mirror of
https://github.com/prometheus/prometheus.git
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346 lines
12 KiB
Go
346 lines
12 KiB
Go
/*
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Copyright 2015 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package discovery
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import (
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"encoding/json"
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"fmt"
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"net/url"
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"sort"
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"strings"
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"github.com/emicklei/go-restful/swagger"
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"k8s.io/client-go/1.5/pkg/api"
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"k8s.io/client-go/1.5/pkg/api/errors"
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"k8s.io/client-go/1.5/pkg/api/unversioned"
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"k8s.io/client-go/1.5/pkg/api/v1"
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"k8s.io/client-go/1.5/pkg/runtime"
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"k8s.io/client-go/1.5/pkg/runtime/serializer"
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"k8s.io/client-go/1.5/pkg/version"
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"k8s.io/client-go/1.5/rest"
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)
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// DiscoveryInterface holds the methods that discover server-supported API groups,
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// versions and resources.
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type DiscoveryInterface interface {
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ServerGroupsInterface
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ServerResourcesInterface
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ServerVersionInterface
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SwaggerSchemaInterface
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}
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// ServerGroupsInterface has methods for obtaining supported groups on the API server
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type ServerGroupsInterface interface {
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// ServerGroups returns the supported groups, with information like supported versions and the
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// preferred version.
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ServerGroups() (*unversioned.APIGroupList, error)
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}
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// ServerResourcesInterface has methods for obtaining supported resources on the API server
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type ServerResourcesInterface interface {
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// ServerResourcesForGroupVersion returns the supported resources for a group and version.
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ServerResourcesForGroupVersion(groupVersion string) (*unversioned.APIResourceList, error)
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// ServerResources returns the supported resources for all groups and versions.
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ServerResources() (map[string]*unversioned.APIResourceList, error)
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// ServerPreferredResources returns the supported resources with the version preferred by the
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// server.
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ServerPreferredResources() ([]unversioned.GroupVersionResource, error)
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// ServerPreferredNamespacedResources returns the supported namespaced resources with the
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// version preferred by the server.
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ServerPreferredNamespacedResources() ([]unversioned.GroupVersionResource, error)
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}
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// ServerVersionInterface has a method for retrieving the server's version.
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type ServerVersionInterface interface {
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// ServerVersion retrieves and parses the server's version (git version).
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ServerVersion() (*version.Info, error)
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}
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// SwaggerSchemaInterface has a method to retrieve the swagger schema.
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type SwaggerSchemaInterface interface {
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// SwaggerSchema retrieves and parses the swagger API schema the server supports.
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SwaggerSchema(version unversioned.GroupVersion) (*swagger.ApiDeclaration, error)
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}
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// DiscoveryClient implements the functions that discover server-supported API groups,
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// versions and resources.
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type DiscoveryClient struct {
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*rest.RESTClient
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LegacyPrefix string
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}
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// Convert unversioned.APIVersions to unversioned.APIGroup. APIVersions is used by legacy v1, so
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// group would be "".
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func apiVersionsToAPIGroup(apiVersions *unversioned.APIVersions) (apiGroup unversioned.APIGroup) {
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groupVersions := []unversioned.GroupVersionForDiscovery{}
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for _, version := range apiVersions.Versions {
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groupVersion := unversioned.GroupVersionForDiscovery{
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GroupVersion: version,
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Version: version,
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}
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groupVersions = append(groupVersions, groupVersion)
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}
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apiGroup.Versions = groupVersions
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// There should be only one groupVersion returned at /api
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apiGroup.PreferredVersion = groupVersions[0]
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return
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}
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// ServerGroups returns the supported groups, with information like supported versions and the
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// preferred version.
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func (d *DiscoveryClient) ServerGroups() (apiGroupList *unversioned.APIGroupList, err error) {
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// Get the groupVersions exposed at /api
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v := &unversioned.APIVersions{}
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err = d.Get().AbsPath(d.LegacyPrefix).Do().Into(v)
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apiGroup := unversioned.APIGroup{}
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if err == nil {
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apiGroup = apiVersionsToAPIGroup(v)
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}
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if err != nil && !errors.IsNotFound(err) && !errors.IsForbidden(err) {
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return nil, err
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}
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// Get the groupVersions exposed at /apis
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apiGroupList = &unversioned.APIGroupList{}
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err = d.Get().AbsPath("/apis").Do().Into(apiGroupList)
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if err != nil && !errors.IsNotFound(err) && !errors.IsForbidden(err) {
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return nil, err
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}
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// to be compatible with a v1.0 server, if it's a 403 or 404, ignore and return whatever we got from /api
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if err != nil && (errors.IsNotFound(err) || errors.IsForbidden(err)) {
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apiGroupList = &unversioned.APIGroupList{}
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}
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// append the group retrieved from /api to the list
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apiGroupList.Groups = append(apiGroupList.Groups, apiGroup)
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return apiGroupList, nil
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}
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// ServerResourcesForGroupVersion returns the supported resources for a group and version.
