bool {
+		if e, ok := err.(*Error); ok {
+			return e.Type == t
+		}
+		return false
+	}
+}
+
+// ToAggregate converts the ErrorList into an errors.Aggregate.
+func (list ErrorList) ToAggregate() utilerrors.Aggregate {
+	if len(list) == 0 {
+		return nil
+	}
+	errs := make([]error, 0, len(list))
+	errorMsgs := sets.NewString()
+	for _, err := range list {
+		msg := fmt.Sprintf("%v", err)
+		if errorMsgs.Has(msg) {
+			continue
+		}
+		errorMsgs.Insert(msg)
+		errs = append(errs, err)
+	}
+	return utilerrors.NewAggregate(errs)
+}
+
+func fromAggregate(agg utilerrors.Aggregate) ErrorList {
+	errs := agg.Errors()
+	list := make(ErrorList, len(errs))
+	for i := range errs {
+		list[i] = errs[i].(*Error)
+	}
+	return list
+}
+
+// Filter removes items from the ErrorList that match the provided fns.
+func (list ErrorList) Filter(fns ...utilerrors.Matcher) ErrorList {
+	err := utilerrors.FilterOut(list.ToAggregate(), fns...)
+	if err == nil {
+		return nil
+	}
+	// FilterOut takes an Aggregate and returns an Aggregate
+	return fromAggregate(err.(utilerrors.Aggregate))
+}

e2e/vendor/k8s.io/apimachinery/pkg/util/validation/field/path.go

@@ -0,0 +1,117 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package field
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+)
+
+type pathOptions struct {
+	path *Path
+}
+
+// PathOption modifies a pathOptions
+type PathOption func(o *pathOptions)
+
+// WithPath generates a PathOption
+func WithPath(p *Path) PathOption {
+	return func(o *pathOptions) {
+		o.path = p
+	}
+}
+
+// ToPath produces *Path from a set of PathOption
+func ToPath(opts ...PathOption) *Path {
+	c := &pathOptions{}
+	for _, opt := range opts {
+		opt(c)
+	}
+	return c.path
+}
+
+// Path represents the path from some root to a particular field.
+type Path struct {
+	name   string // the name of this field or "" if this is an index
+	index  string // if name == "", this is a subscript (index or map key) of the previous element
+	parent *Path  // nil if this is the root element
+}
+
+// NewPath creates a root Path object.
+func NewPath(name string, moreNames ...string) *Path {
+	r := &Path{name: name, parent: nil}
+	for _, anotherName := range moreNames {
+		r = &Path{name: anotherName, parent: r}
+	}
+	return r
+}
+
+// Root returns the root element of this Path.
+func (p *Path) Root() *Path {
+	for ; p.parent != nil; p = p.parent {
+		// Do nothing.
+	}
+	return p
+}
+
+// Child creates a new Path that is a child of the method receiver.
+func (p *Path) Child(name string, moreNames ...string) *Path {
+	r := NewPath(name, moreNames...)
+	r.Root().parent = p
+	return r
+}
+
+// Index indicates that the previous Path is to be subscripted by an int.
+// This sets the same underlying value as Key.
+func (p *Path) Index(index int) *Path {
+	return &Path{index: strconv.Itoa(index), parent: p}
+}
+
+// Key indicates that the previous Path is to be subscripted by a string.
+// This sets the same underlying value as Index.
+func (p *Path) Key(key string) *Path {
+	return &Path{index: key, parent: p}
+}
+
+// String produces a string representation of the Path.
+func (p *Path) String() string {
+	if p == nil {
+		return "<nil>"
+	}
+	// make a slice to iterate
+	elems := []*Path{}
+	for ; p != nil; p = p.parent {
+		elems = append(elems, p)
+	}
+
+	// iterate, but it has to be backwards
+	buf := bytes.NewBuffer(nil)
+	for i := range elems {
+		p := elems[len(elems)-1-i]
+		if p.parent != nil && len(p.name) > 0 {
+			// This is either the root or it is a subscript.
+			buf.WriteString(".")
