handle clean shutdown

cln_plugin/cln_plugin.go

@@ -66,6 +66,10 @@ func (c *ClnPlugin) Start() {
 	c.setupLogging()
 	go c.listenRequests()
 	<-c.done
+	s := c.server
+	if s != nil {
+		<-s.completed
+	}
 }
 
 // Stops the cln plugin. Drops any remaining work immediately.

cln_plugin/cmd/main.go

@@ -2,11 +2,20 @@ package main
 
 import (
 	"os"
+	"os/signal"
+	"syscall"
 
 	"github.com/breez/lspd/cln_plugin"
 )
 
 func main() {
 	plugin := cln_plugin.NewClnPlugin(os.Stdin, os.Stdout)
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		<-c
+		// Stop everything gracefully on stop signal
+		plugin.Stop()
+	}()
 	plugin.Start()
 }

cln_plugin/server.go

@@ -35,6 +35,7 @@ type server struct {
 	newSubscriber     chan struct{}
 	started           chan struct{}
 	done              chan struct{}
+	completed         chan struct{}
 	startError        chan error
 	sendQueue         chan *htlcAcceptedMsg
 	recvQueue         chan *htlcResultMsg
@@ -76,6 +77,7 @@ func (s *server) Start() error {
 	}
 
 	s.done = make(chan struct{})
+	s.completed = make(chan struct{})
 	s.newSubscriber = make(chan struct{})
 	s.grpcServer = grpc.NewServer(
 		grpc.KeepaliveParams(keepalive.ServerParameters{
@@ -93,7 +95,9 @@ func (s *server) Start() error {
 	go s.listenHtlcRequests()
 	go s.listenHtlcResponses()
 	close(s.started)
-	return s.grpcServer.Serve(lis)
+	err = s.grpcServer.Serve(lis)
+	close(s.completed)
+	return err
 }
 
 // Waits until the server has started, or errored during startup.
@@ -119,6 +123,7 @@ func (s *server) Stop() {
 	s.grpcServer = nil
 
 	close(s.done)
+	<-s.completed
 	log.Printf("Server stopped.")
 }
 

go.mod

@@ -4,7 +4,7 @@ go 1.19
 
 require (
 	github.com/aws/aws-sdk-go v1.30.20
-	github.com/breez/lntest v0.0.17
+	github.com/breez/lntest v0.0.18
 	github.com/btcsuite/btcd v0.23.3
 	github.com/btcsuite/btcd/btcec/v2 v2.2.1
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1

itest/cln_lspd_node.go

@@ -8,6 +8,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"sync"
+	"syscall"
 
 	"github.com/breez/lntest"
 	lspd "github.com/breez/lspd/rpc"
@@ -109,6 +110,7 @@ func (c *ClnLspNode) Start() {
 	})
 
 	cmd := exec.CommandContext(c.harness.Ctx, c.lspBase.scriptFilePath)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
 	logFile, err := os.Create(c.logFilePath)
 	if err != nil {
 		lntest.PerformCleanup(cleanups)
@@ -136,7 +138,7 @@ func (c *ClnLspNode) Start() {
 				return nil
 			}
 
-			proc.Kill()
+			syscall.Kill(-proc.Pid, syscall.SIGINT)
 
 			log.Printf("About to wait for lspd to exit")
 			status, err := proc.Wait()

itest/lnd_lspd_node.go

@@ -10,6 +10,7 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"syscall"
 
 	"github.com/breez/lntest"
 	lspd "github.com/breez/lspd/rpc"
@@ -132,6 +133,7 @@ func (c *LndLspNode) Start() {
 	}
 
 	cmd := exec.CommandContext(c.harness.Ctx, c.lspBase.scriptFilePath)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
 	logFile, err := os.Create(c.logFilePath)
 	if err != nil {
 		lntest.PerformCleanup(cleanups)
@@ -159,7 +161,7 @@ func (c *LndLspNode) Start() {
 				return nil
 			}
 
-			proc.Kill()
+			syscall.Kill(-proc.Pid, syscall.SIGINT)
 
 			log.Printf("About to wait for lspd to exit")
 			status, err := proc.Wait()