cli: reload Oracle service on USR1

Which allows to enable/disable the service, change nodes, keys and other
settings. Unfortunately, atomic.Value doesn't allow Store(nil), so we have to
store a pointer there that can point to nil interface.

cli/server/server.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/nspcc-dev/neo-go/cli/options"
 	"github.com/nspcc-dev/neo-go/pkg/config"
+	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/consensus"
 	"github.com/nspcc-dev/neo-go/pkg/core"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
@@ -385,14 +386,14 @@ func restoreDB(ctx *cli.Context) error {
 	return nil
 }
 
-func mkOracle(config network.ServerConfig, chain *core.Blockchain, serv *network.Server, log *zap.Logger) (*oracle.Oracle, error) {
-	if !config.OracleCfg.Enabled {
+func mkOracle(config config.OracleConfiguration, magic netmode.Magic, chain *core.Blockchain, serv *network.Server, log *zap.Logger) (*oracle.Oracle, error) {
+	if !config.Enabled {
 		return nil, nil
 	}
 	orcCfg := oracle.Config{
 		Log:           log,
-		Network:       config.Net,
-		MainCfg:       config.OracleCfg,
+		Network:       magic,
+		MainCfg:       config,
 		Chain:         chain,
 		OnTransaction: serv.RelayTxn,
 	}
@@ -492,7 +493,7 @@ func startServer(ctx *cli.Context) error {
 	}
 	serv.AddExtensibleService(sr, stateroot.Category, sr.OnPayload)
 
-	oracleSrv, err := mkOracle(serverConfig, chain, serv, log)
+	oracleSrv, err := mkOracle(cfg.ApplicationConfiguration.Oracle, cfg.ProtocolConfiguration.Magic, chain, serv, log)
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
@@ -513,8 +514,9 @@ func startServer(ctx *cli.Context) error {
 		rpcServer.Start()
 	}
 
-	sighupCh := make(chan os.Signal, 1)
-	signal.Notify(sighupCh, syscall.SIGHUP)
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGHUP)
+	signal.Notify(sigCh, syscall.SIGUSR1)
 
 	fmt.Fprintln(ctx.App.Writer, Logo())
 	fmt.Fprintln(ctx.App.Writer, serv.UserAgent)
@@ -527,7 +529,7 @@ Main:
 		case err := <-errChan:
 			shutdownErr = fmt.Errorf("server error: %w", err)
 			cancel()
-		case sig := <-sighupCh:
+		case sig := <-sigCh:
 			log.Info("signal received", zap.Stringer("name", sig))
 			cfgnew, err := getConfigFromContext(ctx)
 			if err != nil {
@@ -557,10 +559,27 @@ Main:
 				prometheus.ShutDown()
 				prometheus = metrics.NewPrometheusService(cfgnew.ApplicationConfiguration.Prometheus, log)
 				go prometheus.Start()
+			case syscall.SIGUSR1:
+				if oracleSrv != nil {
+					chain.SetOracle(nil)
+					rpcServer.SetOracleHandler(nil)
+					oracleSrv.Shutdown()
+				}
+				oracleSrv, err = mkOracle(cfgnew.ApplicationConfiguration.Oracle, cfgnew.ProtocolConfiguration.Magic, chain, serv, log)
+				if err != nil {
+					log.Error("failed to create oracle service", zap.Error(err))
+					break // Keep going.
+				}
+				if oracleSrv != nil {
+					rpcServer.SetOracleHandler(oracleSrv)
+					if serv.IsInSync() {
+						oracleSrv.Start()
+					}
+				}
 			}
 			cfg = cfgnew
 		case <-grace.Done():
-			signal.Stop(sighupCh)
+			signal.Stop(sigCh)
 			serv.Shutdown()
 			break Main
 		}

pkg/core/blockchain.go

@@ -303,14 +303,28 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.L
 // must be called before `bc.Run()` to avoid data race.
 func (bc *Blockchain) SetOracle(mod native.OracleService) {
 	orc := bc.contracts.Oracle
+	if mod != nil {
 		md, ok := orc.GetMethod(manifest.MethodVerify, -1)
 		if !ok {
 			panic(fmt.Errorf("%s method not found", manifest.MethodVerify))
 		}
 		mod.UpdateNativeContract(orc.NEF.Script, orc.GetOracleResponseScript(),
 			orc.Hash, md.MD.Offset)
-	orc.Module.Store(mod)
-	bc.contracts.Designate.OracleService.Store(mod)
+		keys, _, err := bc.contracts.Designate.GetDesignatedByRole(bc.dao, noderoles.Oracle, bc.BlockHeight())
+		if err != nil {
+			bc.log.Error("failed to get oracle key list")
+			return
+		}
+		mod.UpdateOracleNodes(keys)
+		reqs, err := bc.contracts.Oracle.GetRequests(bc.dao)
+		if err != nil {
+			bc.log.Error("failed to get current oracle request list")
+			return
+		}
+		mod.AddRequests(reqs)
+	}
+	orc.Module.Store(&mod)
+	bc.contracts.Designate.OracleService.Store(&mod)
 }
 