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func (d *DiscoveryClient) ServerResourcesForGroupVersion(groupVersion string) (resources *unversioned.APIResourceList, err error) {
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url := url.URL{}
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if len(groupVersion) == 0 {
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return nil, fmt.Errorf("groupVersion shouldn't be empty")
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}
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if len(d.LegacyPrefix) > 0 && groupVersion == "v1" {
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url.Path = d.LegacyPrefix + "/" + groupVersion
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} else {
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url.Path = "/apis/" + groupVersion
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}
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resources = &unversioned.APIResourceList{}
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err = d.Get().AbsPath(url.String()).Do().Into(resources)
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if err != nil {
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// ignore 403 or 404 error to be compatible with an v1.0 server.
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if groupVersion == "v1" && (errors.IsNotFound(err) || errors.IsForbidden(err)) {
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return resources, nil
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}
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return nil, err
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}
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return resources, nil
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}
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// ServerResources returns the supported resources for all groups and versions.
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func (d *DiscoveryClient) ServerResources() (map[string]*unversioned.APIResourceList, error) {
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apiGroups, err := d.ServerGroups()
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if err != nil {
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return nil, err
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}
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groupVersions := unversioned.ExtractGroupVersions(apiGroups)
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result := map[string]*unversioned.APIResourceList{}
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for _, groupVersion := range groupVersions {
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resources, err := d.ServerResourcesForGroupVersion(groupVersion)
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if err != nil {
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return nil, err
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}
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result[groupVersion] = resources
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}
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return result, nil
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}
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// ErrGroupDiscoveryFailed is returned if one or more API groups fail to load.
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type ErrGroupDiscoveryFailed struct {
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// Groups is a list of the groups that failed to load and the error cause
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Groups map[unversioned.GroupVersion]error
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}
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// Error implements the error interface
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func (e *ErrGroupDiscoveryFailed) Error() string {
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var groups []string
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for k, v := range e.Groups {
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groups = append(groups, fmt.Sprintf("%s: %v", k, v))
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}
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sort.Strings(groups)
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return fmt.Sprintf("unable to retrieve the complete list of server APIs: %s", strings.Join(groups, ", "))
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}
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// IsGroupDiscoveryFailedError returns true if the provided error indicates the server was unable to discover
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// a complete list of APIs for the client to use.
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func IsGroupDiscoveryFailedError(err error) bool {
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_, ok := err.(*ErrGroupDiscoveryFailed)
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return err != nil && ok
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}
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// serverPreferredResources returns the supported resources with the version preferred by the
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// server. If namespaced is true, only namespaced resources will be returned.
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func (d *DiscoveryClient) serverPreferredResources(namespaced bool) ([]unversioned.GroupVersionResource, error) {
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results := []unversioned.GroupVersionResource{}
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serverGroupList, err := d.ServerGroups()
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if err != nil {
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return results, err
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}
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var failedGroups map[unversioned.GroupVersion]error
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for _, apiGroup := range serverGroupList.Groups {
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preferredVersion := apiGroup.PreferredVersion
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groupVersion := unversioned.GroupVersion{Group: apiGroup.Name, Version: preferredVersion.Version}
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apiResourceList, err := d.ServerResourcesForGroupVersion(preferredVersion.GroupVersion)
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if err != nil {
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if failedGroups == nil {
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failedGroups = make(map[unversioned.GroupVersion]error)
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}
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failedGroups[groupVersion] = err
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continue
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}
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for _, apiResource := range apiResourceList.APIResources {
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// ignore the root scoped resources if "namespaced" is true.