+		}
+		if len(p.name) > 0 {
+			buf.WriteString(p.name)
+		} else {
+			fmt.Fprintf(buf, "[%s]", p.index)
+		}
+	}
+	return buf.String()
+}

e2e/vendor/k8s.io/apimachinery/pkg/util/validation/validation.go

@@ -0,0 +1,545 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package validation
+
+import (
+	"fmt"
+	"math"
+	"regexp"
+	"strings"
+	"unicode"
+
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	netutils "k8s.io/utils/net"
+)
+
+const qnameCharFmt string = "[A-Za-z0-9]"
+const qnameExtCharFmt string = "[-A-Za-z0-9_.]"
+const qualifiedNameFmt string = "(" + qnameCharFmt + qnameExtCharFmt + "*)?" + qnameCharFmt
+const qualifiedNameErrMsg string = "must consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character"
+const qualifiedNameMaxLength int = 63
+
+var qualifiedNameRegexp = regexp.MustCompile("^" + qualifiedNameFmt + "$")
+
+// IsQualifiedName tests whether the value passed is what Kubernetes calls a
+// "qualified name".  This is a format used in various places throughout the
+// system.  If the value is not valid, a list of error strings is returned.
+// Otherwise an empty list (or nil) is returned.
+func IsQualifiedName(value string) []string {
+	var errs []string
+	parts := strings.Split(value, "/")
+	var name string
+	switch len(parts) {
+	case 1:
+		name = parts[0]
+	case 2:
+		var prefix string
+		prefix, name = parts[0], parts[1]
+		if len(prefix) == 0 {
+			errs = append(errs, "prefix part "+EmptyError())
+		} else if msgs := IsDNS1123Subdomain(prefix); len(msgs) != 0 {
+			errs = append(errs, prefixEach(msgs, "prefix part ")...)
+		}
+	default:
+		return append(errs, "a qualified name "+RegexError(qualifiedNameErrMsg, qualifiedNameFmt, "MyName", "my.name", "123-abc")+
+			" with an optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')")
+	}
+
+	if len(name) == 0 {
+		errs = append(errs, "name part "+EmptyError())
+	} else if len(name) > qualifiedNameMaxLength {
+		errs = append(errs, "name part "+MaxLenError(qualifiedNameMaxLength))
+	}
+	if !qualifiedNameRegexp.MatchString(name) {
+		errs = append(errs, "name part "+RegexError(qualifiedNameErrMsg, qualifiedNameFmt, "MyName", "my.name", "123-abc"))
+	}
+	return errs
+}
+
+// IsFullyQualifiedName checks if the name is fully qualified. This is similar
+// to IsFullyQualifiedDomainName but requires a minimum of 3 segments instead of
+// 2 and does not accept a trailing . as valid.
+// TODO: This function is deprecated and preserved until all callers migrate to
+// IsFullyQualifiedDomainName; please don't add new callers.
+func IsFullyQualifiedName(fldPath *field.Path, name string) field.ErrorList {
+	var allErrors field.ErrorList
+	if len(name) == 0 {
+		return append(allErrors, field.Required(fldPath, ""))
+	}
+	if errs := IsDNS1123Subdomain(name); len(errs) > 0 {
+		return append(allErrors, field.Invalid(fldPath, name, strings.Join(errs, ",")))
+	}
+	if len(strings.Split(name, ".")) < 3 {
+		return append(allErrors, field.Invalid(fldPath, name, "should be a domain with at least three segments separated by dots"))
+	}
+	return allErrors
+}
+
+// IsFullyQualifiedDomainName checks if the domain name is fully qualified. This
+// is similar to IsFullyQualifiedName but only requires a minimum of 2 segments
+// instead of 3 and accepts a trailing . as valid.