 // SetNotary sets notary module. It doesn't protected by mutex and

pkg/core/native/designate.go

@@ -238,8 +238,8 @@ func (s *Designate) updateCachedRoleData(cache *DesignationCache, d *dao.Simple,
 func (s *Designate) notifyRoleChanged(v *roleData, r noderoles.Role) {
 	switch r {
 	case noderoles.Oracle:
-		if orc, _ := s.OracleService.Load().(OracleService); orc != nil {
-			orc.UpdateOracleNodes(v.nodes.Copy())
+		if orc, _ := s.OracleService.Load().(*OracleService); orc != nil && *orc != nil {
+			(*orc).UpdateOracleNodes(v.nodes.Copy())
 		}
 	case noderoles.P2PNotary:
 		if ntr, _ := s.NotaryService.Load().(NotaryService); ntr != nil {

pkg/core/native/oracle.go

@@ -113,7 +113,10 @@ func copyOracleCache(src, dst *OracleCache) {
 }
 
 func newOracle() *Oracle {
-	o := &Oracle{ContractMD: *interop.NewContractMD(nativenames.Oracle, oracleContractID)}
+	o := &Oracle{
+		ContractMD:  *interop.NewContractMD(nativenames.Oracle, oracleContractID),
+		newRequests: make(map[uint64]*state.OracleRequest),
+	}
 	defer o.UpdateHash()
 
 	o.oracleScript = CreateOracleResponseScript(o.Hash)
@@ -161,11 +164,7 @@ func (o *Oracle) GetOracleResponseScript() []byte {
 
 // OnPersist implements the Contract interface.
 func (o *Oracle) OnPersist(ic *interop.Context) error {
-	var err error
-	if o.newRequests == nil {
-		o.newRequests, err = o.getRequests(ic.DAO)
-	}
-	return err
+	return nil
 }
 
 // PostPersist represents `postPersist` method.
@@ -177,7 +176,7 @@ func (o *Oracle) PostPersist(ic *interop.Context) error {
 	single := big.NewInt(p)
 	var removedIDs []uint64
 
-	orc, _ := o.Module.Load().(OracleService)
+	orc, _ := o.Module.Load().(*OracleService)
 	for _, tx := range ic.Block.Transactions {
 		resp := getResponse(tx)
 		if resp == nil {
@@ -189,7 +188,7 @@ func (o *Oracle) PostPersist(ic *interop.Context) error {
 			continue
 		}
 		ic.DAO.DeleteStorageItem(o.ID, reqKey)
-		if orc != nil {
+		if orc != nil && *orc != nil {
 			removedIDs = append(removedIDs, resp.ID)
 		}
 
@@ -229,8 +228,8 @@ func (o *Oracle) PostPersist(ic *interop.Context) error {
 		o.GAS.mint(ic, nodes[i].GetScriptHash(), &reward[i], false)
 	}
 
-	if len(removedIDs) != 0 && orc != nil {
-		orc.RemoveRequests(removedIDs)
+	if len(removedIDs) != 0 {
+		(*orc).RemoveRequests(removedIDs)
 	}
 	return o.updateCache(ic.DAO)
 }
@@ -415,7 +414,10 @@ func (o *Oracle) PutRequestInternal(id uint64, req *state.OracleRequest, d *dao.
 	if err := putConvertibleToDAO(o.ID, d, reqKey, req); err != nil {
 		return err
 	}
+	orc, _ := o.Module.Load().(*OracleService)
+	if orc != nil && *orc != nil {
 		o.newRequests[id] = req
+	}
 
 	// Add request ID to the id list.
 	lst := new(IDList)
@@ -493,8 +495,8 @@ func (o *Oracle) getOriginalTxID(d *dao.Simple, tx *transaction.Transaction) uti
 	return tx.Hash()
 }
 
-// getRequests returns all requests which have not been finished yet.
-func (o *Oracle) getRequests(d *dao.Simple) (map[uint64]*state.OracleRequest, error) {
+// GetRequests returns all requests which have not been finished yet.
+func (o *Oracle) GetRequests(d *dao.Simple) (map[uint64]*state.OracleRequest, error) {
 	var reqs = make(map[uint64]*state.OracleRequest)
 	var err error
 	d.Seek(o.ID, storage.SeekRange{Prefix: prefixRequest}, func(k, v []byte) bool {
@@ -534,8 +536,8 @@ func (o *Oracle) getConvertibleFromDAO(d *dao.Simple, key []byte, item stackitem
 
