first take at "daemon stop" command

Fixes #1827

TODO: plumb the daemon-stopping into lotus-storage-miner, too

api/api_common.go

@@ -34,6 +34,9 @@ type Common interface {
 
 	LogList(context.Context) ([]string, error)
 	LogSetLevel(context.Context, string, string) error
+
+	// trigger graceful shutdown
+	Shutdown(context.Context) error
 }
 
 // Version provides various build-time information

api/apistruct/struct.go

@@ -47,6 +47,8 @@ type CommonStruct struct {
 
 		LogList     func(context.Context) ([]string, error)     `perm:"write"`
 		LogSetLevel func(context.Context, string, string) error `perm:"write"`
+
+		Shutdown func(context.Context) error `perm:"admin"`
 	}
 }
 
@@ -293,6 +295,10 @@ func (c *CommonStruct) LogSetLevel(ctx context.Context, group, level string) err
 	return c.Internal.LogSetLevel(ctx, group, level)
 }
 
+func (c *CommonStruct) Shutdown(ctx context.Context) error {
+	return c.Internal.Shutdown(ctx)
+}
+
 // FullNodeStruct
 
 func (c *FullNodeStruct) ClientListImports(ctx context.Context) ([]api.Import, error) {

cmd/lotus/daemon.go

@@ -29,6 +29,7 @@ import (
 	"github.com/filecoin-project/lotus/chain/stmgr"
 	"github.com/filecoin-project/lotus/chain/store"
 	"github.com/filecoin-project/lotus/chain/vm"
+	lcli "github.com/filecoin-project/lotus/cli"
 	"github.com/filecoin-project/lotus/lib/peermgr"
 	"github.com/filecoin-project/lotus/metrics"
 	"github.com/filecoin-project/lotus/node"
@@ -49,7 +50,18 @@ var daemonStopCmd = &cli.Command{
 	Usage: "Stop a running lotus daemon",
 	Flags: []cli.Flag{},
 	Action: func(cctx *cli.Context) error {
-		panic("wombat attack")
+		api, closer, err := lcli.GetAPI(cctx)
+		if err != nil {
+			return err
+		}
+		defer closer()
+
+		err = api.Shutdown(lcli.ReqContext(cctx))
+		if err != nil {
+			return err
+		}
+
+		return nil
 	},
 }
 
@@ -179,12 +191,15 @@ var DaemonCmd = &cli.Command{
 			genesis = node.Override(new(modules.Genesis), testing.MakeGenesis(cctx.String(makeGenFlag), cctx.String(preTemplateFlag)))
 		}
 
+		shutdownCh := make(chan struct{})
+
 		var api api.FullNode
 
 		stop, err := node.New(ctx,
 			node.FullAPI(&api),
 
 			node.Override(new(dtypes.Bootstrapper), isBootstrapper),
+			node.Override(new(dtypes.ShutdownCh), shutdownCh),
 			node.Online(),
 			node.Repo(r),
 
@@ -230,7 +245,7 @@ var DaemonCmd = &cli.Command{
 		}
 
 		// TODO: properly parse api endpoint (or make it a URL)
-		return serveRPC(api, stop, endpoint)
+		return serveRPC(api, stop, endpoint, shutdownCh)
 	},
 	Subcommands: []*cli.Command{
 		daemonStopCmd,

cmd/lotus/rpc.go

@@ -28,7 +28,7 @@ import (
 
 var log = logging.Logger("main")
 
-func serveRPC(a api.FullNode, stop node.StopFunc, addr multiaddr.Multiaddr) error {
+func serveRPC(a api.FullNode, stop node.StopFunc, addr multiaddr.Multiaddr, shutdownCh <-chan struct{}) error {
 	rpcServer := jsonrpc.NewServer()
 	rpcServer.Register("Filecoin", apistruct.PermissionedFullAPI(a))
 
@@ -62,17 +62,23 @@ func serveRPC(a api.FullNode, stop node.StopFunc, addr multiaddr.Multiaddr) erro
 
 	srv := &http.Server{Handler: http.DefaultServeMux}
 
-	sigChan := make(chan os.Signal, 2)
+	sigCh := make(chan os.Signal, 2)
 	go func() {
-		<-sigChan
+		select {
+		case <-sigCh:
+		case <-shutdownCh:
+		}
+
+		log.Warn("Shutting down...")
 		if err := srv.Shutdown(context.TODO()); err != nil {
 			log.Errorf("shutting down RPC server failed: %s", err)
 		}
 		if err := stop(context.TODO()); err != nil {
 			log.Errorf("graceful shutting down failed: %s", err)
 		}
+		log.Warn("Graceful shutdown successful")
 	}()
-	signal.Notify(sigChan, syscall.SIGTERM, syscall.SIGINT)
+	signal.Notify(sigCh, syscall.SIGTERM, syscall.SIGINT)
 
 	return srv.Serve(manet.NetListener(lst))
 }

node/builder.go

@@ -150,6 +150,7 @@ func defaults() []Option {
 		Override(new(helpers.MetricsCtx), context.Background),
 		Override(new(record.Validator), modules.RecordValidator),
 		Override(new(dtypes.Bootstrapper), dtypes.Bootstrapper(false)),
+		Override(new(dtypes.ShutdownCh), make(chan struct{})),
 
 		// Filecoin modules
 

node/impl/common/common.go

@@ -25,9 +25,10 @@ import (
 type CommonAPI struct {
 	fx.In
 
-	APISecret *dtypes.APIAlg
-	Host      host.Host
-	Router    lp2p.BaseIpfsRouting
+	APISecret  *dtypes.APIAlg
+	Host       host.Host
+	Router     lp2p.BaseIpfsRouting
+	ShutdownCh dtypes.ShutdownCh
 }
 
 type jwtPayload struct {
@@ -115,4 +116,9 @@ func (a *CommonAPI) LogSetLevel(ctx context.Context, subsystem, level string) er
 	return logging.SetLogLevel(subsystem, level)
 }
 
+func (a *CommonAPI) Shutdown(ctx context.Context) error {
+	a.ShutdownCh <- struct{}{}
+	return nil
+}
+
 var _ api.Common = &CommonAPI{}

node/modules/dtypes/shutdown.go

@@ -0,0 +1,3 @@
+package dtypes
+
+type ShutdownCh chan struct{}