alarm: proxy_cloudfront reads max quota from config

app/terraform/alarms/proxy_cloudfront.py

@@ -1,4 +1,3 @@
-import datetime
 from typing import Tuple
 
 import boto3
@@ -14,17 +13,26 @@ from app.terraform import BaseAutomation
 
 
 def _cloudfront_quota() -> None:
-    alarm = get_or_create_alarm(
-        BRN.from_str(f"brn:{current_app.config['GLOBAL_NAMESPACE']}:0:mirror:cloudfront:quota/distributions"),
-        "quota-usage"
-    )
-    alarm.last_updated = datetime.datetime.utcnow()
+    # It would be nice to learn this from the Service Quotas API, however
+    # at the time of writing this comment, the current value for this quota
+    # is not available from the API. It just doesn't return anything.
+    max_count = int(current_app.config.get('AWS_CLOUDFRONT_MAX_DISTRIBUTIONS', 200))
     deployed_count = len(Proxy.query.filter(
         Proxy.destroyed.is_(None)).all())
-    message = f"{deployed_count} distributions deployed"
-    if deployed_count > 370:
+    message = f"{deployed_count} distributions deployed of {max_count} quota"
+    alarm = get_or_create_alarm(
+        BRN(
+            group_id=0,
+            product="mirror",
+            provider="cloudfront",
+            resource_type="quota",
+            resource_id="distributions"
+        ),
+        "quota-usage"
+    )
+    if deployed_count > max_count * 0.9:
         alarm.update_state(AlarmState.CRITICAL, message)
-    elif deployed_count > 320:
+    elif deployed_count > max_count * 0.75:
         alarm.update_state(AlarmState.WARNING, message)
     else:
         alarm.update_state(AlarmState.OK, message)