Add handling of AuthStatusRequest.

Signed-off-by: Siyuan Zhang <sizhang@google.com>

etcdserver/apply.go

@@ -64,6 +64,7 @@ type applierV3 interface {
 
 	AuthEnable() (*pb.AuthEnableResponse, error)
 	AuthDisable() (*pb.AuthDisableResponse, error)
+	AuthStatus() (*pb.AuthStatusResponse, error)
 
 	UserAdd(ua *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error)
 	UserDelete(ua *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error)
@@ -143,6 +144,8 @@ func (a *applierV3backend) Apply(r *pb.InternalRaftRequest) *applyResult {
 		ar.resp, ar.err = a.s.applyV3.AuthEnable()
 	case r.AuthDisable != nil:
 		ar.resp, ar.err = a.s.applyV3.AuthDisable()
+	case r.AuthStatus != nil:
+		ar.resp, ar.err = a.s.applyV3.AuthStatus()
 	case r.AuthUserAdd != nil:
 		ar.resp, ar.err = a.s.applyV3.UserAdd(r.AuthUserAdd)
 	case r.AuthUserDelete != nil:
@@ -719,6 +722,12 @@ func (a *applierV3backend) AuthDisable() (*pb.AuthDisableResponse, error) {
 	return &pb.AuthDisableResponse{Header: newHeader(a.s)}, nil
 }
 
+func (a *applierV3backend) AuthStatus() (*pb.AuthStatusResponse, error) {
+	enabled := a.s.AuthStore().IsAuthEnabled()
+	authRevision := a.s.AuthStore().Revision()
+	return &pb.AuthStatusResponse{Header: newHeader(a.s), Enabled: enabled, AuthRevision: authRevision}, nil
+}
+
 func (a *applierV3backend) Authenticate(r *pb.InternalAuthenticateRequest) (*pb.AuthenticateResponse, error) {
 	ctx := context.WithValue(context.WithValue(a.s.ctx, auth.AuthenticateParamIndex{}, a.s.consistIndex.ConsistentIndex()), auth.AuthenticateParamSimpleTokenPrefix{}, r.SimpleToken)
 	resp, err := a.s.AuthStore().Authenticate(ctx, r.Name, r.Password)