feat: systemd socket activation support (LISTEN_FDS auto-detect)

[dmaugis]

When gemini-web2api is managed by systemd's socket activation (.socket unit), systemd passes an already-bound socket as FD 3. The process must not call bind() or it fails with EADDRINUSE. This patch detects the activation environment and uses socket.fromfd() instead.

+19 lines / -2 lines — zero flags, zero config. If LISTEN_FDS is absent, behaviour is identical.

diff :
diff
diff --git a/gemini_web2api.py b/gemini_web2api.py
index 3cd6f4b..8b49560 100644
--- a/gemini_web2api.py
+++ b/gemini_web2api.py
@@ -32,6 +32,7 @@ import os
import hashlib
import argparse
import base64
+import socket
from http.server import HTTPServer, BaseHTTPRequestHandler
from socketserver import ThreadingMixIn

@@ -865,8 +866,26 @@ def main():
allow_reuse_address = True

 port = CONFIG["port"]

• server = ThreadedServer((CONFIG["host"], port), GeminiHandler)
• print(f"gemini-web2api v{version}")

• listen_fds = os.environ.get("LISTEN_FDS")
• listen_pid = os.environ.get("LISTEN_PID")
• if listen_fds and listen_pid and int(listen_pid) == os.getpid() and int(listen_fds) > 0:

•    fd = 3
  

•    try:
  

•        sockinfo = socket.fromfd(fd, socket.AF_INET6, socket.SOCK_STREAM).getsockname()
  

•        fam = socket.AF_INET6 if len(sockinfo) == 4 else socket.AF_INET
  

•    except OSError:
  

•        fam = socket.AF_INET
  

•    sock = socket.fromfd(fd, fam, socket.SOCK_STREAM)
  

•    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
  

•    server = ThreadedServer((CONFIG["host"], port), GeminiHandler, bind_and_activate=False)
  

•    server.socket = sock
  

•    server.server_address = (CONFIG["host"], port)
  

•    print(f"gemini-web2api v{__version__} (systemd socket activation)")
  

• else:

•    server = ThreadedServer((CONFIG["host"], port), GeminiHandler)
  

•    print(f"gemini-web2api v{__version__}")
  

Labels : enhancement