[VOL-1866] Changed module dependency to v12.0.0 of k8s client-go and v1.15.4 of k8s api/apimachinery in sync with other voltha components

Had to use pseudo-version corresponding to v12.0.0 of k8s client-go
because golang proxy is no longer serving the modules not complying
to Semantic Import Versioning rules including client-go v12.0.0.
Refer to https://github.com/kubernetes/client-go/issues/631 and
https://github.com/golang/go/issues/33558

Change-Id: I2e558bab7f0702f230761319eb5392a7d0532ea3
diff --git a/vendor/k8s.io/client-go/discovery/cached_discovery.go b/vendor/k8s.io/client-go/discovery/cached_discovery.go
deleted file mode 100644
index df69d6a..0000000
--- a/vendor/k8s.io/client-go/discovery/cached_discovery.go
+++ /dev/null
@@ -1,295 +0,0 @@
-/*
-Copyright 2016 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 discovery
-
-import (
-	"errors"
-	"io/ioutil"
-	"net/http"
-	"os"
-	"path/filepath"
-	"sync"
-	"time"
-
-	"github.com/googleapis/gnostic/OpenAPIv2"
-	"k8s.io/klog"
-
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/version"
-	"k8s.io/client-go/kubernetes/scheme"
-	restclient "k8s.io/client-go/rest"
-)
-
-// CachedDiscoveryClient implements the functions that discovery server-supported API groups,
-// versions and resources.
-type CachedDiscoveryClient struct {
-	delegate DiscoveryInterface
-
-	// cacheDirectory is the directory where discovery docs are held.  It must be unique per host:port combination to work well.
-	cacheDirectory string
-
-	// ttl is how long the cache should be considered valid
-	ttl time.Duration
-
-	// mutex protects the variables below
-	mutex sync.Mutex
-
-	// ourFiles are all filenames of cache files created by this process
-	ourFiles map[string]struct{}
-	// invalidated is true if all cache files should be ignored that are not ours (e.g. after Invalidate() was called)
-	invalidated bool
-	// fresh is true if all used cache files were ours
-	fresh bool
-}
-
-var _ CachedDiscoveryInterface = &CachedDiscoveryClient{}
-
-// ServerResourcesForGroupVersion returns the supported resources for a group and version.
-func (d *CachedDiscoveryClient) ServerResourcesForGroupVersion(groupVersion string) (*metav1.APIResourceList, error) {
-	filename := filepath.Join(d.cacheDirectory, groupVersion, "serverresources.json")
-	cachedBytes, err := d.getCachedFile(filename)
-	// don't fail on errors, we either don't have a file or won't be able to run the cached check. Either way we can fallback.
-	if err == nil {
-		cachedResources := &metav1.APIResourceList{}
-		if err := runtime.DecodeInto(scheme.Codecs.UniversalDecoder(), cachedBytes, cachedResources); err == nil {
-			klog.V(10).Infof("returning cached discovery info from %v", filename)
-			return cachedResources, nil
-		}
-	}
-
-	liveResources, err := d.delegate.ServerResourcesForGroupVersion(groupVersion)
-	if err != nil {
-		klog.V(3).Infof("skipped caching discovery info due to %v", err)
-		return liveResources, err
-	}
-	if liveResources == nil || len(liveResources.APIResources) == 0 {
-		klog.V(3).Infof("skipped caching discovery info, no resources found")
-		return liveResources, err
-	}
-
-	if err := d.writeCachedFile(filename, liveResources); err != nil {
-		klog.V(1).Infof("failed to write cache to %v due to %v", filename, err)
-	}
-
-	return liveResources, nil
-}
-
-// ServerResources returns the supported resources for all groups and versions.
-func (d *CachedDiscoveryClient) ServerResources() ([]*metav1.APIResourceList, error) {
-	return ServerResources(d)
-}
-
-// ServerGroups returns the supported groups, with information like supported versions and the
-// preferred version.
-func (d *CachedDiscoveryClient) ServerGroups() (*metav1.APIGroupList, error) {
-	filename := filepath.Join(d.cacheDirectory, "servergroups.json")
-	cachedBytes, err := d.getCachedFile(filename)
-	// don't fail on errors, we either don't have a file or won't be able to run the cached check. Either way we can fallback.
-	if err == nil {
-		cachedGroups := &metav1.APIGroupList{}
-		if err := runtime.DecodeInto(scheme.Codecs.UniversalDecoder(), cachedBytes, cachedGroups); err == nil {
-			klog.V(10).Infof("returning cached discovery info from %v", filename)
-			return cachedGroups, nil
-		}
-	}
-
-	liveGroups, err := d.delegate.ServerGroups()
-	if err != nil {
-		klog.V(3).Infof("skipped caching discovery info due to %v", err)
-		return liveGroups, err
-	}
-	if liveGroups == nil || len(liveGroups.Groups) == 0 {
-		klog.V(3).Infof("skipped caching discovery info, no groups found")
-		return liveGroups, err
-	}
-
-	if err := d.writeCachedFile(filename, liveGroups); err != nil {
-		klog.V(1).Infof("failed to write cache to %v due to %v", filename, err)
-	}
-
-	return liveGroups, nil
-}
-
-func (d *CachedDiscoveryClient) getCachedFile(filename string) ([]byte, error) {
-	// after invalidation ignore cache files not created by this process
-	d.mutex.Lock()
-	_, ourFile := d.ourFiles[filename]
-	if d.invalidated && !ourFile {
-		d.mutex.Unlock()
-		return nil, errors.New("cache invalidated")
-	}
-	d.mutex.Unlock()
-
-	file, err := os.Open(filename)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-
-	fileInfo, err := file.Stat()
-	if err != nil {
-		return nil, err
-	}
-
-	if time.Now().After(fileInfo.ModTime().Add(d.ttl)) {
-		return nil, errors.New("cache expired")