 // updateCache updates cached Oracle values if they've been changed.
 func (o *Oracle) updateCache(d *dao.Simple) error {
-	orc, _ := o.Module.Load().(OracleService)
-	if orc == nil {
+	orc, _ := o.Module.Load().(*OracleService)
+	if orc == nil || *orc == nil {
 		return nil
 	}
 
@@ -547,7 +549,7 @@ func (o *Oracle) updateCache(d *dao.Simple) error {
 			delete(reqs, id)
 		}
 	}
-	orc.AddRequests(reqs)
+	(*orc).AddRequests(reqs)
 	return nil
 }
 

pkg/services/oracle/oracle.go

@@ -186,6 +186,7 @@ func (o *Oracle) Shutdown() {
 	if !o.running {
 		return
 	}
+	o.Log.Info("stopping oracle service")
 	o.running = false
 	close(o.close)
 	o.ResponseHandler.Shutdown()

pkg/services/oracle/oracle_test.go

@@ -121,8 +121,8 @@ func TestCreateResponseTx(t *testing.T) {
 		Result: []byte{0},
 	}
 	cInvoker.Invoke(t, stackitem.Null{}, "requestURL", req.URL, *req.Filter, req.CallbackMethod, req.UserData, int64(req.GasForResponse))
-	orc.UpdateOracleNodes(keys.PublicKeys{acc.PrivateKey().PublicKey()})
 	bc.SetOracle(orc)
+	orc.UpdateOracleNodes(keys.PublicKeys{acc.PrivateKey().PublicKey()})
 	tx, err = orc.CreateResponseTx(int64(req.GasForResponse), 1, resp)
 	require.NoError(t, err)
 	assert.Equal(t, 166, tx.Size())

pkg/services/rpcsrv/server.go

@@ -122,7 +122,7 @@ type (
 		network          netmode.Magic
 		stateRootEnabled bool
 		coreServer       *network.Server
-		oracle           OracleHandler
+		oracle           *atomic.Value
 		log              *zap.Logger
 		https            *http.Server
 		shutdown         chan struct{}
@@ -275,6 +275,10 @@ func New(chain Ledger, conf config.RPC, coreServer *network.Server,
 			log.Info("SessionPoolSize is not set or wrong, setting default value", zap.Int("SessionPoolSize", defaultSessionPoolSize))
 		}
 	}
+	var oracleWrapped = new(atomic.Value)
+	if orc != nil {
+		oracleWrapped.Store(&orc)
+	}
 	return Server{
 		Server:           httpServer,
 		chain:            chain,
@@ -284,7 +288,7 @@ func New(chain Ledger, conf config.RPC, coreServer *network.Server,
 		stateRootEnabled: protoCfg.StateRootInHeader,
 		coreServer:       coreServer,
 		log:              log,
-		oracle:           orc,
+		oracle:           oracleWrapped,
 		https:            tlsServer,
 		shutdown:         make(chan struct{}),
 		started:          atomic.NewBool(false),
@@ -400,6 +404,11 @@ func (s *Server) Shutdown() {
 	<-s.executionCh
 }
 
+// SetOracleHandler allows to update oracle handler used by the Server.
+func (s *Server) SetOracleHandler(orc OracleHandler) {
+	s.oracle.Store(&orc)
+}
+
 func (s *Server) handleHTTPRequest(w http.ResponseWriter, httpRequest *http.Request) {
 	req := params.NewRequest()
 
@@ -2328,7 +2337,8 @@ func getRelayResult(err error, hash util.Uint256) (interface{}, *neorpc.Error) {
 }
 
 func (s *Server) submitOracleResponse(ps params.Params) (interface{}, *neorpc.Error) {
-	if s.oracle == nil {
+	oracle := s.oracle.Load().(*OracleHandler)
+	if oracle == nil || *oracle == nil {
 		return nil, neorpc.NewRPCError("Oracle is not enabled", "")
 	}
 	var pub *keys.PublicKey
@@ -2355,7 +2365,7 @@ func (s *Server) submitOracleResponse(ps params.Params) (interface{}, *neorpc.Er
 	if !pub.Verify(msgSig, hash.Sha256(data).BytesBE()) {
 		return nil, neorpc.NewRPCError("Invalid request signature", "")
 	}
-	s.oracle.AddResponse(pub, uint64(reqID), txSig)
+	(*oracle).AddResponse(pub, uint64(reqID), txSig)
 	return json.RawMessage([]byte("{}")), nil
 }