Refactor request listeners to use async functions

bin/genieacs-ui.ts

@@ -84,8 +84,6 @@ if (!cluster.worker) {
     timeout: 30000,
   };
 
-  let stopping = false;
-
   process.on("uncaughtException", (err) => {
     if ((err as NodeJS.ErrnoException).code === "ERR_IPC_DISCONNECTED") return;
     logger.error({
@@ -93,19 +91,13 @@ if (!cluster.worker) {
       exception: err,
       pid: process.pid,
     });
-    stopping = true;
     server.stop().then(exitWorkerGracefully).catch(exitWorkerUngracefully);
   });
 
-  const _listener = (req, res): void => {
-    if (stopping) res.setHeader("Connection", "close");
-    listener(req, res);
-  };
-
   const initPromise = db
     .connect()
     .then(() => {
-      server.start(options, _listener);
+      server.start(options, async (req, res) => listener(req, res));
     })
     .catch((err) => {
       setTimeout(() => {
@@ -114,14 +106,12 @@ if (!cluster.worker) {
     });
 
   process.on("SIGINT", () => {
-    stopping = true;
     initPromise.finally(() => {
       server.stop().then(exitWorkerGracefully).catch(exitWorkerUngracefully);
     });
   });
 
   process.on("SIGTERM", () => {
-    stopping = true;
     initPromise.finally(() => {
       server.stop().then(exitWorkerGracefully).catch(exitWorkerUngracefully);
     });