From 6803a473dc107fa8c215ea316d2fc174c09d57a0 Mon Sep 17 00:00:00 2001
From: Waldemar Hummer <waldemar.hummer@gmail.com>
Date: Fri, 30 Jul 2021 07:20:45 +0200
Subject: [PATCH] add exception handling to signal handlers if moto is started
 from non-main thread (#4112)

---
 moto/server.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/moto/server.py b/moto/server.py
index e1580ca6e..a0db1fdf9 100644
--- a/moto/server.py
+++ b/moto/server.py
@@ -297,8 +297,11 @@ def main(argv=sys.argv[1:]):
 
     args = parser.parse_args(argv)
 
-    signal.signal(signal.SIGINT, signal_handler)
-    signal.signal(signal.SIGTERM, signal_handler)
+    try:
+        signal.signal(signal.SIGINT, signal_handler)
+        signal.signal(signal.SIGTERM, signal_handler)
+    except Exception:
+        pass  # ignore "ValueError: signal only works in main thread"
 
     # Wrap the main application
     main_app = DomainDispatcherApplication(create_backend_app, service=args.service)