Add CLI monitoring commands

docs/router_api.md

@@ -222,3 +222,17 @@ The router exposes Prometheus metrics at `/metrics`. Basic counters
 track request volume, latency and cache hits. Logs are written to
 `logs/router.log` and rotated daily. Configure the log level via the
 `LOG_LEVEL` environment variable.
+
+Tail the log file using the CLI:
+
+```bash
+python -m router.cli show-logs --no-follow
+```
+
+Use `--follow` to stream updates or pass a custom path.
+
+Export metrics in Prometheus format:
+
+```bash
+python -m router.cli export-metrics
+```

router/cli.py

@@ -5,6 +5,7 @@
 import json
 import os
 from pathlib import Path
+import time
 
 import httpx
 import typer
@@ -103,5 +104,45 @@ def refresh_openai() -> None:
     typer.echo(f"Inserted {len(data)} models")
 
 
+@app.command("show-logs")
+def show_logs(
+    path: Path | None = typer.Argument(None),
+    follow: bool = True,
+) -> None:
+    """Tail the router log file."""
+
+    file_path = (
+        path if path is not None else Path(os.getenv("LOG_PATH", "logs/router.log"))
+    )
+    if not file_path.exists():
+        typer.echo(f"Log file '{file_path}' not found", err=True)
+        raise typer.Exit(1)
+
+    with file_path.open() as fh:
+        if follow:
+            fh.seek(0, os.SEEK_END)
+            try:
+                while True:
+                    line = fh.readline()
+                    if not line:
+                        time.sleep(0.5)
+                        continue
+                    typer.echo(line, nl=False)
+            except KeyboardInterrupt:
+                pass
+        else:
+            for line in fh:
+                typer.echo(line, nl=False)
+
+
+@app.command("export-metrics")
+def export_metrics(url: str = "http://localhost:8000/metrics") -> None:
+    """Fetch metrics from the router and print them."""
+
+    resp = httpx.get(url, timeout=10)
+    resp.raise_for_status()
+    typer.echo(resp.text)
+
+
 if __name__ == "__main__":
     app()

tests/router/test_cli_logs_metrics.py

@@ -0,0 +1,26 @@
+from typer.testing import CliRunner
+import router.cli as cli
+
+
+def test_show_logs(tmp_path):
+    log_file = tmp_path / "router.log"
+    log_file.write_text("line1\nline2\n")
+    runner = CliRunner()
+    result = runner.invoke(cli.app, ["show-logs", str(log_file), "--no-follow"])
+    assert result.exit_code == 0
+    assert "line1" in result.stdout
+    assert "line2" in result.stdout
+
+
+def test_export_metrics(monkeypatch):
+    class Resp:
+        text = "router_requests_total 1"
+
+        def raise_for_status(self):
+            pass
+
+    monkeypatch.setattr(cli.httpx, "get", lambda url, timeout=10: Resp())
+    runner = CliRunner()
+    result = runner.invoke(cli.app, ["export-metrics"])
+    assert result.exit_code == 0
+    assert "router_requests_total" in result.stdout