Adding docker healthcheck

README.md

@@ -104,8 +104,23 @@ On a `Intel(R) Xeon(R) E-2288G CPU @ 3.70GHz` (16 core), it will sustain 150 con
 
 Most of the CPU load seems to occur when starting a browser, maybe in the future 1 browser could processes multiple requests.
 
+### Docker healthcheck
+
+Add this to your `docker-compose.yml`, it will check port 3000 answers and that the `/stats` endpoint on port 8080 responds
+
+```
+    healthcheck:
+      test:
+        CMD-SHELL: python3 /usr/src/app/docker-health-check.py --host http://localhost
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 10s
+```
+
 ### Future ideas
 
 - Some super cool "on the wire" hacks to add custom functionality to CDP, like issuing single commands to download files (PDF) to location https://github.com/dgtlmoon/changedetection.io/issues/2019
 
+
 Have fun!

backend/docker-health-check.py

@@ -0,0 +1,52 @@
+#!/usr/bin/python3
+
+import sys
+import socket
+import urllib.request
+import argparse
+from urllib.parse import urlparse
+
+def main():
+    parser = argparse.ArgumentParser(description='Health check script')
+    parser.add_argument(
+        '--host',
+        default='http://localhost',
+        help='Hostname or URL to check (default: http://localhost)'
+    )
+    args = parser.parse_args()
+
+    # Extract hostname and scheme from the provided host argument
+    host_input = args.host
+
+    # Parse the URL to extract components
+    parsed_url = urlparse(host_input)
+
+    # If scheme is missing, assume 'http' and parse again
+    if not parsed_url.scheme:
+        host_input = f'http://{host_input}'
+        parsed_url = urlparse(host_input)
+
+    hostname = parsed_url.hostname or 'localhost'
+    scheme = parsed_url.scheme or 'http'
+    netloc = parsed_url.netloc or 'localhost'
+
+    # Reconstruct the base URL without any path, params, query, or fragment
+    base_url = f'{scheme}://{netloc}'
+
+    try:
+        # Strip 'http://' or 'https://' for socket connection
+        # Check connection to port 3000
+        s = socket.create_connection((hostname, 3000), timeout=5)
+        s.close()
+
+        # Check HTTP status code at /stats on port 8080
+        stats_url = f'{base_url}:8080/stats'
+        response = urllib.request.urlopen(stats_url, timeout=5)
+        sys.exit(0 if response.status == 200 else 1)
+    except Exception as e:
+        # Optionally, print the exception for debugging
+        print(f'Health check failed: {e}', file=sys.stderr)
+        sys.exit(1)
+
+if __name__ == '__main__':
+    main()