Files
Fenris/src/fenris/collect.py
T

138 lines
3.8 KiB
Python

#!/usr/bin/env python3
"""fenris-collect: device interrogation and store writes.
This is the root oneshot unit's ExecStart. It reads the device selector
from /etc/fenris/fenris.conf, interrogates the drive via smartctl and sysfs,
and writes the sample to the observation store.
Spec: §8.4, §8.5
When run as a script, uses the fenris package from the installed wheel.
"""
import json
import subprocess
import sys
from datetime import datetime, timezone
from pathlib import Path
# Package dependencies are vendored independently of the host Python minor
# version. Keep the venv fallback for the legacy development install.
VENV_DIR = Path("/opt/fenris")
if VENV_DIR.exists():
vendor_dir = VENV_DIR / "vendor"
if vendor_dir.is_dir():
sys.path.insert(0, str(vendor_dir))
else:
site_packages = next((VENV_DIR / "lib").glob("python*/site-packages"), None)
if site_packages:
sys.path.insert(0, str(site_packages))
from fenris.store import init_store, get_store_path
from fenris.collector import run_collection
CONFIG_PATH = Path("/etc/fenris/fenris.conf")
def load_config() -> dict:
"""Load configuration from /etc/fenris/fenris.conf.
The file holds exactly one key: the device selector.
Spec §8.3: re-read every run; no reload path.
"""
if not CONFIG_PATH.exists():
raise RuntimeError(f"Configuration file not found: {CONFIG_PATH}")
config = {}
try:
with open(CONFIG_PATH, "r") as f:
for line in f:
line = line.strip()
if not line or line.startswith("#"):
continue
if "=" in line:
key, value = line.split("=", 1)
config[key.strip()] = value.strip()
except Exception as e:
raise RuntimeError(f"Failed to read configuration: {e}")
if "device" not in config:
raise RuntimeError("Configuration error: missing 'device' key")
return config
def interrogate_drive(device: str) -> dict:
"""Interrogate the drive via smartctl.
Returns the smartctl JSON output.
Raises RuntimeError on failure.
"""
result = subprocess.run(
["smartctl", "-a", "-j", device],
capture_output=True,
text=True,
)
if result.returncode != 0:
raise RuntimeError(
f"smartctl failed for {device}: {result.stderr}"
)
try:
return json.loads(result.stdout)
except json.JSONDecodeError as e:
raise RuntimeError(f"Failed to parse smartctl output: {e}")
def find_nvme_sysfs() -> Path | None:
"""Find the NVMe controller sysfs path."""
nvme_ctrl = Path("/sys/class/nvme")
if not nvme_ctrl.exists():
return None
for ctrl in sorted(nvme_ctrl.iterdir()):
if ctrl.name.startswith("nvme"):
return ctrl
return None
def main() -> None:
"""Run one collection cycle."""
try:
config = load_config()
device = config["device"]
# Interrogate the drive
smartctl_data = interrogate_drive(device)
# Find sysfs path
sysfs_path = find_nvme_sysfs()
if sysfs_path is None:
raise RuntimeError("No NVMe controller found in sysfs")
# Inject a simple clock
class SimpleClock:
def utcnow(self):
return datetime.now(timezone.utc)
clock = SimpleClock()
# Run collection
result = run_collection(smartctl_data, sysfs_path, config, clock)
if result["ok"]:
print(f"Collection successful: {result['sample_count']} sample(s)")
sys.exit(0)
else:
print(f"Collection failed: {result['error']}", file=sys.stderr)
sys.exit(1)
except Exception as e:
print(f"Collection error: {e}", file=sys.stderr)
sys.exit(1)
if __name__ == "__main__":
main()