refactor slack logger

app/slack.py

@@ -0,0 +1,43 @@
+from pymongo.errors import PyMongoError
+from requests.exceptions import RequestException
+import os
+import requests
+
+SLACK_DOORLOG_CALLBACK = os.environ["SLACK_DOORLOG_CALLBACK"] # webhook logs to private channel or "DEV" to print to console.
+
+def add_slack_routes(app):
+    app.app.register_listener(slack_log, "after_server_start") # consumes SLACK_DOORLOG_CALLBACK and app.ctx.db
+
+def slack_post(msg):
+    if SLACK_DOORLOG_CALLBACK == "DEV":
+        print(f"[DEV SLACK]: {msg}")
+        return
+
+    try:
+        requests.post(SLACK_DOORLOG_CALLBACK, json={"text": msg }).raise_for_status()
+    except RequestException as e:
+        print(f"[SLACK]: {e}")
+
+def approvedStr(approved: bool) -> str:
+    if approved:
+        return "Permitted"
+    
+    return "Denied"
+
+async def slack_log(app, loop):
+    pipeline = [{
+        "$match": {
+            "operationType": "insert",
+        }
+    }]
+    while True:
+        try:
+            async with app.ctx.db.eventlog.watch(pipeline) as stream:
+                async for event in stream:
+                    ev = event["fullDocument"]
+                    
+                    msg = "%s %s access for %s via %s" % (approvedStr(ev["approved"]), ev["door"], ev["user"]["name"], ev("method"))
+                    slack_post(msg)
+        
+        except PyMongoError as e:
+            print(e)