fix bugs with restarts/interrupts

The password reset daemon wasn't being closed on restarts, so an extra
pwr would be sent w/ every restart. Restarts & Interrupts (Ctrl-C)
rarely worked, as there were multiple listeners to the "RESTART"
channel, and I didn't know the message was consumed by whoever got it
first, meaning if the main thread didn't get it first, the app wouldn't
quit. Listeners are now registered, and the restart message is
re-broadcasted until everyone's got it.

Fixes #264

api.go

@@ -359,6 +359,8 @@ func (app *appContext) ModifyConfig(gc *gin.Context) {
 		} else {
 			RESTART <- true
 		}
+		// Safety Sleep (Ensure shutdown tasks get done)
+		time.Sleep(time.Second)
 	}
 	app.loadConfig()
 	// Reinitialize password validator on config change, as opposed to every applicable request like in python.
@@ -527,5 +529,7 @@ func (app *appContext) Restart() error {
 	} else {
 		RESTART <- true
 	}
+	// Safety Sleep (Ensure shutdown tasks get done)
+	time.Sleep(time.Second)
 	return nil
 }

discord.go

@@ -120,7 +120,7 @@ func (d *DiscordDaemon) run() {
 	defer d.deregisterCommands()
 	defer d.bot.Close()
 
-	d.registerCommands()
+	go d.registerCommands()
 
 	<-d.ShutdownChannel
 	d.ShutdownChannel <- "Down"

main.go

@@ -17,6 +17,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/fatih/color"
@@ -43,6 +44,8 @@ var (
 	SWAGGER            *bool
 	QUIT               = false
 	RUNNING            = false
+	// Used to know how many times to re-broadcast restart signal.
+	RESTARTLISTENERCOUNT = 0
 	warning              = color.New(color.FgYellow).SprintfFunc()
 	info                 = color.New(color.FgMagenta).SprintfFunc()
 	hiwhite              = color.New(color.FgHiWhite).SprintfFunc()
@@ -102,7 +105,6 @@ type appContext struct {
 	host             string
 	port             int
 	version          string
-	quit             chan os.Signal
 	URLBase          string
 	updater          *Updater
 	newUpdate        bool // Whether whatever's in update is new.
@@ -152,6 +154,7 @@ func test(app *appContext) {
 }
 
 func start(asDaemon, firstCall bool) {
+	RESTARTLISTENERCOUNT = 0
 	RUNNING = true
 	defer func() { RUNNING = false }()
 
@@ -250,7 +253,7 @@ func start(asDaemon, firstCall bool) {
 				app.err.Fatalf("Couldn't establish socket connection at %s\n", SOCK)
 			}
 			c := make(chan os.Signal, 1)
-			signal.Notify(c, os.Interrupt)
+			signal.Notify(c, os.Interrupt, syscall.SIGTERM)
 			go func() {
 				<-c
 				os.Remove(SOCK)
@@ -578,15 +581,10 @@ func start(asDaemon, firstCall bool) {
 	} else {
 		app.info.Printf("Loaded @ %s", address)
 	}
-	app.quit = make(chan os.Signal)
-	signal.Notify(app.quit, os.Interrupt)
-	go func() {
-		for range app.quit {
-			app.shutdown()
-		}
-	}()
-	for range RESTART {
-		println("got it too!")
+
+	waitForRestart()
+
+	app.info.Printf("Restart/Quit signal received, give me a second!")
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 	defer cancel()
 	if err := SRV.Shutdown(ctx); err != nil {
@@ -594,24 +592,27 @@ func start(asDaemon, firstCall bool) {
 	}
 	app.info.Println("Server shut down.")
 	return
-	}
 }
 
-func (app *appContext) shutdown() {
-	app.info.Println("Shutting down...")
+func shutdown() {
 	QUIT = true
 	RESTART <- true
-	for {
-		if RUNNING {
-			continue
-		}
-		cntx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-		defer cancel()
-		if err := SRV.Shutdown(cntx); err != nil {
-			app.err.Fatalf("Server shutdown error: %s", err)
-		}
+	// Safety Sleep (Ensure shutdown tasks get done)
+	time.Sleep(time.Second)
+}
 
-		os.Exit(1)
+func (app *appContext) shutdown() {
+	app.info.Println("Shutting down...")
+	shutdown()
+}
+
+// Receives a restart signal and re-broadcasts it for other components.
+func waitForRestart() {
+	RESTARTLISTENERCOUNT++
+	<-RESTART
+	RESTARTLISTENERCOUNT--
+	if RESTARTLISTENERCOUNT > 0 {
+		RESTART <- true
 	}
 }
 
@@ -686,6 +687,15 @@ func main() {
 		TEST = true
 	}
 	loadFilesystems()
+
+	quit := make(chan os.Signal, 0)
+	signal.Notify(quit, os.Interrupt, syscall.SIGTERM)
+	// defer close(quit)
+	go func() {
+		<-quit
+		shutdown()
+	}()
+
 	if flagPassed("start") {
 		args := []string{}
 		for i, f := range os.Args {
@@ -760,7 +770,7 @@ You can then run:
 		start(false, true)
 		for {
 			if QUIT {
-				continue
+				break
 			}
 			printVersion()
 			start(false, false)

pwreset.go

@@ -46,7 +46,7 @@ func (app *appContext) StartPWR() {
 		app.err.Printf("Failed to start password reset daemon: %s", err)
 	}
 
-	<-RESTART
+	waitForRestart()
 }
 
 // PasswordReset represents a passwordreset-xyz.json file generated by Jellyfin.

restart.go

@@ -1,4 +1,4 @@
-// +build !windows
+//go:build !windows
 
 package main
 
@@ -11,9 +11,10 @@ import (
 
 func (app *appContext) HardRestart() error {
 	defer func() {
+		quit := make(chan os.Signal, 0)
 		if r := recover(); r != nil {
-			signal.Notify(app.quit, os.Interrupt)
-			<-app.quit
+			signal.Notify(quit, os.Interrupt, syscall.SIGTERM)
+			<-quit
 		}
 	}()
 	args := os.Args

tray.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"os/signal"
 	"syscall"
+	"time"
 
 	"github.com/getlantern/systray"
 )
@@ -26,6 +27,8 @@ func onExit() {
 	if RUNNING {
 		QUIT = true
 		RESTART <- true
+		// Safety Sleep (Ensure shutdown tasks get done)
+		time.Sleep(time.Second)
 	}
 	os.Remove(SOCK)
 }