slo-tracker/slo_tracker.py

72 lines
2.2 KiB
Python

#!/usr/bin/env python3
"""Minimal SLO burn rate tracker for Prometheus."""
import argparse
import sys
from datetime import datetime, timedelta
import yaml
from prometheus_api_client import PrometheusConnect
from rich.console import Console
from rich.table import Table
console = Console()
def load_config(path: str) -> dict:
with open(path) as f:
return yaml.safe_load(f)
def evaluate_slo(prom: PrometheusConnect, slo: dict, window: str) -> dict:
result = prom.custom_query(slo["query"])
if not result:
return {"name": slo["name"], "value": None, "target": slo["target"], "ok": False}
value = float(result[0]["value"][1])
return {
"name": slo["name"],
"value": value,
"target": slo["target"],
"ok": value >= slo["target"],
}
def main():
parser = argparse.ArgumentParser(description="SLO burn rate tracker")
parser.add_argument("--config", required=True)
parser.add_argument("--prometheus", default="http://localhost:9090")
parser.add_argument("--window", default="7d")
args = parser.parse_args()
cfg = load_config(args.config)
prom = PrometheusConnect(url=args.prometheus, disable_ssl=True)
table = Table(title=f"SLO Status ({args.window} window)")
table.add_column("SLO", style="cyan")
table.add_column("Target", justify="right")
table.add_column("Current", justify="right")
table.add_column("Status", justify="center")
all_ok = True
for slo in cfg.get("slos", []):
result = evaluate_slo(prom, slo, args.window)
status = "[green]OK[/green]" if result["ok"] else "[red]BURNING[/red]"
value_str = f"{result['value']:.4f}" if result["value"] is not None else "n/a"
table.add_row(result["name"], str(result["target"]), value_str, status)
if not result["ok"]:
all_ok = False
console.print(table)
sys.exit(0 if all_ok else 1)
if __name__ == "__main__":
main()
def burn_rate(error_rate: float, window_hours: float, target: float) -> float:
"""Calculate burn rate: how fast the error budget is being consumed."""
budget = 1.0 - target
if budget == 0:
return float("inf")
return error_rate / budget * (window_hours / (30 * 24))