Add subscription event source plugin (DCNE-269)

.gitignore

@@ -390,5 +390,8 @@ $RECYCLE.BIN/
 # vsCode
 .vscode
 
+# Python venv
+venv/
+
 # Ansible Collection tarball
 cisco-aci-*.tar.gz

extensions/eda/plugins/event_source/subscription.py

@@ -0,0 +1,148 @@
+"""
+subscription.py
+
+An ansible-rulebook event source plugin template.
+
+Arguments:
+  - apic1: APIC IP or hostname
+  - username: APIC username
+  - password: APIC password
+  - subscriptions: query api endpoints for subscriptions
+  - refresh_timeout: (optional) timeout of subscription
+
+Examples:
+  cisco.aci_eda.websocket:
+    hostname: apic1
+    username: ansible
+    password: ansible
+    subscriptions:
+        - /api/mo/uni/tn-demo/ap-demo/epg-demo.json?query-target=children&target-subtree-class=fvCEp&query-target=subtree
+    refresh_timeout: 60
+
+"""
+
+import asyncio
+import json
+import os
+import sys
+import signal
+import ssl
+from typing import Any, Dict, NoReturn
+import requests
+import websockets
+import urllib3
+
+urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
+
+
+def login(hostname: str, username: str, password: str) -> str:
+    """
+    login to apic and get session token
+
+    :param hostname: apic hostname or ip
+    :param username: apic username
+    :param password: apic password
+    :return: session token
+    """
+    login_url = f"https://{hostname}/api/aaaLogin.json"
+    payload = {"aaaUser": {"attributes": {"name": username, "pwd": password}}}
+    token = ""
+
+    login_response = requests.post(login_url, json=payload, verify=False)
+    if login_response.ok:
+        response_json = login_response.json()
+        token = response_json["imdata"][0]["aaaLogin"]["attributes"]["token"]
+    return token
+
+
+def subscribe(hostname: str, token: str, rf_timeout: int, sub_urls: list[str]) -> list[str]:
+    """
+    subscribe to a websocket
+
+    :param hostname: apic hostname or ip
+    :param token: apic session token
+    :param rf_timeout: refresh timeout of subscription
+    :param sub_urls: subscriptions url
+    :return: list of subscription ids
+    """
+    sub_ids = []
+
+    for sub in sub_urls:
+        sub_url = f"https://{hostname}{sub}&subscription=yes&refresh-timeout={rf_timeout}"
+        cookie = {"APIC-cookie": token}
+        sub_response = requests.get(sub_url, verify=False, cookies=cookie, timeout=60)
+        if sub_response.ok:
+            sub_id = sub_response.json()["subscriptionId"]
+            sub_ids.append(sub_id)
+    return sub_ids
+
+
+async def refresh(hostname: str, token: str, refresh_timeout: int, sub_ids: list[str]) -> NoReturn:
+    """
+    refresh subscriptions
+
+    :param hostname: apic hostname or ip
+    :param token: session token
+    :param refresh_timeout: subscription refresh timeout
+    :param sub_ids: subscription ids
+    :return: NoReturn
+    """
+    cookie = {"APIC-cookie": token}
+    while True:
+        await asyncio.sleep(refresh_timeout / 2)
+        for sub_id in sub_ids:
+            refresh_url = f"https://{hostname}/api/subscriptionRefresh.json?id={sub_id}"
+            requests.get(refresh_url, verify=False, cookies=cookie, timeout=60)
+
+
+async def main(queue: asyncio.Queue, args: Dict[str, Any]):
+    hostname = args.get("hostname", "")
+    username = args.get("username", "")
+    password = args.get("password", "")
+    refresh_timeout = int(args.get("refresh_timeout", 300))
+    subscriptions = args.get("subscriptions")
+
+    if "" in [hostname, username, password]:
+        print(f"hostname, username and password can't be empty:{hostname}, {username}, *****")
+        sys.exit(1)
+
+    if not isinstance(subscriptions, list) or subscriptions == [] or subscriptions is None:
+        print(f"subscriptions is empty or not a list: {subscriptions}")
+        sys.exit(1)
+
+    token = login(hostname=hostname, username=username, password=password)
+    websocket_uri = f"wss://{hostname}/socket{token}"
+    ctx = ssl.SSLContext()
+
+    async with websockets.connect(websocket_uri, ssl=ctx) as ws:
+        loop = asyncio.get_running_loop()
+        loop.add_signal_handler(signal.SIGTERM, lambda: loop.create_task(ws.close()))
+        sub_ids = subscribe(hostname, token, refresh_timeout, subscriptions)
+
+        # task to refresh subscription token
+        asyncio.create_task(refresh(hostname, token, refresh_timeout, sub_ids))
+
+        async for message in ws:
+            await queue.put(json.loads(message))
+
+
+if __name__ == "__main__":
+    # this function is conly called when executed directly
+    apic_username = os.environ["apic_username"]
+    apic_password = os.environ["apic_password"]
+    apic_url = os.environ["apic_url"]
+
+    class MockQueue(asyncio.Queue):
+        async def put(self, item):
+            print(item)
+
+    mock_arguments = {
+        "hostname": apic_url,
+        "username": apic_username,
+        "password": apic_password,
+        "subscriptions": [
+            '/api/node/class/faultInst.json?query-target-filter=and(eq(faultInst.code,"F1386"))',
+        ],
+        "refresh_timeout": 30,
+    }
+    asyncio.run(main(MockQueue(), mock_arguments))