-	}
-
-	// the cache is present and its valid.  Try to read and use it.
-	cachedBytes, err := ioutil.ReadAll(file)
-	if err != nil {
-		return nil, err
-	}
-
-	d.mutex.Lock()
-	defer d.mutex.Unlock()
-	d.fresh = d.fresh && ourFile
-
-	return cachedBytes, nil
-}
-
-func (d *CachedDiscoveryClient) writeCachedFile(filename string, obj runtime.Object) error {
-	if err := os.MkdirAll(filepath.Dir(filename), 0755); err != nil {
-		return err
-	}
-
-	bytes, err := runtime.Encode(scheme.Codecs.LegacyCodec(), obj)
-	if err != nil {
-		return err
-	}
-
-	f, err := ioutil.TempFile(filepath.Dir(filename), filepath.Base(filename)+".")
-	if err != nil {
-		return err
-	}
-	defer os.Remove(f.Name())
-	_, err = f.Write(bytes)
-	if err != nil {
-		return err
-	}
-
-	err = os.Chmod(f.Name(), 0755)
-	if err != nil {
-		return err
-	}
-
-	name := f.Name()
-	err = f.Close()
-	if err != nil {
-		return err
-	}
-
-	// atomic rename
-	d.mutex.Lock()
-	defer d.mutex.Unlock()
-	err = os.Rename(name, filename)
-	if err == nil {
-		d.ourFiles[filename] = struct{}{}
-	}
-	return err
-}
-
-// RESTClient returns a RESTClient that is used to communicate with API server
-// by this client implementation.
-func (d *CachedDiscoveryClient) RESTClient() restclient.Interface {
-	return d.delegate.RESTClient()
-}
-
-// ServerPreferredResources returns the supported resources with the version preferred by the
-// server.
-func (d *CachedDiscoveryClient) ServerPreferredResources() ([]*metav1.APIResourceList, error) {
-	return ServerPreferredResources(d)
-}
-
-// ServerPreferredNamespacedResources returns the supported namespaced resources with the
-// version preferred by the server.
-func (d *CachedDiscoveryClient) ServerPreferredNamespacedResources() ([]*metav1.APIResourceList, error) {
-	return ServerPreferredNamespacedResources(d)
-}
-
-// ServerVersion retrieves and parses the server's version (git version).
-func (d *CachedDiscoveryClient) ServerVersion() (*version.Info, error) {
-	return d.delegate.ServerVersion()
-}
-
-// OpenAPISchema retrieves and parses the swagger API schema the server supports.
-func (d *CachedDiscoveryClient) OpenAPISchema() (*openapi_v2.Document, error) {
-	return d.delegate.OpenAPISchema()
-}
-
-// Fresh is supposed to tell the caller whether or not to retry if the cache
-// fails to find something (false = retry, true = no need to retry).
-func (d *CachedDiscoveryClient) Fresh() bool {
-	d.mutex.Lock()
-	defer d.mutex.Unlock()
-
-	return d.fresh
-}
-
-// Invalidate enforces that no cached data is used in the future that is older than the current time.
-func (d *CachedDiscoveryClient) Invalidate() {
-	d.mutex.Lock()
-	defer d.mutex.Unlock()
-
-	d.ourFiles = map[string]struct{}{}
-	d.fresh = true
-	d.invalidated = true
-}
-
-// NewCachedDiscoveryClientForConfig creates a new DiscoveryClient for the given config, and wraps
-// the created client in a CachedDiscoveryClient. The provided configuration is updated with a
-// custom transport that understands cache responses.
-// We receive two distinct cache directories for now, in order to preserve old behavior
-// which makes use of the --cache-dir flag value for storing cache data from the CacheRoundTripper,
-// and makes use of the hardcoded destination (~/.kube/cache/discovery/...) for storing
-// CachedDiscoveryClient cache data. If httpCacheDir is empty, the restconfig's transport will not
-// be updated with a roundtripper that understands cache responses.
-// If discoveryCacheDir is empty, cached server resource data will be looked up in the current directory.
-// TODO(juanvallejo): the value of "--cache-dir" should be honored. Consolidate discoveryCacheDir with httpCacheDir
-// so that server resources and http-cache data are stored in the same location, provided via config flags.
-func NewCachedDiscoveryClientForConfig(config *restclient.Config, discoveryCacheDir, httpCacheDir string, ttl time.Duration) (*CachedDiscoveryClient, error) {
-	if len(httpCacheDir) > 0 {
-		// update the given restconfig with a custom roundtripper that
-		// understands how to handle cache responses.
-		wt := config.WrapTransport
-		config.WrapTransport = func(rt http.RoundTripper) http.RoundTripper {
-			if wt != nil {
-				rt = wt(rt)
-			}
-			return newCacheRoundTripper(httpCacheDir, rt)
-		}
-	}
-
-	discoveryClient, err := NewDiscoveryClientForConfig(config)
-	if err != nil {
-		return nil, err
-	}
-
-	return newCachedDiscoveryClient(discoveryClient, discoveryCacheDir, ttl), nil
-}
-
-// NewCachedDiscoveryClient creates a new DiscoveryClient.  cacheDirectory is the directory where discovery docs are held.  It must be unique per host:port combination to work well.
-func newCachedDiscoveryClient(delegate DiscoveryInterface, cacheDirectory string, ttl time.Duration) *CachedDiscoveryClient {
-	return &CachedDiscoveryClient{
-		delegate:       delegate,
-		cacheDirectory: cacheDirectory,
-		ttl:            ttl,
-		ourFiles:       map[string]struct{}{},
-		fresh:          true,
-	}
-}
diff --git a/vendor/k8s.io/client-go/discovery/discovery_client.go b/vendor/k8s.io/client-go/discovery/discovery_client.go
index 17b39de..61b9c44 100644
--- a/vendor/k8s.io/client-go/discovery/discovery_client.go
+++ b/vendor/k8s.io/client-go/discovery/discovery_client.go
@@ -26,7 +26,7 @@
 	"time"
 
