Watch feature (#1527)

* Add part 1 watch functionality. (squashed) * add funcs for service/endpoint fqdns * add endpoints watch * document exposed funcs * only send subset deltas * locking for watch map * tests and docs * add pod watch * remove debugs prints * feedback part 1 * add error reporting to proto * inform clients of server stop+errors * add grpc options param * use proper context * Review feedback: * Removed client (will move to another repo) * Use new log functions * Change watchChan to be for string not []string * Rework how k8s plugin stores watch tracking info to simplify * Normalize the qname on watch request * Add blank line back * Revert another spurious change * Fix tests * Add stop channel. Fix tests. Better docs for plugin interface. * fmt.Printf -> log.Warningf * Move from dnsserver to plugin/pkg/watch * gofmt * remove dead client watches * sate linter * linter omg
2025-10-27 08:14:18 -04:00 · 2018-06-27 07:45:32 -07:00
parent b7480d5d12
commit 99287d091c
17 changed files with 980 additions and 60 deletions
--- a/pb/dns.pb.go
+++ b/pb/dns.pb.go
@@ -1,6 +1,5 @@
-// Code generated by protoc-gen-go.
+// Code generated by protoc-gen-go. DO NOT EDIT.
 // source: dns.proto
-// DO NOT EDIT!

 /*
 Package pb is a generated protocol buffer package.
@@ -10,6 +9,10 @@ It is generated from these files:

 It has these top-level messages:
 	DnsPacket
+	WatchRequest
+	WatchCreateRequest
+	WatchCancelRequest
+	WatchResponse
 */
 package pb

@@ -19,7 +22,6 @@ import math "math"

 import (
 	context "context"
-
 	grpc "google.golang.org/grpc"
 )