+func IsFullyQualifiedDomainName(fldPath *field.Path, name string) field.ErrorList {
+	var allErrors field.ErrorList
+	if len(name) == 0 {
+		return append(allErrors, field.Required(fldPath, ""))
+	}
+	if strings.HasSuffix(name, ".") {
+		name = name[:len(name)-1]
+	}
+	if errs := IsDNS1123Subdomain(name); len(errs) > 0 {
+		return append(allErrors, field.Invalid(fldPath, name, strings.Join(errs, ",")))
+	}
+	if len(strings.Split(name, ".")) < 2 {
+		return append(allErrors, field.Invalid(fldPath, name, "should be a domain with at least two segments separated by dots"))
+	}
+	for _, label := range strings.Split(name, ".") {
+		if errs := IsDNS1123Label(label); len(errs) > 0 {
+			return append(allErrors, field.Invalid(fldPath, label, strings.Join(errs, ",")))
+		}
+	}
+	return allErrors
+}
+
+// Allowed characters in an HTTP Path as defined by RFC 3986. A HTTP path may
+// contain:
+// * unreserved characters (alphanumeric, '-', '.', '_', '~')
+// * percent-encoded octets
+// * sub-delims ("!", "$", "&", "'", "(", ")", "*", "+", ",", ";", "=")
+// * a colon character (":")
+const httpPathFmt string = `[A-Za-z0-9/\-._~%!$&'()*+,;=:]+`
+
+var httpPathRegexp = regexp.MustCompile("^" + httpPathFmt + "$")
+
+// IsDomainPrefixedPath checks if the given string is a domain-prefixed path
+// (e.g. acme.io/foo). All characters before the first "/" must be a valid
+// subdomain as defined by RFC 1123. All characters trailing the first "/" must
+// be valid HTTP Path characters as defined by RFC 3986.
+func IsDomainPrefixedPath(fldPath *field.Path, dpPath string) field.ErrorList {
+	var allErrs field.ErrorList
+	if len(dpPath) == 0 {
+		return append(allErrs, field.Required(fldPath, ""))
+	}
+
+	segments := strings.SplitN(dpPath, "/", 2)
+	if len(segments) != 2 || len(segments[0]) == 0 || len(segments[1]) == 0 {
+		return append(allErrs, field.Invalid(fldPath, dpPath, "must be a domain-prefixed path (such as \"acme.io/foo\")"))
+	}
+
+	host := segments[0]
+	for _, err := range IsDNS1123Subdomain(host) {
+		allErrs = append(allErrs, field.Invalid(fldPath, host, err))
+	}
+
+	path := segments[1]
+	if !httpPathRegexp.MatchString(path) {
+		return append(allErrs, field.Invalid(fldPath, path, RegexError("Invalid path", httpPathFmt)))
+	}
+
+	return allErrs
+}
+
+const labelValueFmt string = "(" + qualifiedNameFmt + ")?"
+const labelValueErrMsg string = "a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character"
+
+// LabelValueMaxLength is a label's max length
+const LabelValueMaxLength int = 63
+
+var labelValueRegexp = regexp.MustCompile("^" + labelValueFmt + "$")
+
+// IsValidLabelValue tests whether the value passed is a valid label value.  If
+// the value is not valid, a list of error strings is returned.  Otherwise an
+// empty list (or nil) is returned.
+func IsValidLabelValue(value string) []string {
+	var errs []string
+	if len(value) > LabelValueMaxLength {
+		errs = append(errs, MaxLenError(LabelValueMaxLength))
+	}
+	if !labelValueRegexp.MatchString(value) {
+		errs = append(errs, RegexError(labelValueErrMsg, labelValueFmt, "MyValue", "my_value", "12345"))
+	}
+	return errs
+}
+
+const dns1123LabelFmt string = "[a-z0-9]([-a-z0-9]*[a-z0-9])?"
+const dns1123LabelFmtWithUnderscore string = "_?[a-z0-9]([-_a-z0-9]*[a-z0-9])?"
+
+const dns1123LabelErrMsg string = "a lowercase RFC 1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character"
+
+// DNS1123LabelMaxLength is a label's max length in DNS (RFC 1123)
+const DNS1123LabelMaxLength int = 63
+
+var dns1123LabelRegexp = regexp.MustCompile("^" + dns1123LabelFmt + "$")
+
+// IsDNS1123Label tests for a string that conforms to the definition of a label in
+// DNS (RFC 1123).