 	"github.com/golang/protobuf/proto"
-	"github.com/googleapis/gnostic/OpenAPIv2"
+	openapi_v2 "github.com/googleapis/gnostic/OpenAPIv2"
 
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -60,6 +60,9 @@
 }
 
 // CachedDiscoveryInterface is a DiscoveryInterface with cache invalidation and freshness.
+// Note that If the ServerResourcesForGroupVersion method returns a cache miss
+// error, the user needs to explicitly call Invalidate to clear the cache,
+// otherwise the same cache miss error will be returned next time.
 type CachedDiscoveryInterface interface {
 	DiscoveryInterface
 	// Fresh is supposed to tell the caller whether or not to retry if the cache
@@ -68,7 +71,8 @@
 	// TODO: this needs to be revisited, this interface can't be locked properly
 	// and doesn't make a lot of sense.
 	Fresh() bool
-	// Invalidate enforces that no cached data is used in the future that is older than the current time.
+	// Invalidate enforces that no cached data that is older than the current time
+	// is used.
 	Invalidate()
 }
 
@@ -84,12 +88,28 @@
 	// ServerResourcesForGroupVersion returns the supported resources for a group and version.
 	ServerResourcesForGroupVersion(groupVersion string) (*metav1.APIResourceList, error)
 	// ServerResources returns the supported resources for all groups and versions.
+	//
+	// The returned resource list might be non-nil with partial results even in the case of
+	// non-nil error.
+	//
+	// Deprecated: use ServerGroupsAndResources instead.
 	ServerResources() ([]*metav1.APIResourceList, error)
+	// ServerResources returns the supported groups and resources for all groups and versions.
+	//
+	// The returned group and resource lists might be non-nil with partial results even in the
+	// case of non-nil error.
+	ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error)
 	// ServerPreferredResources returns the supported resources with the version preferred by the
 	// server.
+	//
+	// The returned group and resource lists might be non-nil with partial results even in the
+	// case of non-nil error.
 	ServerPreferredResources() ([]*metav1.APIResourceList, error)
 	// ServerPreferredNamespacedResources returns the supported namespaced resources with the
 	// version preferred by the server.
+	//
+	// The returned resource list might be non-nil with partial results even in the case of
+	// non-nil error.
 	ServerPreferredNamespacedResources() ([]*metav1.APIResourceList, error)
 }
 
