Merge: + config: add "rlimit_nofile" setting - Maximum number of opened fd's per process

* commit '1f1e26f67b00ee4983c65e4e3aabf59a488f687b':
  + config: add "rlimit_nofile" setting - Maximum number of opened fd's per process

app.go

@@ -95,6 +95,11 @@ func run(args options) {
 		log.Fatal(err)
 	}
 
+	if (runtime.GOOS == "linux" || runtime.GOOS == "darwin") &&
+		config.RlimitNoFile != 0 {
+		setRlimit(config.RlimitNoFile)
+	}
+
 	// override bind host/port from the console
 	if args.bindHost != "" {
 		config.BindHost = args.bindHost
@@ -303,6 +308,18 @@ func enableTLS13() {
 	}
 }
 
+// Set user-specified limit of how many fd's we can use
+// https://github.com/AdguardTeam/AdGuardHome/issues/659
+func setRlimit(val uint) {
+	var rlim syscall.Rlimit
+	rlim.Max = uint64(val)
+	rlim.Cur = uint64(val)
+	err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlim)
+	if err != nil {
+		log.Error("Setrlimit() failed: %v", err)
+	}
+}
+
 func cleanup() {
 	log.Info("Stopping AdGuard Home")