+func IsDNS1123Label(value string) []string {
+	var errs []string
+	if len(value) > DNS1123LabelMaxLength {
+		errs = append(errs, MaxLenError(DNS1123LabelMaxLength))
+	}
+	if !dns1123LabelRegexp.MatchString(value) {
+		if dns1123SubdomainRegexp.MatchString(value) {
+			// It was a valid subdomain and not a valid label.  Since we
+			// already checked length, it must be dots.
+			errs = append(errs, "must not contain dots")
+		} else {
+			errs = append(errs, RegexError(dns1123LabelErrMsg, dns1123LabelFmt, "my-name", "123-abc"))
+		}
+	}
+	return errs
+}
+
+const dns1123SubdomainFmt string = dns1123LabelFmt + "(\\." + dns1123LabelFmt + ")*"
+const dns1123SubdomainErrorMsg string = "a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character"
+
+const dns1123SubdomainFmtWithUnderscore string = dns1123LabelFmtWithUnderscore + "(\\." + dns1123LabelFmtWithUnderscore + ")*"
+const dns1123SubdomainErrorMsgFG string = "a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '_', '-' or '.', and must start and end with an alphanumeric character"
+
+// DNS1123SubdomainMaxLength is a subdomain's max length in DNS (RFC 1123)
+const DNS1123SubdomainMaxLength int = 253
+
+var dns1123SubdomainRegexp = regexp.MustCompile("^" + dns1123SubdomainFmt + "$")
+var dns1123SubdomainRegexpWithUnderscore = regexp.MustCompile("^" + dns1123SubdomainFmtWithUnderscore + "$")
+
+// IsDNS1123Subdomain tests for a string that conforms to the definition of a
+// subdomain in DNS (RFC 1123).
+func IsDNS1123Subdomain(value string) []string {
+	var errs []string
+	if len(value) > DNS1123SubdomainMaxLength {
+		errs = append(errs, MaxLenError(DNS1123SubdomainMaxLength))
+	}
+	if !dns1123SubdomainRegexp.MatchString(value) {
+		errs = append(errs, RegexError(dns1123SubdomainErrorMsg, dns1123SubdomainFmt, "example.com"))
+	}
+	return errs
+}
+
+// IsDNS1123SubdomainWithUnderscore tests for a string that conforms to the definition of a
+// subdomain in DNS (RFC 1123), but allows the use of an underscore in the string
+func IsDNS1123SubdomainWithUnderscore(value string) []string {
+	var errs []string
+	if len(value) > DNS1123SubdomainMaxLength {
+		errs = append(errs, MaxLenError(DNS1123SubdomainMaxLength))
+	}
+	if !dns1123SubdomainRegexpWithUnderscore.MatchString(value) {
+		errs = append(errs, RegexError(dns1123SubdomainErrorMsgFG, dns1123SubdomainFmt, "example.com"))
+	}
+	return errs
+}
+
+const dns1035LabelFmt string = "[a-z]([-a-z0-9]*[a-z0-9])?"
+const dns1035LabelErrMsg string = "a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character"
+
+// DNS1035LabelMaxLength is a label's max length in DNS (RFC 1035)
+const DNS1035LabelMaxLength int = 63
+
+var dns1035LabelRegexp = regexp.MustCompile("^" + dns1035LabelFmt + "$")
+
+// IsDNS1035Label tests for a string that conforms to the definition of a label in
+// DNS (RFC 1035).
+func IsDNS1035Label(value string) []string {
+	var errs []string
+	if len(value) > DNS1035LabelMaxLength {
+		errs = append(errs, MaxLenError(DNS1035LabelMaxLength))
+	}
+	if !dns1035LabelRegexp.MatchString(value) {
+		errs = append(errs, RegexError(dns1035LabelErrMsg, dns1035LabelFmt, "my-name", "abc-123"))
+	}
+	return errs
+}
+
+// wildcard definition - RFC 1034 section 4.3.3.