@@ -187,14 +207,18 @@
 	return resources, nil
 }
 
-// serverResources returns the supported resources for all groups and versions.
-func (d *DiscoveryClient) serverResources() ([]*metav1.APIResourceList, error) {
-	return ServerResources(d)
+// ServerResources returns the supported resources for all groups and versions.
+// Deprecated: use ServerGroupsAndResources instead.
+func (d *DiscoveryClient) ServerResources() ([]*metav1.APIResourceList, error) {
+	_, rs, err := d.ServerGroupsAndResources()
+	return rs, err
 }
 
-// ServerResources returns the supported resources for all groups and versions.
-func (d *DiscoveryClient) ServerResources() ([]*metav1.APIResourceList, error) {
-	return withRetries(defaultRetries, d.serverResources)
+// ServerGroupsAndResources returns the supported resources for all groups and versions.
+func (d *DiscoveryClient) ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	return withRetries(defaultRetries, func() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+		return ServerGroupsAndResources(d)
+	})
 }
 
 // ErrGroupDiscoveryFailed is returned if one or more API groups fail to load.
@@ -220,23 +244,28 @@
 	return err != nil && ok
 }
 
-// serverPreferredResources returns the supported resources with the version preferred by the server.
-func (d *DiscoveryClient) serverPreferredResources() ([]*metav1.APIResourceList, error) {
-	return ServerPreferredResources(d)
+// ServerResources uses the provided discovery interface to look up supported resources for all groups and versions.
+// Deprecated: use ServerGroupsAndResources instead.
+func ServerResources(d DiscoveryInterface) ([]*metav1.APIResourceList, error) {
+	_, rs, err := ServerGroupsAndResources(d)
+	return rs, err
 }
 
-// ServerResources uses the provided discovery interface to look up supported resources for all groups and versions.
-func ServerResources(d DiscoveryInterface) ([]*metav1.APIResourceList, error) {
-	apiGroups, err := d.ServerGroups()
-	if err != nil {
-		return nil, err
+func ServerGroupsAndResources(d DiscoveryInterface) ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	sgs, err := d.ServerGroups()
+	if sgs == nil {
+		return nil, nil, err
+	}
+	resultGroups := []*metav1.APIGroup{}
+	for i := range sgs.Groups {
+		resultGroups = append(resultGroups, &sgs.Groups[i])
 	}
 
-	groupVersionResources, failedGroups := fetchGroupVersionResources(d, apiGroups)
+	groupVersionResources, failedGroups := fetchGroupVersionResources(d, sgs)
 
 	// order results by group/version discovery order
 	result := []*metav1.APIResourceList{}
-	for _, apiGroup := range apiGroups.Groups {
+	for _, apiGroup := range sgs.Groups {
 		for _, version := range apiGroup.Versions {
 			gv := schema.GroupVersion{Group: apiGroup.Name, Version: version.Version}
 			if resources, ok := groupVersionResources[gv]; ok {
@@ -246,10 +275,10 @@
 	}
 
 	if len(failedGroups) == 0 {
-		return result, nil
+		return resultGroups, result, nil
 	}
 
-	return result, &ErrGroupDiscoveryFailed{Groups: failedGroups}
+	return resultGroups, result, &ErrGroupDiscoveryFailed{Groups: failedGroups}
 }
 
 // ServerPreferredResources uses the provided discovery interface to look up preferred resources
@@ -313,7 +342,7 @@
 	return result, &ErrGroupDiscoveryFailed{Groups: failedGroups}
 }
 
