Improve error handling.

app.py

@@ -197,6 +197,11 @@ def update_servers_background():
 update_thread = threading.Thread(target=update_servers_background, daemon=True)
 update_thread.start()
 
+@app.errorhandler(Exception)
+def handle_unexpected_error(error):
+    print(f"Unhandled error: {error}", flush=True)
+    return jsonify({"error": "Internal server error"}), 500
+
 @app.route('/')
 def index():
     return send_from_directory('static', 'index.html')
@@ -209,7 +214,9 @@ def get_servers():
 @app.route('/api/update-locations', methods=['POST'])
 def update_locations_endpoint():
     try:
-        generate_locations()
+        ok = generate_locations()
+        if not ok:
+            raise RuntimeError("Location generation failed")
         
         load_cache()
         
@@ -255,4 +262,5 @@ def run_test():
 
 if __name__ == '__main__':
     load_cache()
-    app.run(host='0.0.0.0', port=5000, debug=True)
+    debug_enabled = os.getenv('FLASK_DEBUG', '0') == '1'
+    app.run(host='0.0.0.0', port=5000, debug=debug_enabled)

docker-compose.yml

@@ -3,4 +3,6 @@ services:
     build: .
     ports:
       - "5000:5000"
+    environment:
+      - FLASK_DEBUG=0
     restart: unless-stopped

generate_locations.py

@@ -31,7 +31,7 @@ def generate_locations():
         servers = response.json()
     except Exception as e:
         print(f"Failed to fetch server list: {e}")
-        return
+        raise RuntimeError(f"Failed to fetch server list: {e}") from e
 
     print(f"Found {len(servers)} servers.")
 
@@ -95,10 +95,15 @@ def generate_locations():
     
     sorted_results = dict(sorted(results.items()))
     
-    with open('prefilled_locations.json', 'w', encoding='utf-8') as f:
-        json.dump(sorted_results, f, indent=2)
+    try:
+        with open('prefilled_locations.json', 'w', encoding='utf-8') as f:
+            json.dump(sorted_results, f, indent=2)
+    except Exception as e:
+        print(f"Failed to write prefilled_locations.json: {e}")
+        raise RuntimeError(f"Failed to write prefilled_locations.json: {e}") from e
         
     print("Saved to prefilled_locations.json")
+    return True
 
 if __name__ == "__main__":
     sys.stdout = open('gen_log.txt', 'w', encoding='utf-8')

static/script.js

@@ -144,7 +144,22 @@ document.addEventListener('DOMContentLoaded', () => {
             updateBtn.disabled = true;
 
             fetch('/api/update-locations', { method: 'POST' })
-                .then(res => res.json())
+                .then(async res => {
+                    const contentType = res.headers.get('content-type') || '';
+                    if (contentType.includes('application/json')) {
+                        const data = await res.json();
+                        if (!res.ok) {
+                            throw new Error(data.error || `HTTP ${res.status}`);
+                        }
+                        return data;
+                    }
+
+                    const text = await res.text();
+                    if (!res.ok) {
+                        throw new Error(text || `HTTP ${res.status}`);
+                    }
+                    throw new Error(text || 'Unexpected non-JSON response');
+                })
                 .then(data => {
                     if (data.error) {
                         alert("Error: " + data.error);