+// examples:
+// - valid: *.bar.com, *.foo.bar.com
+// - invalid: *.*.bar.com, *.foo.*.com, *bar.com, f*.bar.com, *
+const wildcardDNS1123SubdomainFmt = "\\*\\." + dns1123SubdomainFmt
+const wildcardDNS1123SubdomainErrMsg = "a wildcard DNS-1123 subdomain must start with '*.', followed by a valid DNS subdomain, which must consist of lower case alphanumeric characters, '-' or '.' and end with an alphanumeric character"
+
+// IsWildcardDNS1123Subdomain tests for a string that conforms to the definition of a
+// wildcard subdomain in DNS (RFC 1034 section 4.3.3).
+func IsWildcardDNS1123Subdomain(value string) []string {
+	wildcardDNS1123SubdomainRegexp := regexp.MustCompile("^" + wildcardDNS1123SubdomainFmt + "$")
+
+	var errs []string
+	if len(value) > DNS1123SubdomainMaxLength {
+		errs = append(errs, MaxLenError(DNS1123SubdomainMaxLength))
+	}
+	if !wildcardDNS1123SubdomainRegexp.MatchString(value) {
+		errs = append(errs, RegexError(wildcardDNS1123SubdomainErrMsg, wildcardDNS1123SubdomainFmt, "*.example.com"))
+	}
+	return errs
+}
+
+const cIdentifierFmt string = "[A-Za-z_][A-Za-z0-9_]*"
+const identifierErrMsg string = "a valid C identifier must start with alphabetic character or '_', followed by a string of alphanumeric characters or '_'"
+
+var cIdentifierRegexp = regexp.MustCompile("^" + cIdentifierFmt + "$")
+
+// IsCIdentifier tests for a string that conforms the definition of an identifier
+// in C. This checks the format, but not the length.
+func IsCIdentifier(value string) []string {
+	if !cIdentifierRegexp.MatchString(value) {
+		return []string{RegexError(identifierErrMsg, cIdentifierFmt, "my_name", "MY_NAME", "MyName")}
+	}
+	return nil
+}
+
+// IsValidPortNum tests that the argument is a valid, non-zero port number.
+func IsValidPortNum(port int) []string {
+	if 1 <= port && port <= 65535 {
+		return nil
+	}
+	return []string{InclusiveRangeError(1, 65535)}
+}
+
+// IsInRange tests that the argument is in an inclusive range.
+func IsInRange(value int, min int, max int) []string {
+	if value >= min && value <= max {
+		return nil
+	}
+	return []string{InclusiveRangeError(min, max)}
+}
+
+// Now in libcontainer UID/GID limits is 0 ~ 1<<31 - 1
+// TODO: once we have a type for UID/GID we should make these that type.
+const (
+	minUserID  = 0
+	maxUserID  = math.MaxInt32
+	minGroupID = 0
+	maxGroupID = math.MaxInt32
+)
+
+// IsValidGroupID tests that the argument is a valid Unix GID.
+func IsValidGroupID(gid int64) []string {
+	if minGroupID <= gid && gid <= maxGroupID {
+		return nil
+	}
+	return []string{InclusiveRangeError(minGroupID, maxGroupID)}
+}
+
+// IsValidUserID tests that the argument is a valid Unix UID.
+func IsValidUserID(uid int64) []string {
+	if minUserID <= uid && uid <= maxUserID {
+		return nil
+	}
+	return []string{InclusiveRangeError(minUserID, maxUserID)}
+}
+
+var portNameCharsetRegex = regexp.MustCompile("^[-a-z0-9]+$")
+var portNameOneLetterRegexp = regexp.MustCompile("[a-z]")
+
+// IsValidPortName check that the argument is valid syntax. It must be
+// non-empty and no more than 15 characters long. It may contain only [-a-z0-9]
+// and must contain at least one letter [a-z]. It must not start or end with a
+// hyphen, nor contain adjacent hyphens.
+//
+// Note: We only allow lower-case characters, even though RFC 6335 is case
+// insensitive.
