[router] Introduce router integration tests (#10086)

sgl-router/py_test/integration/conftest.py

@@ -0,0 +1,109 @@
+import os
+import subprocess
+import time
+from pathlib import Path
+from typing import Dict, Iterable, List, Tuple
+
+import pytest
+import requests
+
+from ..fixtures.ports import find_free_port
+from ..fixtures.router_manager import RouterManager
+
+
+def pytest_configure(config):
+    config.addinivalue_line("markers", "integration: mark as router integration test")
+
+
+@pytest.fixture
+def router_manager() -> Iterable[RouterManager]:
+    mgr = RouterManager()
+    try:
+        yield mgr
+    finally:
+        mgr.stop_all()
+
+
+def _spawn_mock_worker(args: List[str]) -> Tuple[subprocess.Popen, str, str]:
+    repo_root = Path(__file__).resolve().parents[2]
+    script = repo_root / "py_test" / "fixtures" / "mock_worker.py"
+    port = find_free_port()
+    worker_id = f"worker-{port}"
+    base_cmd = [
+        "python3",
+        str(script),
+        "--port",
+        str(port),
+        "--worker-id",
+        worker_id,
+    ]
+    cmd = base_cmd + args
+    proc = subprocess.Popen(cmd)
+    url = f"http://127.0.0.1:{port}"
+    _wait_health(url)
+    return proc, url, worker_id
+
+
+def _wait_health(url: str, timeout: float = 10.0):
+    start = time.time()
+    with requests.Session() as s:
+        while time.time() - start < timeout:
+            try:
+                r = s.get(f"{url}/health", timeout=1)
+                if r.status_code == 200:
+                    return
+            except requests.RequestException:
+                pass
+            time.sleep(0.1)
+    raise TimeoutError(f"Mock worker at {url} did not become healthy")
+
+
+@pytest.fixture
+def mock_worker():
+    """Start a single healthy mock worker; yields (process, url, worker_id)."""
+    proc, url, worker_id = _spawn_mock_worker([])
+    try:
+        yield proc, url, worker_id
+    finally:
+        if proc.poll() is None:
+            proc.terminate()
+            try:
+                proc.wait(timeout=3)
+            except subprocess.TimeoutExpired:
+                proc.kill()
+
+
+@pytest.fixture
+def mock_workers():
+    """Factory to start N workers with custom args.
+
+    Usage:
+        procs, urls, ids = mock_workers(n=3, args=["--latency-ms", "5"])  # same args for all
+        ...
+    """
+
+    procs: List[subprocess.Popen] = []
+
+    def _start(n: int, args: List[str] | None = None):
+        args = args or []
+        new_procs: List[subprocess.Popen] = []
+        urls: List[str] = []
+        ids: List[str] = []
+        for _ in range(n):
+            p, url, wid = _spawn_mock_worker(args)
+            procs.append(p)
+            new_procs.append(p)
+            urls.append(url)
+            ids.append(wid)
+        return new_procs, urls, ids
+
+    try:
+        yield _start
+    finally:
+        for p in procs:
+            if p.poll() is None:
+                p.terminate()
+                try:
+                    p.wait(timeout=3)
+                except subprocess.TimeoutExpired:
+                    p.kill()