@@ -50,8 +52,223 @@ func (m *DnsPacket) GetMsg() []byte {
 	return nil
 }

+type WatchRequest struct {
+	// request_union is a request to either create a new watcher or cancel an existing watcher.
+	//
+	// Types that are valid to be assigned to RequestUnion:
+	//	*WatchRequest_CreateRequest
+	//	*WatchRequest_CancelRequest
+	RequestUnion isWatchRequest_RequestUnion `protobuf_oneof:"request_union"`
+}
+
+func (m *WatchRequest) Reset()                    { *m = WatchRequest{} }
+func (m *WatchRequest) String() string            { return proto.CompactTextString(m) }
+func (*WatchRequest) ProtoMessage()               {}
+func (*WatchRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
+
+type isWatchRequest_RequestUnion interface {
+	isWatchRequest_RequestUnion()
+}
+
+type WatchRequest_CreateRequest struct {
+	CreateRequest *WatchCreateRequest `protobuf:"bytes,1,opt,name=create_request,json=createRequest,oneof"`
+}
+type WatchRequest_CancelRequest struct {
+	CancelRequest *WatchCancelRequest `protobuf:"bytes,2,opt,name=cancel_request,json=cancelRequest,oneof"`
+}
+
+func (*WatchRequest_CreateRequest) isWatchRequest_RequestUnion() {}
+func (*WatchRequest_CancelRequest) isWatchRequest_RequestUnion() {}
+
+func (m *WatchRequest) GetRequestUnion() isWatchRequest_RequestUnion {
+	if m != nil {
+		return m.RequestUnion
+	}
+	return nil
+}
+
+func (m *WatchRequest) GetCreateRequest() *WatchCreateRequest {
+	if x, ok := m.GetRequestUnion().(*WatchRequest_CreateRequest); ok {
+		return x.CreateRequest
+	}
+	return nil
+}
+
+func (m *WatchRequest) GetCancelRequest() *WatchCancelRequest {
+	if x, ok := m.GetRequestUnion().(*WatchRequest_CancelRequest); ok {
+		return x.CancelRequest
+	}
+	return nil
+}
+
+// XXX_OneofFuncs is for the internal use of the proto package.
+func (*WatchRequest) XXX_OneofFuncs() (func(msg proto.Message, b *proto.Buffer) error, func(msg proto.Message, tag, wire int, b *proto.Buffer) (bool, error), func(msg proto.Message) (n int), []interface{}) {
+	return _WatchRequest_OneofMarshaler, _WatchRequest_OneofUnmarshaler, _WatchRequest_OneofSizer, []interface{}{
+		(*WatchRequest_CreateRequest)(nil),
+		(*WatchRequest_CancelRequest)(nil),
+	}
+}
+
+func _WatchRequest_OneofMarshaler(msg proto.Message, b *proto.Buffer) error {
+	m := msg.(*WatchRequest)
+	// request_union
+	switch x := m.RequestUnion.(type) {
+	case *WatchRequest_CreateRequest:
+		b.EncodeVarint(1<<3 | proto.WireBytes)
+		if err := b.EncodeMessage(x.CreateRequest); err != nil {
+			return err
+		}
+	case *WatchRequest_CancelRequest:
+		b.EncodeVarint(2<<3 | proto.WireBytes)
+		if err := b.EncodeMessage(x.CancelRequest); err != nil {
+			return err
+		}
+	case nil:
+	default:
+		return fmt.Errorf("WatchRequest.RequestUnion has unexpected type %T", x)
+	}
+	return nil
+}
+
+func _WatchRequest_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (bool, error) {
+	m := msg.(*WatchRequest)
+	switch tag {
+	case 1: // request_union.create_request
+		if wire != proto.WireBytes {
+			return true, proto.ErrInternalBadWireType
+		}
+		msg := new(WatchCreateRequest)
+		err := b.DecodeMessage(msg)
+		m.RequestUnion = &WatchRequest_CreateRequest{msg}
+		return true, err
+	case 2: // request_union.cancel_request
+		if wire != proto.WireBytes {
+			return true, proto.ErrInternalBadWireType
+		}
+		msg := new(WatchCancelRequest)
+		err := b.DecodeMessage(msg)
+		m.RequestUnion = &WatchRequest_CancelRequest{msg}
+		return true, err
+	default:
+		return false, nil
+	}
+}
+
+func _WatchRequest_OneofSizer(msg proto.Message) (n int) {
+	m := msg.(*WatchRequest)
+	// request_union
+	switch x := m.RequestUnion.(type) {
+	case *WatchRequest_CreateRequest:
+		s := proto.Size(x.CreateRequest)
+		n += proto.SizeVarint(1<<3 | proto.WireBytes)
+		n += proto.SizeVarint(uint64(s))
+		n += s
+	case *WatchRequest_CancelRequest:
+		s := proto.Size(x.CancelRequest)
+		n += proto.SizeVarint(2<<3 | proto.WireBytes)
+		n += proto.SizeVarint(uint64(s))
+		n += s
+	case nil:
+	default:
+		panic(fmt.Sprintf("proto: unexpected type %T in oneof", x))
+	}
+	return n
+}
+
+type WatchCreateRequest struct {
+	Query *DnsPacket `protobuf:"bytes,1,opt,name=query" json:"query,omitempty"`
+}
+
+func (m *WatchCreateRequest) Reset()                    { *m = WatchCreateRequest{} }
+func (m *WatchCreateRequest) String() string            { return proto.CompactTextString(m) }
+func (*WatchCreateRequest) ProtoMessage()               {}
+func (*WatchCreateRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{2} }
+
+func (m *WatchCreateRequest) GetQuery() *DnsPacket {
+	if m != nil {
+		return m.Query
+	}
+	return nil
+}
+
+type WatchCancelRequest struct {
+	// watch_id is the watcher id to cancel
+	WatchId int64 `protobuf:"varint,1,opt,name=watch_id,json=watchId" json:"watch_id,omitempty"`
+}
+
+func (m *WatchCancelRequest) Reset()                    { *m = WatchCancelRequest{} }
+func (m *WatchCancelRequest) String() string            { return proto.CompactTextString(m) }
+func (*WatchCancelRequest) ProtoMessage()               {}
+func (*WatchCancelRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{3} }
+
+func (m *WatchCancelRequest) GetWatchId() int64 {
+	if m != nil {
+		return m.WatchId
+	}
+	return 0
+}
+
+type WatchResponse struct {
+	// watch_id is the ID of the watcher that corresponds to the response.
+	WatchId int64 `protobuf:"varint,1,opt,name=watch_id,json=watchId" json:"watch_id,omitempty"`
+	// created is set to true if the response is for a create watch request.
+	// The client should record the watch_id and expect to receive DNS replies
+	// from the same stream.
+	// All replies sent to the created watcher will attach with the same watch_id.
+	Created bool `protobuf:"varint,2,opt,name=created" json:"created,omitempty"`
+	// canceled is set to true if the response is for a cancel watch request.
+	// No further events will be sent to the canceled watcher.
+	Canceled bool   `protobuf:"varint,3,opt,name=canceled" json:"canceled,omitempty"`
+	Qname    string `protobuf:"bytes,4,opt,name=qname" json:"qname,omitempty"`
+	Err      string `protobuf:"bytes,5,opt,name=err" json:"err,omitempty"`
+}
+
+func (m *WatchResponse) Reset()                    { *m = WatchResponse{} }
+func (m *WatchResponse) String() string            { return proto.CompactTextString(m) }
+func (*WatchResponse) ProtoMessage()               {}
+func (*WatchResponse) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{4} }
+
+func (m *WatchResponse) GetWatchId() int64 {
+	if m != nil {
+		return m.WatchId
+	}
+	return 0
+}
+
+func (m *WatchResponse) GetCreated() bool {
+	if m != nil {
+		return m.Created
+	}
+	return false
+}
+
+func (m *WatchResponse) GetCanceled() bool {
+	if m != nil {
+		return m.Canceled
+	}
+	return false
+}
+
+func (m *WatchResponse) GetQname() string {
+	if m != nil {
+		return m.Qname
+	}
+	return ""
+}
+
+func (m *WatchResponse) GetErr() string {
+	if m != nil {
+		return m.Err
+	}
+	return ""
+}
+
 func init() {
 	proto.RegisterType((*DnsPacket)(nil), "coredns.dns.DnsPacket")
+	proto.RegisterType((*WatchRequest)(nil), "coredns.dns.WatchRequest")
+	proto.RegisterType((*WatchCreateRequest)(nil), "coredns.dns.WatchCreateRequest")
+	proto.RegisterType((*WatchCancelRequest)(nil), "coredns.dns.WatchCancelRequest")
+	proto.RegisterType((*WatchResponse)(nil), "coredns.dns.WatchResponse")
 }

