Update federation target to etcd/clientv3 (#6119)

With CoreDNS now supporting etcdv3 as the DNS backend, we
can update our federation target to etcdv3. Users will now be
able to use etcdv3 server as the federation backbone.

Minio will update bucket data to etcdv3 and CoreDNS can pick
that data up and serve it as bucket style DNS path.

vendor/google.golang.org/grpc/status/go16.go

@@ -0,0 +1,42 @@
+// +build go1.6,!go1.7
+
+/*
+ *
+ * Copyright 2018 gRPC 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 status
+
+import (
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/codes"
+)
+
+// FromContextError converts a context error into a Status.  It returns a
+// Status with codes.OK if err is nil, or a Status with codes.Unknown if err is
+// non-nil and not a context error.
+func FromContextError(err error) *Status {
+	switch err {
+	case nil:
+		return New(codes.OK, "")
+	case context.DeadlineExceeded:
+		return New(codes.DeadlineExceeded, err.Error())
+	case context.Canceled:
+		return New(codes.Canceled, err.Error())
+	default:
+		return New(codes.Unknown, err.Error())
+	}
+}

vendor/google.golang.org/grpc/status/go17.go

@@ -0,0 +1,44 @@
+// +build go1.7
+
+/*
+ *
+ * Copyright 2018 gRPC 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 status
+
+import (
+	"context"
+
+	netctx "golang.org/x/net/context"
+	"google.golang.org/grpc/codes"
+)
+
+// FromContextError converts a context error into a Status.  It returns a
+// Status with codes.OK if err is nil, or a Status with codes.Unknown if err is
+// non-nil and not a context error.
+func FromContextError(err error) *Status {
+	switch err {
+	case nil:
+		return New(codes.OK, "")
+	case context.DeadlineExceeded, netctx.DeadlineExceeded:
+		return New(codes.DeadlineExceeded, err.Error())
+	case context.Canceled, netctx.Canceled:
+		return New(codes.Canceled, err.Error())
+	default:
+		return New(codes.Unknown, err.Error())
+	}
+}

vendor/google.golang.org/grpc/status/status.go

@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * 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
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 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.
  *
  */
 
@@ -43,9 +28,11 @@
 package status
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
 	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
 )
@@ -59,7 +46,7 @@ func (se *statusError) Error() string {
 	return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
 }
 
-func (se *statusError) status() *Status {
+func (se *statusError) GRPCStatus() *Status {
 	return &Status{s: (*spb.Status)(se)}
 }
 
@@ -133,13 +120,70 @@ func FromProto(s *spb.Status) *Status {
 }
 
 // FromError returns a Status representing err if it was produced from this
-// package, otherwise it returns nil, false.
+// package or has a method `GRPCStatus() *Status`. Otherwise, ok is false and a
+// Status is returned with codes.Unknown and the original error message.
 func FromError(err error) (s *Status, ok bool) {
 	if err == nil {
 		return &Status{s: &spb.Status{Code: int32(codes.OK)}}, true
 	}
-	if s, ok := err.(*statusError); ok {
-		return s.status(), true
+	if se, ok := err.(interface{ GRPCStatus() *Status }); ok {
+		return se.GRPCStatus(), true
 	}
-	return nil, false
+	return New(codes.Unknown, err.Error()), false
+}
+
+// Convert is a convenience function which removes the need to handle the
+// boolean return value from FromError.
+func Convert(err error) *Status {
+	s, _ := FromError(err)
+	return s
+}
+
+// WithDetails returns a new status with the provided details messages appended to the status.
+// If any errors are encountered, it returns nil and the first error encountered.
+func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
+	if s.Code() == codes.OK {
+		return nil, errors.New("no error details for status with code OK")
+	}
+	// s.Code() != OK implies that s.Proto() != nil.
+	p := s.Proto()
+	for _, detail := range details {
+		any, err := ptypes.MarshalAny(detail)
+		if err != nil {
+			return nil, err
+		}
+		p.Details = append(p.Details, any)
+	}
+	return &Status{s: p}, nil
+}
+
+// Details returns a slice of details messages attached to the status.
+// If a detail cannot be decoded, the error is returned in place of the detail.
+func (s *Status) Details() []interface{} {
+	if s == nil || s.s == nil {
+		return nil
+	}
+	details := make([]interface{}, 0, len(s.s.Details))
+	for _, any := range s.s.Details {
+		detail := &ptypes.DynamicAny{}
+		if err := ptypes.UnmarshalAny(any, detail); err != nil {
+			details = append(details, err)
+			continue
+		}
+		details = append(details, detail.Message)
+	}
+	return details
+}
+
+// Code returns the Code of the error if it is a Status error, codes.OK if err
+// is nil, or codes.Unknown otherwise.
+func Code(err error) codes.Code {
+	// Don't use FromError to avoid allocation of OK status.
+	if err == nil {
+		return codes.OK
+	}
+	if se, ok := err.(interface{ GRPCStatus() *Status }); ok {
+		return se.GRPCStatus().Code()
+	}
+	return codes.Unknown
 }