+func IsValidPortName(port string) []string {
+	var errs []string
+	if len(port) > 15 {
+		errs = append(errs, MaxLenError(15))
+	}
+	if !portNameCharsetRegex.MatchString(port) {
+		errs = append(errs, "must contain only alpha-numeric characters (a-z, 0-9), and hyphens (-)")
+	}
+	if !portNameOneLetterRegexp.MatchString(port) {
+		errs = append(errs, "must contain at least one letter (a-z)")
+	}
+	if strings.Contains(port, "--") {
+		errs = append(errs, "must not contain consecutive hyphens")
+	}
+	if len(port) > 0 && (port[0] == '-' || port[len(port)-1] == '-') {
+		errs = append(errs, "must not begin or end with a hyphen")
+	}
+	return errs
+}
+
+// IsValidIP tests that the argument is a valid IP address.
+func IsValidIP(fldPath *field.Path, value string) field.ErrorList {
+	var allErrors field.ErrorList
+	if netutils.ParseIPSloppy(value) == nil {
+		allErrors = append(allErrors, field.Invalid(fldPath, value, "must be a valid IP address, (e.g. 10.9.8.7 or 2001:db8::ffff)"))
+	}
+	return allErrors
+}
+
+// IsValidIPv4Address tests that the argument is a valid IPv4 address.
+func IsValidIPv4Address(fldPath *field.Path, value string) field.ErrorList {
+	var allErrors field.ErrorList
+	ip := netutils.ParseIPSloppy(value)
+	if ip == nil || ip.To4() == nil {
+		allErrors = append(allErrors, field.Invalid(fldPath, value, "must be a valid IPv4 address"))
+	}
+	return allErrors
+}
+
+// IsValidIPv6Address tests that the argument is a valid IPv6 address.
+func IsValidIPv6Address(fldPath *field.Path, value string) field.ErrorList {
+	var allErrors field.ErrorList
+	ip := netutils.ParseIPSloppy(value)
+	if ip == nil || ip.To4() != nil {
+		allErrors = append(allErrors, field.Invalid(fldPath, value, "must be a valid IPv6 address"))
+	}
+	return allErrors
+}
+
+// IsValidCIDR tests that the argument is a valid CIDR value.
+func IsValidCIDR(fldPath *field.Path, value string) field.ErrorList {
+	var allErrors field.ErrorList
+	_, _, err := netutils.ParseCIDRSloppy(value)
+	if err != nil {
+		allErrors = append(allErrors, field.Invalid(fldPath, value, "must be a valid CIDR value, (e.g. 10.9.8.0/24 or 2001:db8::/64)"))
+	}
+	return allErrors
+}
+
+const percentFmt string = "[0-9]+%"
+const percentErrMsg string = "a valid percent string must be a numeric string followed by an ending '%'"
+
+var percentRegexp = regexp.MustCompile("^" + percentFmt + "$")
+
+// IsValidPercent checks that string is in the form of a percentage
+func IsValidPercent(percent string) []string {
+	if !percentRegexp.MatchString(percent) {
+		return []string{RegexError(percentErrMsg, percentFmt, "1%", "93%")}
+	}
+	return nil
+}
+
+const httpHeaderNameFmt string = "[-A-Za-z0-9]+"
+const httpHeaderNameErrMsg string = "a valid HTTP header must consist of alphanumeric characters or '-'"
+
+var httpHeaderNameRegexp = regexp.MustCompile("^" + httpHeaderNameFmt + "$")
+
+// IsHTTPHeaderName checks that a string conforms to the Go HTTP library's
+// definition of a valid header field name (a stricter subset than RFC7230).
+func IsHTTPHeaderName(value string) []string {
+	if !httpHeaderNameRegexp.MatchString(value) {
+		return []string{RegexError(httpHeaderNameErrMsg, httpHeaderNameFmt, "X-Header-Name")}
+	}
+	return nil
+}
+
+const envVarNameFmt = "[-._a-zA-Z][-._a-zA-Z0-9]*"
+const envVarNameFmtErrMsg string = "a valid environment variable name must consist of alphabetic characters, digits, '_', '-', or '.', and must not start with a digit"
+
+// TODO(hirazawaui): Rename this when the RelaxedEnvironmentVariableValidation gate is removed.