 // Reference imports to suppress errors if they are not otherwise used.
@@ -66,6 +283,7 @@ const _ = grpc.SupportPackageIsVersion4

 type DnsServiceClient interface {
 	Query(ctx context.Context, in *DnsPacket, opts ...grpc.CallOption) (*DnsPacket, error)
+	Watch(ctx context.Context, opts ...grpc.CallOption) (DnsService_WatchClient, error)
 }

 type dnsServiceClient struct {
@@ -85,10 +303,42 @@ func (c *dnsServiceClient) Query(ctx context.Context, in *DnsPacket, opts ...grp
 	return out, nil
 }

+func (c *dnsServiceClient) Watch(ctx context.Context, opts ...grpc.CallOption) (DnsService_WatchClient, error) {
+	stream, err := grpc.NewClientStream(ctx, &_DnsService_serviceDesc.Streams[0], c.cc, "/coredns.dns.DnsService/Watch", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &dnsServiceWatchClient{stream}
+	return x, nil
+}
+
+type DnsService_WatchClient interface {
+	Send(*WatchRequest) error
+	Recv() (*WatchResponse, error)
+	grpc.ClientStream
+}
+
+type dnsServiceWatchClient struct {
+	grpc.ClientStream
+}
+
+func (x *dnsServiceWatchClient) Send(m *WatchRequest) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *dnsServiceWatchClient) Recv() (*WatchResponse, error) {
+	m := new(WatchResponse)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
 // Server API for DnsService service

 type DnsServiceServer interface {
 	Query(context.Context, *DnsPacket) (*DnsPacket, error)
+	Watch(DnsService_WatchServer) error
 }

 func RegisterDnsServiceServer(s *grpc.Server, srv DnsServiceServer) {
@@ -113,6 +363,32 @@ func _DnsService_Query_Handler(srv interface{}, ctx context.Context, dec func(in
 	return interceptor(ctx, in, info, handler)
 }

+func _DnsService_Watch_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(DnsServiceServer).Watch(&dnsServiceWatchServer{stream})
+}
+
+type DnsService_WatchServer interface {
+	Send(*WatchResponse) error
+	Recv() (*WatchRequest, error)
+	grpc.ServerStream
+}
+
+type dnsServiceWatchServer struct {
+	grpc.ServerStream
+}
+
+func (x *dnsServiceWatchServer) Send(m *WatchResponse) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *dnsServiceWatchServer) Recv() (*WatchRequest, error) {
+	m := new(WatchRequest)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
 var _DnsService_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "coredns.dns.DnsService",
 	HandlerType: (*DnsServiceServer)(nil),
@@ -122,20 +398,40 @@ var _DnsService_serviceDesc = grpc.ServiceDesc{
 			Handler:    _DnsService_Query_Handler,
 		},
 	},
-	Streams:  []grpc.StreamDesc{},
+	Streams: []grpc.StreamDesc{
+		{
+			StreamName:    "Watch",
+			Handler:       _DnsService_Watch_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
+	},
 	Metadata: "dns.proto",
 }

