decouple rpc server and shutdown logic from cmd.

node/rpc.go

@@ -0,0 +1,143 @@
+package node
+
+import (
+	"context"
+	"encoding/json"
+	"net"
+	"net/http"
+	_ "net/http/pprof"
+	"runtime"
+	"strconv"
+
+	"github.com/ipfs/go-cid"
+	logging "github.com/ipfs/go-log/v2"
+	"github.com/multiformats/go-multiaddr"
+	manet "github.com/multiformats/go-multiaddr/net"
+	"go.opencensus.io/tag"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/go-jsonrpc"
+	"github.com/filecoin-project/go-jsonrpc/auth"
+
+	"github.com/filecoin-project/lotus/api"
+	"github.com/filecoin-project/lotus/api/v0api"
+	"github.com/filecoin-project/lotus/api/v1api"
+	"github.com/filecoin-project/lotus/metrics"
+	"github.com/filecoin-project/lotus/node/impl"
+)
+
+var rpclog = logging.Logger("rpc")
+
+func ServeRPC(a v1api.FullNode, addr multiaddr.Multiaddr, maxRequestSize int64) (StopFunc, error) {
+	serverOptions := make([]jsonrpc.ServerOption, 0)
+	if maxRequestSize != 0 { // config set
+		serverOptions = append(serverOptions, jsonrpc.WithMaxRequestSize(maxRequestSize))
+	}
+	serveRpc := func(path string, hnd interface{}) {
+		rpcServer := jsonrpc.NewServer(serverOptions...)
+		rpcServer.Register("Filecoin", hnd)
+
+		ah := &auth.Handler{
+			Verify: a.AuthVerify,
+			Next:   rpcServer.ServeHTTP,
+		}
+
+		http.Handle(path, ah)
+	}
+
+	pma := api.PermissionedFullAPI(metrics.MetricedFullAPI(a))
+
+	serveRpc("/rpc/v1", pma)
+	serveRpc("/rpc/v0", &v0api.WrapperV1Full{FullNode: pma})
+
+	importAH := &auth.Handler{
+		Verify: a.AuthVerify,
+		Next:   handleImport(a.(*impl.FullNodeAPI)),
+	}
+
+	http.Handle("/rest/v0/import", importAH)
+
+	http.Handle("/debug/metrics", metrics.Exporter())
+	http.Handle("/debug/pprof-set/block", handleFractionOpt("BlockProfileRate", runtime.SetBlockProfileRate))
+	http.Handle("/debug/pprof-set/mutex", handleFractionOpt("MutexProfileFraction", func(x int) {
+		runtime.SetMutexProfileFraction(x)
+	}))
+
+	// Start listening to the addr; if invalid or occupied, we will fail early.
+	lst, err := manet.Listen(addr)
+	if err != nil {
+		return nil, xerrors.Errorf("could not listen: %w", err)
+	}
+
+	// Instantiate the server and start listening.
+	srv := &http.Server{
+		Handler: http.DefaultServeMux,
+		BaseContext: func(listener net.Listener) context.Context {
+			ctx, _ := tag.New(context.Background(), tag.Upsert(metrics.APIInterface, "lotus-daemon"))
+			return ctx
+		},
+	}
+
+	go func() {
+		err = srv.Serve(manet.NetListener(lst))
+		if err != http.ErrServerClosed {
+			log.Warnf("rpc server failed: %s", err)
+		}
+	}()
+
+	return srv.Shutdown, err
+}
+
+func handleImport(a *impl.FullNodeAPI) func(w http.ResponseWriter, r *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "PUT" {
+			w.WriteHeader(404)
+			return
+		}
+		if !auth.HasPerm(r.Context(), nil, api.PermWrite) {
+			w.WriteHeader(401)
+			_ = json.NewEncoder(w).Encode(struct{ Error string }{"unauthorized: missing write permission"})
+			return
+		}
+
+		c, err := a.ClientImportLocal(r.Context(), r.Body)
+		if err != nil {
+			w.WriteHeader(500)
+			_ = json.NewEncoder(w).Encode(struct{ Error string }{err.Error()})
+			return
+		}
+		w.WriteHeader(200)
+		err = json.NewEncoder(w).Encode(struct{ Cid cid.Cid }{c})
+		if err != nil {
+			log.Errorf("/rest/v0/import: Writing response failed: %+v", err)
+			return
+		}
+	}
+}
+
+func handleFractionOpt(name string, setter func(int)) http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(rw, "only POST allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		if err := r.ParseForm(); err != nil {
+			http.Error(rw, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		asfr := r.Form.Get("x")
+		if len(asfr) == 0 {
+			http.Error(rw, "parameter 'x' must be set", http.StatusBadRequest)
+			return
+		}
+
+		fr, err := strconv.Atoi(asfr)
+		if err != nil {
+			http.Error(rw, err.Error(), http.StatusBadRequest)
+			return
+		}
+		log.Infof("setting %s to %d", name, fr)
+		setter(fr)
+	}
+}

node/shutdown.go

@@ -0,0 +1,56 @@
+package node
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+type ShutdownHandler struct {
+	Component string
+	StopFunc  StopFunc
+}
+
+// MonitorShutdown manages shutdown requests, by watching signals and invoking
+// the supplied handlers in order.
+//
+// It watches SIGTERM and SIGINT OS signals, as well as the trigger channel.
+// When any of them fire, it calls the supplied handlers in order. If any of
+// them errors, it merely logs the error.
+//
+// Once the shutdown has completed, it closes the returned channel. The caller
+// can watch this channel
+func MonitorShutdown(triggerCh <-chan struct{}, handlers ...ShutdownHandler) <-chan struct{} {
+	sigCh := make(chan os.Signal, 2)
+	out := make(chan struct{})
+
+	go func() {
+		select {
+		case sig := <-sigCh:
+			log.Warnw("received shutdown", "signal", sig)
+		case <-triggerCh:
+			log.Warn("received shutdown")
+		}
+
+		log.Warn("Shutting down...")
+
+		// Call all the handlers, logging on failure and success.
+		for _, h := range handlers {
+			if err := h.StopFunc(context.TODO()); err != nil {
+				log.Errorf("shutting down %s failed: %s", h.Component, err)
+				continue
+			}
+			log.Infof("%s shut down successfully ", h.Component)
+		}
+
+		log.Warn("Graceful shutdown successful")
+
+		// Sync all loggers.
+		_ = log.Sync() //nolint:errcheck
+		close(out)
+	}()
+
+	signal.Notify(sigCh, syscall.SIGTERM, syscall.SIGINT)
+	return out
+}

node/shutdown_test.go

@@ -0,0 +1,36 @@
+package node
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMonitorShutdown(t *testing.T) {
+	signalCh := make(chan struct{})
+
+	// Three shutdown handlers.
+	var wg sync.WaitGroup
+	wg.Add(3)
+	h := ShutdownHandler{
+		Component: "handler",
+		StopFunc: func(_ context.Context) error {
+			wg.Done()
+			return nil
+		},
+	}
+
+	finishCh := MonitorShutdown(signalCh, h, h, h)
+
+	// Nothing here after 10ms.
+	time.Sleep(10 * time.Millisecond)
+	require.Len(t, finishCh, 0)
+
+	// Now trigger the shutdown.
+	close(signalCh)
+	wg.Wait()
+	<-finishCh
+}