traefik/vendor/k8s.io/apimachinery/pkg/api/meta/restmapper.go
2018-02-14 09:56:04 +01:00

548 lines
17 KiB
Go

/*
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.
*/
// TODO: move everything in this file to pkg/api/rest
package meta
import (
"fmt"
"sort"
"strings"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
)
// Implements RESTScope interface
type restScope struct {
name RESTScopeName
paramName string
argumentName string
paramDescription string
}
func (r *restScope) Name() RESTScopeName {
return r.name
}
func (r *restScope) ParamName() string {
return r.paramName
}
func (r *restScope) ArgumentName() string {
return r.argumentName
}
func (r *restScope) ParamDescription() string {
return r.paramDescription
}
var RESTScopeNamespace = &restScope{
name: RESTScopeNameNamespace,
paramName: "namespaces",
argumentName: "namespace",
paramDescription: "object name and auth scope, such as for teams and projects",
}
var RESTScopeRoot = &restScope{
name: RESTScopeNameRoot,
}
// DefaultRESTMapper exposes mappings between the types defined in a
// runtime.Scheme. It assumes that all types defined the provided scheme
// can be mapped with the provided MetadataAccessor and Codec interfaces.
//
// The resource name of a Kind is defined as the lowercase,
// English-plural version of the Kind string.
// When converting from resource to Kind, the singular version of the
// resource name is also accepted for convenience.
//
// TODO: Only accept plural for some operations for increased control?
// (`get pod bar` vs `get pods bar`)
type DefaultRESTMapper struct {
defaultGroupVersions []schema.GroupVersion
resourceToKind map[schema.GroupVersionResource]schema.GroupVersionKind
kindToPluralResource map[schema.GroupVersionKind]schema.GroupVersionResource
kindToScope map[schema.GroupVersionKind]RESTScope
singularToPlural map[schema.GroupVersionResource]schema.GroupVersionResource
pluralToSingular map[schema.GroupVersionResource]schema.GroupVersionResource
interfacesFunc VersionInterfacesFunc
}
func (m *DefaultRESTMapper) String() string {
return fmt.Sprintf("DefaultRESTMapper{kindToPluralResource=%v}", m.kindToPluralResource)
}
var _ RESTMapper = &DefaultRESTMapper{}
// VersionInterfacesFunc returns the appropriate typer, and metadata accessor for a
// given api version, or an error if no such api version exists.
type VersionInterfacesFunc func(version schema.GroupVersion) (*VersionInterfaces, error)
// NewDefaultRESTMapper initializes a mapping between Kind and APIVersion
// to a resource name and back based on the objects in a runtime.Scheme
// and the Kubernetes API conventions. Takes a group name, a priority list of the versions
// to search when an object has no default version (set empty to return an error),
// and a function that retrieves the correct metadata for a given version.
func NewDefaultRESTMapper(defaultGroupVersions []schema.GroupVersion, f VersionInterfacesFunc) *DefaultRESTMapper {
resourceToKind := make(map[schema.GroupVersionResource]schema.GroupVersionKind)
kindToPluralResource := make(map[schema.GroupVersionKind]schema.GroupVersionResource)
kindToScope := make(map[schema.GroupVersionKind]RESTScope)
singularToPlural := make(map[schema.GroupVersionResource]schema.GroupVersionResource)
pluralToSingular := make(map[schema.GroupVersionResource]schema.GroupVersionResource)
// TODO: verify name mappings work correctly when versions differ
return &DefaultRESTMapper{
resourceToKind: resourceToKind,
kindToPluralResource: kindToPluralResource,
kindToScope: kindToScope,
defaultGroupVersions: defaultGroupVersions,
singularToPlural: singularToPlural,
pluralToSingular: pluralToSingular,
interfacesFunc: f,
}
}
func (m *DefaultRESTMapper) Add(kind schema.GroupVersionKind, scope RESTScope) {
plural, singular := UnsafeGuessKindToResource(kind)
m.AddSpecific(kind, plural, singular, scope)
}
func (m *DefaultRESTMapper) AddSpecific(kind schema.GroupVersionKind, plural, singular schema.GroupVersionResource, scope RESTScope) {
m.singularToPlural[singular] = plural
m.pluralToSingular[plural] = singular
m.resourceToKind[singular] = kind
m.resourceToKind[plural] = kind
m.kindToPluralResource[kind] = plural
m.kindToScope[kind] = scope
}
// unpluralizedSuffixes is a list of resource suffixes that are the same plural and singular
// This is only is only necessary because some bits of code are lazy and don't actually use the RESTMapper like they should.