-// fetchServerResourcesForGroupVersions uses the discovery client to fetch the resources for the specified groups in parallel
+// fetchServerResourcesForGroupVersions uses the discovery client to fetch the resources for the specified groups in parallel.
 func fetchGroupVersionResources(d DiscoveryInterface, apiGroups *metav1.APIGroupList) (map[schema.GroupVersion]*metav1.APIResourceList, map[schema.GroupVersion]error) {
 	groupVersionResources := make(map[schema.GroupVersion]*metav1.APIResourceList)
 	failedGroups := make(map[schema.GroupVersion]error)
@@ -337,7 +366,9 @@
 				if err != nil {
 					// TODO: maybe restrict this to NotFound errors
 					failedGroups[groupVersion] = err
-				} else {
+				}
+				if apiResourceList != nil {
+					// even in case of error, some fallback might have been returned
 					groupVersionResources[groupVersion] = apiResourceList
 				}
 			}()
@@ -351,7 +382,11 @@
 // ServerPreferredResources returns the supported resources with the version preferred by the
 // server.
 func (d *DiscoveryClient) ServerPreferredResources() ([]*metav1.APIResourceList, error) {
-	return withRetries(defaultRetries, d.serverPreferredResources)
+	_, rs, err := withRetries(defaultRetries, func() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+		rs, err := ServerPreferredResources(d)
+		return nil, rs, err
+	})
+	return rs, err
 }
 
 // ServerPreferredNamespacedResources returns the supported namespaced resources with the
@@ -377,7 +412,7 @@
 	var info version.Info
 	err = json.Unmarshal(body, &info)
 	if err != nil {
-		return nil, fmt.Errorf("got '%s': %v", string(body), err)
+		return nil, fmt.Errorf("unable to parse the server version: %v", err)
 	}
 	return &info, nil
 }
@@ -388,7 +423,7 @@
 	if err != nil {
 		if errors.IsForbidden(err) || errors.IsNotFound(err) || errors.IsNotAcceptable(err) {
 			// single endpoint not found/registered in old server, try to fetch old endpoint
-			// TODO(roycaihw): remove this in 1.11
+			// TODO: remove this when kubectl/client-go don't work with 1.9 server
 			data, err = d.restClient.Get().AbsPath("/swagger-2.0.0.pb-v1").Do().Raw()
 			if err != nil {
 				return nil, err
@@ -406,19 +441,20 @@
 }
 
 // withRetries retries the given recovery function in case the groups supported by the server change after ServerGroup() returns.
-func withRetries(maxRetries int, f func() ([]*metav1.APIResourceList, error)) ([]*metav1.APIResourceList, error) {
+func withRetries(maxRetries int, f func() ([]*metav1.APIGroup, []*metav1.APIResourceList, error)) ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
 	var result []*metav1.APIResourceList
+	var resultGroups []*metav1.APIGroup
 	var err error
 	for i := 0; i < maxRetries; i++ {
-		result, err = f()
+		resultGroups, result, err = f()
 		if err == nil {
-			return result, nil
+			return resultGroups, result, nil
 		}
 		if _, ok := err.(*ErrGroupDiscoveryFailed); !ok {
-			return nil, err
+			return nil, nil, err
 		}
 	}
-	return result, err
+	return resultGroups, result, err
 }
 
 func setDiscoveryDefaults(config *restclient.Config) error {
diff --git a/vendor/k8s.io/client-go/discovery/round_tripper.go b/vendor/k8s.io/client-go/discovery/round_tripper.go
deleted file mode 100644
index 4e2bc24..0000000
--- a/vendor/k8s.io/client-go/discovery/round_tripper.go
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
-Copyright 2017 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 discovery
-
-import (
-	"net/http"
-	"path/filepath"
-
-	"github.com/gregjones/httpcache"
-	"github.com/gregjones/httpcache/diskcache"
-	"github.com/peterbourgon/diskv"
-	"k8s.io/klog"
-)
-
-type cacheRoundTripper struct {
-	rt *httpcache.Transport
-}
-
-// newCacheRoundTripper creates a roundtripper that reads the ETag on
-// response headers and send the If-None-Match header on subsequent
-// corresponding requests.
-func newCacheRoundTripper(cacheDir string, rt http.RoundTripper) http.RoundTripper {
-	d := diskv.New(diskv.Options{
-		BasePath: cacheDir,
-		TempDir:  filepath.Join(cacheDir, ".diskv-temp"),
-	})
-	t := httpcache.NewTransport(diskcache.NewWithDiskv(d))
-	t.Transport = rt
-
-	return &cacheRoundTripper{rt: t}
-}
-
-func (rt *cacheRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	return rt.rt.RoundTrip(req)
-}
-
-func (rt *cacheRoundTripper) CancelRequest(req *http.Request) {
-	type canceler interface {
-		CancelRequest(*http.Request)
-	}
-	if cr, ok := rt.rt.Transport.(canceler); ok {
-		cr.CancelRequest(req)
-	} else {
-		klog.Errorf("CancelRequest not implemented by %T", rt.rt.Transport)
-	}
-}
-
-func (rt *cacheRoundTripper) WrappedRoundTripper() http.RoundTripper { return rt.rt.Transport }