vendor: revendor metrics-server, custom-metrics-apiserver

vendor/go.etcd.io/etcd/clientv3/ctx.go

@@ -0,0 +1,64 @@
+// Copyright 2020 The etcd 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 clientv3
+
+import (
+	"context"
+	"strings"
+
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	"go.etcd.io/etcd/version"
+	"google.golang.org/grpc/metadata"
+)
+
+// WithRequireLeader requires client requests to only succeed
+// when the cluster has a leader.
+func WithRequireLeader(ctx context.Context) context.Context {
+	md, ok := metadata.FromOutgoingContext(ctx)
+	if !ok { // no outgoing metadata ctx key, create one
+		md = metadata.Pairs(rpctypes.MetadataRequireLeaderKey, rpctypes.MetadataHasLeader)
+		return metadata.NewOutgoingContext(ctx, md)
+	}
+	copied := md.Copy() // avoid racey updates
+	// overwrite/add 'hasleader' key/value
+	metadataSet(copied, rpctypes.MetadataRequireLeaderKey, rpctypes.MetadataHasLeader)
+	return metadata.NewOutgoingContext(ctx, copied)
+}
+
+// embeds client version
+func withVersion(ctx context.Context) context.Context {
+	md, ok := metadata.FromOutgoingContext(ctx)
+	if !ok { // no outgoing metadata ctx key, create one
+		md = metadata.Pairs(rpctypes.MetadataClientAPIVersionKey, version.APIVersion)
+		return metadata.NewOutgoingContext(ctx, md)
+	}
+	copied := md.Copy() // avoid racey updates
+	// overwrite/add version key/value
+	metadataSet(copied, rpctypes.MetadataClientAPIVersionKey, version.APIVersion)
+	return metadata.NewOutgoingContext(ctx, copied)
+}
+
+func metadataGet(md metadata.MD, k string) []string {
+	k = strings.ToLower(k)
+	return md[k]
+}
+
+func metadataSet(md metadata.MD, k string, vals ...string) {
+	if len(vals) == 0 {
+		return
+	}
+	k = strings.ToLower(k)
+	md[k] = vals
+}