 func init() { proto.RegisterFile("dns.proto", fileDescriptor0) }

 var fileDescriptor0 = []byte{
-	// 120 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0xe2, 0xe2, 0x4c, 0xc9, 0x2b, 0xd6,
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-	0xf5, 0xd1, 0x3f, 0x26, 0x8c, 0x00, 0x00, 0x00,
+	// 333 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x7c, 0x52, 0x41, 0x4f, 0x32, 0x31,
+	0x14, 0xfc, 0x0a, 0xec, 0x07, 0x3c, 0x40, 0xcd, 0x8b, 0x31, 0xcb, 0x26, 0x46, 0xb2, 0x27, 0x0e,
+	0x06, 0x0d, 0x1e, 0xbc, 0xaf, 0x1c, 0xf0, 0xa6, 0xf5, 0x60, 0xe2, 0x85, 0x2c, 0xdd, 0x17, 0x25,
+	0x4a, 0x17, 0xda, 0x45, 0xe3, 0x3f, 0xd0, 0xdf, 0xe3, 0x1f, 0x34, 0xfb, 0xba, 0x90, 0x35, 0x88,
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+	0xdc, 0x7e, 0x01, 0x9e, 0x82, 0xb7, 0x5c, 0x91, 0x79, 0x2f, 0x5e, 0x7c, 0xf4, 0xe3, 0x9e, 0x4d,
+	0x09, 0xd2, 0x89, 0xc2, 0xb3, 0xb5, 0x47, 0xf9, 0x2a, 0xec, 0x42, 0xe3, 0x2d, 0x67, 0x27, 0xb3,
+	0x84, 0x6d, 0xaa, 0xb2, 0xce, 0xf8, 0x3a, 0x09, 0x3f, 0x04, 0x74, 0x8a, 0xaa, 0xec, 0x22, 0xd5,
+	0x96, 0xfe, 0x10, 0xa3, 0x0f, 0x75, 0xd7, 0x46, 0xc2, 0xa9, 0x1b, 0x72, 0x0d, 0x31, 0x80, 0x86,
+	0x4b, 0x47, 0x89, 0x5f, 0xe5, 0xad, 0x0d, 0xc6, 0x43, 0xf0, 0x96, 0x3a, 0x9e, 0x93, 0x5f, 0xeb,
+	0x89, 0x7e, 0x53, 0x3a, 0x90, 0x4f, 0x8d, 0x8c, 0xf1, 0x3d, 0xe6, 0xf2, 0xe5, 0xf0, 0x53, 0x00,
+	0x8c, 0xb4, 0xbd, 0x23, 0xf3, 0x3a, 0x53, 0x84, 0x97, 0xe0, 0xdd, 0xe6, 0x99, 0x70, 0x47, 0xe4,
+	0x60, 0x07, 0x8f, 0x11, 0x78, 0x9c, 0x08, 0xbb, 0xdb, 0x33, 0x29, 0x1a, 0x09, 0x82, 0xdf, 0xb6,
+	0x5c, 0x01, 0x7d, 0x71, 0x2e, 0xa2, 0xda, 0x43, 0x65, 0x31, 0x9d, 0xfe, 0xe7, 0xaf, 0x77, 0xf1,
+	0x1d, 0x00, 0x00, 0xff, 0xff, 0xd2, 0x5b, 0x8c, 0xe1, 0x87, 0x02, 0x00, 0x00,
 }
--- a/pb/dns.proto
+++ b/pb/dns.proto
@@ -9,4 +9,41 @@ message DnsPacket {

 service DnsService {
 	rpc Query (DnsPacket) returns (DnsPacket);
+	rpc Watch (stream WatchRequest) returns (stream WatchResponse);
+}
+
+message WatchRequest {
+  // request_union is a request to either create a new watcher or cancel an existing watcher.
+  oneof request_union {
+    WatchCreateRequest create_request = 1;
+    WatchCancelRequest cancel_request = 2;
+  }
+}
+
+message WatchCreateRequest {
+  DnsPacket query = 1;
+}
+
+message WatchCancelRequest {
+  // watch_id is the watcher id to cancel
+  int64 watch_id = 1;
+}
+
+message WatchResponse {
+	// watch_id is the ID of the watcher that corresponds to the response.
+	int64 watch_id = 1;
+
+	// created is set to true if the response is for a create watch request.
+	// The client should record the watch_id and expect to receive DNS replies
+	// from the same stream.
+	// All replies sent to the created watcher will attach with the same watch_id.
+	bool created = 2;
+
+	// canceled is set to true if the response is for a cancel watch request.
+	// No further events will be sent to the canceled watcher.
+	bool canceled = 3;
+
+	string qname = 4;
+
+	string err = 5;
 }