Files
hermes-agent/gateway/status.py
teknium1 014a5b712d fix: prevent duplicate gateway instances from running simultaneously
start_gateway() now checks for an existing running instance via PID file
before starting. If another gateway is already running under the same
HERMES_HOME, it refuses to start with a clear error message directing the
user to 'hermes gateway restart' or 'hermes gateway stop'.

Also fixes gateway/status.py to respect the HERMES_HOME env var instead of
hardcoding ~/.hermes. This scopes the PID file per HERMES_HOME directory,
which lays the groundwork for future multi-profile support where distinct
HERMES_HOME directories can run concurrent gateway instances independently.
2026-03-05 20:35:33 -08:00

62 lines
1.9 KiB
Python

"""
Gateway runtime status helpers.
Provides PID-file based detection of whether the gateway daemon is running,
used by send_message's check_fn to gate availability in the CLI.
The PID file lives at ``{HERMES_HOME}/gateway.pid``. HERMES_HOME defaults to
``~/.hermes`` but can be overridden via the environment variable. This means
separate HERMES_HOME directories naturally get separate PID files — a property
that will be useful when we add named profiles (multiple agents running
concurrently under distinct configurations).
"""
import os
from pathlib import Path
from typing import Optional
def _get_pid_path() -> Path:
"""Return the path to the gateway PID file, respecting HERMES_HOME."""
home = Path(os.getenv("HERMES_HOME", Path.home() / ".hermes"))
return home / "gateway.pid"
def write_pid_file() -> None:
"""Write the current process PID to the gateway PID file."""
pid_path = _get_pid_path()
pid_path.parent.mkdir(parents=True, exist_ok=True)
pid_path.write_text(str(os.getpid()))
def remove_pid_file() -> None:
"""Remove the gateway PID file if it exists."""
try:
_get_pid_path().unlink(missing_ok=True)
except Exception:
pass
def get_running_pid() -> Optional[int]:
"""Return the PID of a running gateway instance, or ``None``.
Checks the PID file and verifies the process is actually alive.
Cleans up stale PID files automatically.
"""
pid_path = _get_pid_path()
if not pid_path.exists():
return None
try:
pid = int(pid_path.read_text().strip())
os.kill(pid, 0) # signal 0 = existence check, no actual signal sent
return pid
except (ValueError, ProcessLookupError, PermissionError):
# Stale PID file — process is gone
remove_pid_file()
return None
def is_gateway_running() -> bool:
"""Check if the gateway daemon is currently running."""
return get_running_pid() is not None