// TODO eliminate this so that different callers can correctly map to resources. This probably means updating all
// callers to use the RESTMapper they mean.
var unpluralizedSuffixes = []string{
"endpoints",
}
// UnsafeGuessKindToResource converts Kind to a resource name.
// Broken. This method only "sort of" works when used outside of this package. It assumes that Kinds and Resources match
// and they aren't guaranteed to do so.
func UnsafeGuessKindToResource(kind schema.GroupVersionKind) ( /*plural*/ schema.GroupVersionResource /*singular*/, schema.GroupVersionResource) {
kindName := kind.Kind
if len(kindName) == 0 {
return schema.GroupVersionResource{}, schema.GroupVersionResource{}
}
singularName := strings.ToLower(kindName)
singular := kind.GroupVersion().WithResource(singularName)
for _, skip := range unpluralizedSuffixes {
if strings.HasSuffix(singularName, skip) {
return singular, singular
}
}
switch string(singularName[len(singularName)-1]) {
case "s":
return kind.GroupVersion().WithResource(singularName + "es"), singular
case "y":
return kind.GroupVersion().WithResource(strings.TrimSuffix(singularName, "y") + "ies"), singular
}
return kind.GroupVersion().WithResource(singularName + "s"), singular
}
// ResourceSingularizer implements RESTMapper
// It converts a resource name from plural to singular (e.g., from pods to pod)
func (m *DefaultRESTMapper) ResourceSingularizer(resourceType string) (string, error) {
partialResource := schema.GroupVersionResource{Resource: resourceType}
resources, err := m.ResourcesFor(partialResource)
if err != nil {
return resourceType, err
}
singular := schema.GroupVersionResource{}
for _, curr := range resources {
currSingular, ok := m.pluralToSingular[curr]
if !ok {
continue
}
if singular.Empty() {
singular = currSingular
continue
}
if currSingular.Resource != singular.Resource {
return resourceType, fmt.Errorf("multiple possible singular resources (%v) found for %v", resources, resourceType)
}
}
if singular.Empty() {
return resourceType, fmt.Errorf("no singular of resource %v has been defined", resourceType)
}
return singular.Resource, nil
}
// coerceResourceForMatching makes the resource lower case and converts internal versions to unspecified (legacy behavior)
func coerceResourceForMatching(resource schema.GroupVersionResource) schema.GroupVersionResource {
resource.Resource = strings.ToLower(resource.Resource)
if resource.Version == runtime.APIVersionInternal {
resource.Version = ""
}
return resource
}
func (m *DefaultRESTMapper) ResourcesFor(input schema.GroupVersionResource) ([]schema.GroupVersionResource, error) {
resource := coerceResourceForMatching(input)
hasResource := len(resource.Resource) > 0
hasGroup := len(resource.Group) > 0
hasVersion := len(resource.Version) > 0
if !hasResource {
return nil, fmt.Errorf("a resource must be present, got: %v", resource)
}
ret := []schema.GroupVersionResource{}
switch {
case hasGroup && hasVersion:
// fully qualified. Find the exact match
for plural, singular := range m.pluralToSingular {
if singular == resource {
ret = append(ret, plural)
break
}
if plural == resource {
ret = append(ret, plural)
break
}
}
case hasGroup:
// given a group, prefer an exact match. If you don't find one, resort to a prefix match on group
foundExactMatch := false
requestedGroupResource := resource.GroupResource()
for plural, singular := range m.pluralToSingular {
if singular.GroupResource() == requestedGroupResource {
foundExactMatch = true
ret = append(ret, plural)
}
if plural.GroupResource() == requestedGroupResource {
foundExactMatch = true
ret = append(ret, plural)
}
}
// if you didn't find an exact match, match on group prefixing. This allows storageclass.storage to match
// storageclass.storage.k8s.io
if !foundExactMatch {
for plural, singular := range m.pluralToSingular {
if !strings.HasPrefix(plural.Group, requestedGroupResource.Group) {
