Add grpc health check service

Fixes: #615

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

cmd/containerd/builtins.go

@@ -5,6 +5,7 @@ import (
 	_ "github.com/docker/containerd/linux"
 	_ "github.com/docker/containerd/services/content"
 	_ "github.com/docker/containerd/services/execution"
+	_ "github.com/docker/containerd/services/healthcheck"
 	_ "github.com/docker/containerd/snapshot/btrfs"
 	_ "github.com/docker/containerd/snapshot/overlay"
 )

cmd/containerd/main.go

@@ -125,6 +125,7 @@ func main() {
 				return err
 			}
 		}
+		log.G(global).Info("starting GRPC API server...")
 		if err := serveGRPC(server); err != nil {
 			return err
 		}

services/healthcheck/service.go

@@ -0,0 +1,31 @@
+package healthcheck
+
+import (
+	"github.com/docker/containerd/plugin"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/health"
+	"google.golang.org/grpc/health/grpc_health_v1"
+)
+
+type Service struct {
+	serve *health.Server
+}
+
+func init() {
+	plugin.Register("healthcheck-grpc", &plugin.Registration{
+		Type: plugin.GRPCPlugin,
+		Init: NewService,
+	})
+}
+
+func NewService(ic *plugin.InitContext) (interface{}, error) {
+	return &Service{
+		health.NewServer(),
+	}, nil
+}
+
+func (s *Service) Register(server *grpc.Server) error {
+	grpc_health_v1.RegisterHealthServer(server, s.serve)
+	return nil
+}

vendor/google.golang.org/grpc/health/grpc_health_v1/health.pb.go

@@ -0,0 +1,176 @@
+// Code generated by protoc-gen-go.
+// source: health.proto
+// DO NOT EDIT!
+
+/*
+Package grpc_health_v1 is a generated protocol buffer package.
+
+It is generated from these files:
+	health.proto
+
+It has these top-level messages:
+	HealthCheckRequest
+	HealthCheckResponse
+*/
+package grpc_health_v1
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+import (
+	context "golang.org/x/net/context"
+	grpc "google.golang.org/grpc"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type HealthCheckResponse_ServingStatus int32
+
+const (
+	HealthCheckResponse_UNKNOWN     HealthCheckResponse_ServingStatus = 0
+	HealthCheckResponse_SERVING     HealthCheckResponse_ServingStatus = 1
+	HealthCheckResponse_NOT_SERVING HealthCheckResponse_ServingStatus = 2
+)
+
+var HealthCheckResponse_ServingStatus_name = map[int32]string{
+	0: "UNKNOWN",
+	1: "SERVING",
+	2: "NOT_SERVING",
+}
+var HealthCheckResponse_ServingStatus_value = map[string]int32{
+	"UNKNOWN":     0,
+	"SERVING":     1,
+	"NOT_SERVING": 2,
+}
+
+func (x HealthCheckResponse_ServingStatus) String() string {
+	return proto.EnumName(HealthCheckResponse_ServingStatus_name, int32(x))
+}
+func (HealthCheckResponse_ServingStatus) EnumDescriptor() ([]byte, []int) {
+	return fileDescriptor0, []int{1, 0}
+}
+
+type HealthCheckRequest struct {
+	Service string `protobuf:"bytes,1,opt,name=service" json:"service,omitempty"`
+}
+
+func (m *HealthCheckRequest) Reset()                    { *m = HealthCheckRequest{} }
+func (m *HealthCheckRequest) String() string            { return proto.CompactTextString(m) }
+func (*HealthCheckRequest) ProtoMessage()               {}
+func (*HealthCheckRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
+
+type HealthCheckResponse struct {
+	Status HealthCheckResponse_ServingStatus `protobuf:"varint,1,opt,name=status,enum=grpc.health.v1.HealthCheckResponse_ServingStatus" json:"status,omitempty"`
+}
+
+func (m *HealthCheckResponse) Reset()                    { *m = HealthCheckResponse{} }
+func (m *HealthCheckResponse) String() string            { return proto.CompactTextString(m) }
+func (*HealthCheckResponse) ProtoMessage()               {}
+func (*HealthCheckResponse) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
+
+func init() {
+	proto.RegisterType((*HealthCheckRequest)(nil), "grpc.health.v1.HealthCheckRequest")
+	proto.RegisterType((*HealthCheckResponse)(nil), "grpc.health.v1.HealthCheckResponse")
+	proto.RegisterEnum("grpc.health.v1.HealthCheckResponse_ServingStatus", HealthCheckResponse_ServingStatus_name, HealthCheckResponse_ServingStatus_value)
+}
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ grpc.ClientConn
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+const _ = grpc.SupportPackageIsVersion4
+
+// Client API for Health service
+
+type HealthClient interface {
+	Check(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (*HealthCheckResponse, error)
+}
+
+type healthClient struct {
+	cc *grpc.ClientConn
+}
+
+func NewHealthClient(cc *grpc.ClientConn) HealthClient {
+	return &healthClient{cc}
+}
+
+func (c *healthClient) Check(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (*HealthCheckResponse, error) {
+	out := new(HealthCheckResponse)
+	err := grpc.Invoke(ctx, "/grpc.health.v1.Health/Check", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Server API for Health service
+
+type HealthServer interface {
+	Check(context.Context, *HealthCheckRequest) (*HealthCheckResponse, error)
+}
+
+func RegisterHealthServer(s *grpc.Server, srv HealthServer) {
+	s.RegisterService(&_Health_serviceDesc, srv)
+}
+
+func _Health_Check_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(HealthCheckRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(HealthServer).Check(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/grpc.health.v1.Health/Check",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(HealthServer).Check(ctx, req.(*HealthCheckRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+var _Health_serviceDesc = grpc.ServiceDesc{
+	ServiceName: "grpc.health.v1.Health",
+	HandlerType: (*HealthServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "Check",
+			Handler:    _Health_Check_Handler,
+		},
+	},
+	Streams:  []grpc.StreamDesc{},
+	Metadata: "health.proto",
+}
+
+func init() { proto.RegisterFile("health.proto", fileDescriptor0) }
+
+var fileDescriptor0 = []byte{
+	// 204 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0xe2, 0xe2, 0xc9, 0x48, 0x4d, 0xcc,
+	0x29, 0xc9, 0xd0, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0xe2, 0x4b, 0x2f, 0x2a, 0x48, 0xd6, 0x83,
+	0x0a, 0x95, 0x19, 0x2a, 0xe9, 0x71, 0x09, 0x79, 0x80, 0x39, 0xce, 0x19, 0xa9, 0xc9, 0xd9, 0x41,
+	0xa9, 0x85, 0xa5, 0xa9, 0xc5, 0x25, 0x42, 0x12, 0x5c, 0xec, 0xc5, 0xa9, 0x45, 0x65, 0x99, 0xc9,
+	0xa9, 0x12, 0x8c, 0x0a, 0x8c, 0x1a, 0x9c, 0x41, 0x30, 0xae, 0xd2, 0x1c, 0x46, 0x2e, 0x61, 0x14,
+	0x0d, 0xc5, 0x05, 0xf9, 0x79, 0xc5, 0xa9, 0x42, 0x9e, 0x5c, 0x6c, 0xc5, 0x25, 0x89, 0x25, 0xa5,
+	0xc5, 0x60, 0x0d, 0x7c, 0x46, 0x86, 0x7a, 0xa8, 0x16, 0xe9, 0x61, 0xd1, 0xa4, 0x17, 0x0c, 0x32,
+	0x34, 0x2f, 0x3d, 0x18, 0xac, 0x31, 0x08, 0x6a, 0x80, 0x92, 0x15, 0x17, 0x2f, 0x8a, 0x84, 0x10,
+	0x37, 0x17, 0x7b, 0xa8, 0x9f, 0xb7, 0x9f, 0x7f, 0xb8, 0x9f, 0x00, 0x03, 0x88, 0x13, 0xec, 0x1a,
+	0x14, 0xe6, 0xe9, 0xe7, 0x2e, 0xc0, 0x28, 0xc4, 0xcf, 0xc5, 0xed, 0xe7, 0x1f, 0x12, 0x0f, 0x13,
+	0x60, 0x32, 0x8a, 0xe2, 0x62, 0x83, 0x58, 0x24, 0x14, 0xc0, 0xc5, 0x0a, 0xb6, 0x4c, 0x48, 0x09,
+	0xaf, 0x4b, 0xc0, 0xfe, 0x95, 0x52, 0x26, 0xc2, 0xb5, 0x49, 0x6c, 0xe0, 0x10, 0x34, 0x06, 0x04,
+	0x00, 0x00, 0xff, 0xff, 0xac, 0x56, 0x2a, 0xcb, 0x51, 0x01, 0x00, 0x00,
+}