requirements.txt

@@ -3,3 +3,6 @@ cryptography
 pyOpenSSL
 python_dateutil
 xmljson
+requests
+websockets
+asyncmock

tests/unit/event_source/test_subscription.py

@@ -0,0 +1,79 @@
+from unittest.mock import patch
+from typing import Any, List
+from asyncmock import AsyncMock
+from extensions.eda.plugins.event_source.subscription import main as subscription_main
+import pytest
+import json
+import asyncio
+
+
+# Refresh mock method
+def refresh_patch(hostname: str, token: str, rf_timeout: int, sub_urls: List[str]) -> None:
+    pass
+
+
+# Login mock method
+def login_patch(hostname: str, username: str, password: str) -> str:
+    return f"{hostname}{username}{password}"
+
+
+# Subscribe mock method
+def subscribe_patch(hostname, token, rf_timeout, sub_urls) -> List[str]:
+    return [f"{hostname}{token}{rf_timeout}{url}" for url in sub_urls]
+
+
+# Mock iterator
+class AsyncIterator:
+    def __init__(self) -> None:
+        self.count = 0
+
+    async def __anext__(self) -> str:
+        if self.count < 2:
+            self.count += 1
+            return json.dumps({"eventid": f"00{self.count}"})
+        else:
+            raise StopAsyncIteration
+
+
+# Mock Async Websocket
+class MockWebSocket(AsyncMock):  # type: ignore[misc]
+    def __aiter__(self) -> AsyncIterator:
+        return AsyncIterator()
+
+    async def close(self) -> None:
+        pass
+
+
+# Mock AsyncQueue
+class MockQueue(asyncio.Queue[Any]):
+    def __init__(self) -> None:
+        self.queue: list[Any] = []
+
+    async def put(self, item: Any) -> None:
+        self.queue.append(item)
+
+
+def test_websocket_subscription() -> None:
+
+    with patch(
+        "websockets.connect",
+        return_value=MockWebSocket(),
+    ), patch("unit.event_source.tmp_subscription.login", return_value=login_patch), patch(
+        "unit.event_source.tmp_subscription.subscribe", return_value=subscribe_patch
+    ), patch("unit.event_source.tmp_subscription.refresh", return_value=refresh_patch):
+
+        my_queue = MockQueue()
+        asyncio.run(
+            subscription_main(
+                my_queue,
+                {
+                    "hostname": "my-apic.com",
+                    "username": "admin",
+                    "password": "admin",
+                    "subscriptions": ['/api/node/class/faultInst.json?query-target-filter=and(eq(faultInst.code,"F1386"))'],
+                },
+            )
+        )
+
+        assert my_queue.queue[0] == {"eventid": "001"}
+        assert len(my_queue.queue) == 2