continue
}
if singular.Resource == requestedGroupResource.Resource {
ret = append(ret, plural)
}
if plural.Resource == requestedGroupResource.Resource {
ret = append(ret, plural)
}
}
}
case hasVersion:
for plural, singular := range m.pluralToSingular {
if singular.Version == resource.Version && singular.Resource == resource.Resource {
ret = append(ret, plural)
}
if plural.Version == resource.Version && plural.Resource == resource.Resource {
ret = append(ret, plural)
}
}
default:
for plural, singular := range m.pluralToSingular {
if singular.Resource == resource.Resource {
ret = append(ret, plural)
}
if plural.Resource == resource.Resource {
ret = append(ret, plural)
}
}
}
if len(ret) == 0 {
return nil, &NoResourceMatchError{PartialResource: resource}
}
sort.Sort(resourceByPreferredGroupVersion{ret, m.defaultGroupVersions})
return ret, nil
}
func (m *DefaultRESTMapper) ResourceFor(resource schema.GroupVersionResource) (schema.GroupVersionResource, error) {
resources, err := m.ResourcesFor(resource)
if err != nil {
return schema.GroupVersionResource{}, err
}
if len(resources) == 1 {
return resources[0], nil
}
return schema.GroupVersionResource{}, &AmbiguousResourceError{PartialResource: resource, MatchingResources: resources}
}
func (m *DefaultRESTMapper) KindsFor(input schema.GroupVersionResource) ([]schema.GroupVersionKind, error) {
resource := coerceResourceForMatching(input)
hasResource := len(resource.Resource) > 0
hasGroup := len(resource.Group) > 0
hasVersion := len(resource.Version) > 0
if !hasResource {
return nil, fmt.Errorf("a resource must be present, got: %v", resource)
}
ret := []schema.GroupVersionKind{}
switch {
// fully qualified. Find the exact match
case hasGroup && hasVersion:
kind, exists := m.resourceToKind[resource]
if exists {
ret = append(ret, kind)
}
case hasGroup:
foundExactMatch := false
requestedGroupResource := resource.GroupResource()
for currResource, currKind := range m.resourceToKind {
if currResource.GroupResource() == requestedGroupResource {
foundExactMatch = true
ret = append(ret, currKind)
}
}
// if you didn't find an exact match, match on group prefixing. This allows storageclass.storage to match
// storageclass.storage.k8s.io
if !foundExactMatch {
for currResource, currKind := range m.resourceToKind {
if !strings.HasPrefix(currResource.Group, requestedGroupResource.Group) {
continue
}
if currResource.Resource == requestedGroupResource.Resource {
ret = append(ret, currKind)
}
}
}
case hasVersion:
for currResource, currKind := range m.resourceToKind {
if currResource.Version == resource.Version && currResource.Resource == resource.Resource {
ret = append(ret, currKind)
}
}
default:
for currResource, currKind := range m.resourceToKind {
if currResource.Resource == resource.Resource {
ret = append(ret, currKind)
}
}
}
if len(ret) == 0 {
return nil, &NoResourceMatchError{PartialResource: input}
}
sort.Sort(kindByPreferredGroupVersion{ret, m.defaultGroupVersions})
return ret, nil
}
func (m *DefaultRESTMapper) KindFor(resource schema.GroupVersionResource) (schema.GroupVersionKind, error) {
kinds, err := m.KindsFor(resource)
if err != nil {
return schema.GroupVersionKind{}, err
}
if len(kinds) == 1 {
return kinds[0], nil
}
return schema.GroupVersionKind{}, &AmbiguousResourceError{PartialResource: resource, MatchingKinds: kinds}
}
type kindByPreferredGroupVersion struct {
list []schema.GroupVersionKind
sortOrder []schema.GroupVersion
}
func (o kindByPreferredGroupVersion) Len() int { return len(o.list) }
func (o kindByPreferredGroupVersion) Swap(i, j int) { o.list[i], o.list[j] = o.list[j], o.list[i] }
func (o kindByPreferredGroupVersion) Less(i, j int) bool {
lhs := o.list[i]
rhs := o.list[j]
if lhs == rhs {
return false
}
if lhs.GroupVersion() == rhs.GroupVersion() {
return lhs.Kind < rhs.Kind
}
