added multi node functionality

app/services/pls.py

@@ -0,0 +1,78 @@
+"""PLS API client for cluster and per-node discovery."""
+
+from __future__ import annotations
+
+from urllib.parse import urlsplit, urlunsplit
+
+import httpx
+
+from app.config import PLS_AUTH_BACKEND, PLS_BASE_URL, PLS_PASSWORD, PLS_USERNAME, PLS_VERIFY_TLS
+
+_token: str | None = None
+
+
+def _base_url_for_host(host: str | None = None) -> str:
+    if not host:
+        return PLS_BASE_URL.rstrip("/")
+    parts = urlsplit(PLS_BASE_URL)
+    return urlunsplit((parts.scheme, host, parts.path.rstrip("/"), "", ""))
+
+
+async def _login() -> str | None:
+    global _token
+    if _token:
+        return _token
+    if not PLS_USERNAME or not PLS_PASSWORD:
+        return None
+
+    try:
+        async with httpx.AsyncClient(timeout=5, verify=PLS_VERIFY_TLS) as client:
+            response = await client.post(
+                f"{_base_url_for_host()}/auth/login",
+                json={
+                    "username": PLS_USERNAME,
+                    "password": PLS_PASSWORD,
+                    "backend": PLS_AUTH_BACKEND,
+                },
+            )
+            response.raise_for_status()
+            data = response.json()
+            _token = data.get("access_token")
+            return _token
+    except Exception:
+        return None
+
+
+async def _get(path: str, host: str | None = None) -> dict | list | None:
+    token = await _login()
+    if not token:
+        return None
+
+    headers = {"Authorization": f"Bearer {token}"}
+    url = f"{_base_url_for_host(host)}/{path.lstrip('/')}"
+    try:
+        async with httpx.AsyncClient(timeout=5, verify=PLS_VERIFY_TLS) as client:
+            response = await client.get(url, headers=headers)
+            response.raise_for_status()
+            return response.json()
+    except Exception:
+        return None
+
+
+def node_host(node_name: str) -> str:
+    return node_name.split("@", 1)[1] if "@" in node_name else node_name
+
+
+async def get_cluster_status() -> dict | None:
+    data = await _get("data_layer/cluster/status")
+    return data if isinstance(data, dict) else None
+
+
+async def get_system_info(host: str | None = None) -> dict | None:
+    data = await _get("system/info", host=host)
+    return data if isinstance(data, dict) else None
+
+
+async def get_services(host: str | None = None) -> list[dict]:
+    data = await _get("services", host=host)
+    return data if isinstance(data, list) else []