From 8f8f88540e24b13df6ee878201f3295df77d574b Mon Sep 17 00:00:00 2001
From: "Adam J. Weigold" <adam@adamweigold.com>
Date: Wed, 12 Nov 2025 10:43:29 -0600
Subject: [PATCH] Reduced zombie processes when running in a container by
 utilizing a python requests based health check that can reap stalled checks. 
 Fixed the health endpoint.  Added SIGCHLD handler to main process to reap
 terminated child processes.

---
 Dockerfile |  5 +++--
 main.py    | 24 ++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 77dc10c6..f1dc9e46 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -30,9 +30,10 @@ ENV TZ=UTC
 # Expose port
 EXPOSE 9705
 
-# Add health check for Docker
+# Add health check for Docker using Python to avoid spawning curl processes
+# The SIGCHLD handler in main.py will reap any terminated health check processes
 HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
-    CMD curl -f http://localhost:9705/health || exit 1
+    CMD ["python3", "-c", "import requests; import sys; r = requests.get('http://localhost:9705/api/health', timeout=5); sys.exit(0 if r.status_code == 200 else 1)"]
 
 # Run the main application using the new entry point
 CMD ["python3", "main.py"]
\ No newline at end of file
diff --git a/main.py b/main.py
index c6d486ea..793bfdae 100644
--- a/main.py
+++ b/main.py
@@ -324,11 +324,28 @@ def run_web_server():
             if not stop_event.is_set():
                 stop_event.set()
 
+def sigchld_handler(signum, frame):
+    """Handle SIGCHLD to prevent zombie processes."""
+    # Reap all terminated child processes without blocking
+    while True:
+        try:
+            # WNOHANG returns immediately if no child has exited
+            pid, status = os.waitpid(-1, os.WNOHANG)
+            if pid == 0:
+                # No more zombie children
+                break
+        except ChildProcessError:
+            # No child processes
+            break
+        except OSError:
+            # Error occurred, stop trying
+            break
+
 def main_shutdown_handler(signum, frame):
     """Gracefully shut down the application."""
     global _global_shutdown_flag
     _global_shutdown_flag = True  # Set global shutdown flag immediately
-    
+
     signal_name = "SIGINT" if signum == signal.SIGINT else "SIGTERM" if signum == signal.SIGTERM else f"Signal {signum}"
     huntarr_logger.info(f"Received {signal_name}. Initiating graceful shutdown...")
     
@@ -440,7 +457,10 @@ def main():
     # Register signal handlers for graceful shutdown in the main process
     signal.signal(signal.SIGINT, main_shutdown_handler)
     signal.signal(signal.SIGTERM, main_shutdown_handler)
-    
+
+    # Register SIGCHLD handler to prevent zombie processes (Docker healthchecks)
+    signal.signal(signal.SIGCHLD, sigchld_handler)
+
     # Register cleanup handler
     atexit.register(cleanup_handler)