// otherwise, the difference is in the GroupVersion, so we need to sort with respect to the preferred order
lhsIndex := -1
rhsIndex := -1
for i := range o.sortOrder {
if o.sortOrder[i] == lhs.GroupVersion() {
lhsIndex = i
}
if o.sortOrder[i] == rhs.GroupVersion() {
rhsIndex = i
}
}
if rhsIndex == -1 {
return true
}
return lhsIndex < rhsIndex
}
type resourceByPreferredGroupVersion struct {
list []schema.GroupVersionResource
sortOrder []schema.GroupVersion
}
func (o resourceByPreferredGroupVersion) Len() int { return len(o.list) }
func (o resourceByPreferredGroupVersion) Swap(i, j int) { o.list[i], o.list[j] = o.list[j], o.list[i] }
func (o resourceByPreferredGroupVersion) Less(i, j int) bool {
lhs := o.list[i]
rhs := o.list[j]
if lhs == rhs {
return false
}
if lhs.GroupVersion() == rhs.GroupVersion() {
return lhs.Resource < rhs.Resource
}
// otherwise, the difference is in the GroupVersion, so we need to sort with respect to the preferred order
lhsIndex := -1
rhsIndex := -1
for i := range o.sortOrder {
if o.sortOrder[i] == lhs.GroupVersion() {
lhsIndex = i
}
if o.sortOrder[i] == rhs.GroupVersion() {
rhsIndex = i
}
}
if rhsIndex == -1 {
return true
}
return lhsIndex < rhsIndex
}
// RESTMapping returns a struct representing the resource path and conversion interfaces a
// RESTClient should use to operate on the provided group/kind in order of versions. If a version search
// order is not provided, the search order provided to DefaultRESTMapper will be used to resolve which
// version should be used to access the named group/kind.
func (m *DefaultRESTMapper) RESTMapping(gk schema.GroupKind, versions ...string) (*RESTMapping, error) {
mappings, err := m.RESTMappings(gk, versions...)
if err != nil {
return nil, err
}
if len(mappings) == 0 {
return nil, &NoKindMatchError{PartialKind: gk.WithVersion("")}
}
// since we rely on RESTMappings method
// take the first match and return to the caller
// as this was the existing behavior.
return mappings[0], nil
}
// RESTMappings returns the RESTMappings for the provided group kind. If a version search order
// is not provided, the search order provided to DefaultRESTMapper will be used.
func (m *DefaultRESTMapper) RESTMappings(gk schema.GroupKind, versions ...string) ([]*RESTMapping, error) {
mappings := make([]*RESTMapping, 0)
potentialGVK := make([]schema.GroupVersionKind, 0)
hadVersion := false
// Pick an appropriate version
for _, version := range versions {
if len(version) == 0 || version == runtime.APIVersionInternal {
continue
}
currGVK := gk.WithVersion(version)
hadVersion = true
if _, ok := m.kindToPluralResource[currGVK]; ok {
potentialGVK = append(potentialGVK, currGVK)
break
}
}
// Use the default preferred versions
if !hadVersion && len(potentialGVK) == 0 {
for _, gv := range m.defaultGroupVersions {
if gv.Group != gk.Group {
continue
}
potentialGVK = append(potentialGVK, gk.WithVersion(gv.Version))
}
}
if len(potentialGVK) == 0 {
return nil, &NoKindMatchError{PartialKind: gk.WithVersion("")}
}
for _, gvk := range potentialGVK {
//Ensure we have a REST mapping
res, ok := m.kindToPluralResource[gvk]
if !ok {
continue
}
// Ensure we have a REST scope
scope, ok := m.kindToScope[gvk]
if !ok {
return nil, fmt.Errorf("the provided version %q and kind %q cannot be mapped to a supported scope", gvk.GroupVersion(), gvk.Kind)
}
interfaces, err := m.interfacesFunc(gvk.GroupVersion())
if err != nil {
return nil, fmt.Errorf("the provided version %q has no relevant versions: %v", gvk.GroupVersion().String(), err)
}
mappings = append(mappings, &RESTMapping{
Resource: res.Resource,
GroupVersionKind: gvk,
Scope: scope,
ObjectConvertor: interfaces.ObjectConvertor,
MetadataAccessor: interfaces.MetadataAccessor,
})
}
if len(mappings) == 0 {
return nil, &NoResourceMatchError{PartialResource: schema.GroupVersionResource{Group: gk.Group, Resource: gk.Kind}}
}
return mappings, nil
}