vendor/google.golang.org/grpc/health/grpc_health_v1/health.proto

@@ -0,0 +1,20 @@
+syntax = "proto3";
+
+package grpc.health.v1;
+
+message HealthCheckRequest {
+  string service = 1;
+}
+
+message HealthCheckResponse {
+  enum ServingStatus {
+ 	UNKNOWN = 0;
+	SERVING = 1;
+	NOT_SERVING = 2;
+  }
+  ServingStatus status = 1;
+}
+
+service Health{
+  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);
+} 

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

@@ -0,0 +1,52 @@
+// Package health provides some utility functions to health-check a server. The implementation
+// is based on protobuf. Users need to write their own implementations if other IDLs are used.
+package health
+
+import (
+	"sync"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	healthpb "google.golang.org/grpc/health/grpc_health_v1"
+)
+
+// Server implements `service Health`.
+type Server struct {
+	mu sync.Mutex
+	// statusMap stores the serving status of the services this Server monitors.
+	statusMap map[string]healthpb.HealthCheckResponse_ServingStatus
+}
+
+// NewServer returns a new Server.
+func NewServer() *Server {
+	return &Server{
+		statusMap: make(map[string]healthpb.HealthCheckResponse_ServingStatus),
+	}
+}
+
+// Check implements `service Health`.
+func (s *Server) Check(ctx context.Context, in *healthpb.HealthCheckRequest) (*healthpb.HealthCheckResponse, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if in.Service == "" {
+		// check the server overall health status.
+		return &healthpb.HealthCheckResponse{
+			Status: healthpb.HealthCheckResponse_SERVING,
+		}, nil
+	}
+	if status, ok := s.statusMap[in.Service]; ok {
+		return &healthpb.HealthCheckResponse{
+			Status: status,
+		}, nil
+	}
+	return nil, grpc.Errorf(codes.NotFound, "unknown service")
+}
+
+// SetServingStatus is called when need to reset the serving status of a service
+// or insert a new service entry into the statusMap.
+func (s *Server) SetServingStatus(service string, status healthpb.HealthCheckResponse_ServingStatus) {
+	s.mu.Lock()
+	s.statusMap[service] = status
+	s.mu.Unlock()
+}