chore(test): declutter router common.py into helper and router_process modules (#7210)

Signed-off-by: PeaBrane <yanrpei@gmail.com>

tests/router/router_process.py

+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import os
+
+from tests.utils.managed_process import ManagedProcess
+
+
+class KVRouterProcess(ManagedProcess):
+    """Manages the KV router process using dynamo.frontend"""
+
+    def __init__(
+        self,
+        request,
+        block_size: int,
+        frontend_port: int,
+        namespace: str,
+        store_backend: str = "etcd",
+        enforce_disagg: bool = False,
+        blocks_threshold: float | None = None,
+        tokens_threshold: float | None = None,
+        tokens_threshold_frac: float | None = None,
+        request_plane: str = "nats",
+        durable_kv_events: bool = False,
+    ):
+        command = [
+            "python3",
+            "-m",
+            "dynamo.frontend",
+            "--kv-cache-block-size",
+            str(block_size),
+            "--router-mode",
+            "kv",
+            "--http-port",
+            str(frontend_port),
+            "--discovery-backend",
+            store_backend,
+            "--namespace",
+            namespace,
+        ]
+
+        if enforce_disagg:
+            command.append("--enforce-disagg")
+
+        if blocks_threshold is not None:
+            command.extend(["--active-decode-blocks-threshold", str(blocks_threshold)])
+
+        if tokens_threshold is not None:
+            command.extend(["--active-prefill-tokens-threshold", str(tokens_threshold)])
+
+        if tokens_threshold_frac is not None:
+            command.extend(
+                ["--active-prefill-tokens-threshold-frac", str(tokens_threshold_frac)]
+            )
+
+        if durable_kv_events:
+            command.append("--router-durable-kv-events")
+
+        env = os.environ.copy()
+        env["DYN_REQUEST_PLANE"] = request_plane
+
+        super().__init__(
+            command=command,
+            env=env,
+            timeout=60,
+            display_output=True,
+            health_check_ports=[frontend_port],
+            health_check_urls=[
+                (f"http://localhost:{frontend_port}/v1/models", self._check_ready)
+            ],
+            log_dir=request.node.name,
+            terminate_all_matching_process_names=False,
+        )
+        self.port = frontend_port
+
+    def _check_ready(self, response):
+        """Check if KV router is ready"""
+        return response.status_code == 200
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        super().__exit__(exc_type, exc_val, exc_tb)

tests/router/test_router_e2e_with_mockers.py

@@ -20,7 +20,7 @@ from typing import Any, Dict, Optional
 import aiohttp
 import pytest
 
-from tests.router.common import (  # utilities
+from tests.router.common import (
     _test_busy_threshold_endpoint,
     _test_python_router_bindings,
     _test_router_basic,
@@ -30,9 +30,8 @@ from tests.router.common import (  # utilities
     _test_router_overload_503,
     _test_router_query_instance_id,
     _test_router_two_routers,
-    generate_random_suffix,
-    get_runtime,
 )
+from tests.router.helper import generate_random_suffix, get_runtime
 from tests.utils.constants import ROUTER_MODEL_NAME
 from tests.utils.managed_process import ManagedProcess
 from tests.utils.port_utils import allocate_ports, deallocate_ports

tests/router/test_router_e2e_with_sglang.py

@@ -12,13 +12,12 @@ from typing import Any, Dict, Optional
 
 import pytest
 
-from tests.router.common import (  # utilities
+from tests.router.common import (
     _test_router_basic,
     _test_router_decisions,
     _test_router_indexers_sync,
-    generate_random_suffix,
-    get_runtime,
 )
+from tests.router.helper import generate_random_suffix, get_runtime
 from tests.utils.constants import DefaultPort
 from tests.utils.managed_process import ManagedProcess
 from tests.utils.port_utils import allocate_ports, deallocate_ports

tests/router/test_router_e2e_with_trtllm.py

@@ -12,13 +12,12 @@ from typing import Any, Dict, Optional
 
 import pytest
 
-from tests.router.common import (  # utilities
+from tests.router.common import (
     _test_router_basic,
     _test_router_decisions,
     _test_router_indexers_sync,
-    generate_random_suffix,
-    get_runtime,
 )
+from tests.router.helper import generate_random_suffix, get_runtime
 from tests.utils.constants import DefaultPort
 from tests.utils.managed_process import ManagedProcess
 from tests.utils.port_utils import allocate_ports, deallocate_ports

tests/router/test_router_e2e_with_vllm.py

@@ -13,13 +13,12 @@ from typing import Any, Dict, Optional
 
 import pytest
 
-from tests.router.common import (  # utilities
+from tests.router.common import (
     _test_router_basic,
     _test_router_decisions,
     _test_router_indexers_sync,
-    generate_random_suffix,
-    get_runtime,
 )
+from tests.router.helper import generate_random_suffix, get_runtime
 from tests.utils.constants import DefaultPort
 from tests.utils.managed_process import ManagedProcess
 from tests.utils.port_utils import allocate_ports, deallocate_ports