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if namespaced && !apiResource.Namespaced {
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continue
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}
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if strings.Contains(apiResource.Name, "/") {
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continue
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}
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results = append(results, groupVersion.WithResource(apiResource.Name))
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}
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}
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if len(failedGroups) > 0 {
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return results, &ErrGroupDiscoveryFailed{Groups: failedGroups}
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}
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return results, nil
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}
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// ServerPreferredResources returns the supported resources with the version preferred by the
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// server.
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func (d *DiscoveryClient) ServerPreferredResources() ([]unversioned.GroupVersionResource, error) {
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return d.serverPreferredResources(false)
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}
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// ServerPreferredNamespacedResources returns the supported namespaced resources with the
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// version preferred by the server.
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func (d *DiscoveryClient) ServerPreferredNamespacedResources() ([]unversioned.GroupVersionResource, error) {
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return d.serverPreferredResources(true)
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}
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// ServerVersion retrieves and parses the server's version (git version).
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func (d *DiscoveryClient) ServerVersion() (*version.Info, error) {
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body, err := d.Get().AbsPath("/version").Do().Raw()
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if err != nil {
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return nil, err
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}
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var info version.Info
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err = json.Unmarshal(body, &info)
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if err != nil {
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return nil, fmt.Errorf("got '%s': %v", string(body), err)
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}
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return &info, nil
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}
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// SwaggerSchema retrieves and parses the swagger API schema the server supports.
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func (d *DiscoveryClient) SwaggerSchema(version unversioned.GroupVersion) (*swagger.ApiDeclaration, error) {
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if version.Empty() {
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return nil, fmt.Errorf("groupVersion cannot be empty")
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}
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groupList, err := d.ServerGroups()
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if err != nil {
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return nil, err
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}
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groupVersions := unversioned.ExtractGroupVersions(groupList)
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// This check also takes care the case that kubectl is newer than the running endpoint
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if stringDoesntExistIn(version.String(), groupVersions) {
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return nil, fmt.Errorf("API version: %v is not supported by the server. Use one of: %v", version, groupVersions)
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}
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var path string
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if len(d.LegacyPrefix) > 0 && version == v1.SchemeGroupVersion {
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path = "/swaggerapi" + d.LegacyPrefix + "/" + version.Version
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} else {
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path = "/swaggerapi/apis/" + version.Group + "/" + version.Version
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}
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body, err := d.Get().AbsPath(path).Do().Raw()
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if err != nil {
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return nil, err
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}
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var schema swagger.ApiDeclaration
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err = json.Unmarshal(body, &schema)
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if err != nil {
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return nil, fmt.Errorf("got '%s': %v", string(body), err)
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}
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return &schema, nil
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}
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func setDiscoveryDefaults(config *rest.Config) error {
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config.APIPath = ""
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config.GroupVersion = nil
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codec := runtime.NoopEncoder{Decoder: api.Codecs.UniversalDecoder()}
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config.NegotiatedSerializer = serializer.NegotiatedSerializerWrapper(
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runtime.SerializerInfo{Serializer: codec},
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runtime.StreamSerializerInfo{},
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)
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if len(config.UserAgent) == 0 {
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config.UserAgent = rest.DefaultKubernetesUserAgent()
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}
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return nil
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}
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// NewDiscoveryClientForConfig creates a new DiscoveryClient for the given config. This client
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// can be used to discover supported resources in the API server.
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func NewDiscoveryClientForConfig(c *rest.Config) (*DiscoveryClient, error) {
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config := *c
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if err := setDiscoveryDefaults(&config); err != nil {
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return nil, err
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}
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client, err := rest.UnversionedRESTClientFor(&config)
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return &DiscoveryClient{RESTClient: client, LegacyPrefix: "/api"}, err
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}
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// NewDiscoveryClientForConfig creates a new DiscoveryClient for the given config. If
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// there is an error, it panics.
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func NewDiscoveryClientForConfigOrDie(c *rest.Config) *DiscoveryClient {
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client, err := NewDiscoveryClientForConfig(c)
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if err != nil {
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panic(err)
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}
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return client
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}
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// New creates a new DiscoveryClient for the given RESTClient.
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func NewDiscoveryClient(c *rest.RESTClient) *DiscoveryClient {
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return &DiscoveryClient{RESTClient: c, LegacyPrefix: "/api"}
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}
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func stringDoesntExistIn(str string, slice []string) bool {
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for _, s := range slice {
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if s == str {
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return false
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}
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}
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return true
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}
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