+const relaxedEnvVarNameFmtErrMsg string = "a valid environment variable name must consist only of printable ASCII characters other than '='"
+
+var envVarNameRegexp = regexp.MustCompile("^" + envVarNameFmt + "$")
+
+// IsEnvVarName tests if a string is a valid environment variable name.
+func IsEnvVarName(value string) []string {
+	var errs []string
+	if !envVarNameRegexp.MatchString(value) {
+		errs = append(errs, RegexError(envVarNameFmtErrMsg, envVarNameFmt, "my.env-name", "MY_ENV.NAME", "MyEnvName1"))
+	}
+
+	errs = append(errs, hasChDirPrefix(value)...)
+	return errs
+}
+
+// IsRelaxedEnvVarName tests if a string is a valid environment variable name.
+func IsRelaxedEnvVarName(value string) []string {
+	var errs []string
+
+	if len(value) == 0 {
+		errs = append(errs, "environment variable name "+EmptyError())
+	}
+
+	for _, r := range value {
+		if r > unicode.MaxASCII || !unicode.IsPrint(r) || r == '=' {
+			errs = append(errs, relaxedEnvVarNameFmtErrMsg)
+			break
+		}
+	}
+
+	return errs
+}
+
+const configMapKeyFmt = `[-._a-zA-Z0-9]+`
+const configMapKeyErrMsg string = "a valid config key must consist of alphanumeric characters, '-', '_' or '.'"
+
+var configMapKeyRegexp = regexp.MustCompile("^" + configMapKeyFmt + "$")
+
+// IsConfigMapKey tests for a string that is a valid key for a ConfigMap or Secret
+func IsConfigMapKey(value string) []string {
+	var errs []string
+	if len(value) > DNS1123SubdomainMaxLength {
+		errs = append(errs, MaxLenError(DNS1123SubdomainMaxLength))
+	}
+	if !configMapKeyRegexp.MatchString(value) {
+		errs = append(errs, RegexError(configMapKeyErrMsg, configMapKeyFmt, "key.name", "KEY_NAME", "key-name"))
+	}
+	errs = append(errs, hasChDirPrefix(value)...)
+	return errs
+}
+
+// MaxLenError returns a string explanation of a "string too long" validation
+// failure.
+func MaxLenError(length int) string {
+	return fmt.Sprintf("must be no more than %d characters", length)
+}
+
+// RegexError returns a string explanation of a regex validation failure.
+func RegexError(msg string, fmt string, examples ...string) string {
+	if len(examples) == 0 {
+		return msg + " (regex used for validation is '" + fmt + "')"
+	}
+	msg += " (e.g. "
+	for i := range examples {
+		if i > 0 {
+			msg += " or "
+		}
+		msg += "'" + examples[i] + "', "
+	}
+	msg += "regex used for validation is '" + fmt + "')"
+	return msg
+}
+
+// EmptyError returns a string explanation of a "must not be empty" validation
+// failure.
+func EmptyError() string {
+	return "must be non-empty"
+}
+
+func prefixEach(msgs []string, prefix string) []string {
+	for i := range msgs {
+		msgs[i] = prefix + msgs[i]
+	}
+	return msgs
+}
+
+// InclusiveRangeError returns a string explanation of a numeric "must be
+// between" validation failure.
+func InclusiveRangeError(lo, hi int) string {
+	return fmt.Sprintf(`must be between %d and %d, inclusive`, lo, hi)
+}
+
+func hasChDirPrefix(value string) []string {
+	var errs []string
+	switch {
+	case value == ".":
+		errs = append(errs, `must not be '.'`)
+	case value == "..":
+		errs = append(errs, `must not be '..'`)
+	case strings.HasPrefix(value, ".."):
+		errs = append(errs, `must not start with '..'`)
+	}
+	return errs
+}