feat: Report Waffle changes to Slack webhook

edx_arch_experiments/config_watcher/signals/receivers.py

@@ -4,23 +4,57 @@
 Call ``connect_receivers`` to initialize.
 """
 
+import html
+import json
 import logging
+import urllib.request
 
 import waffle.models
+from django.conf import settings
 from django.db.models import signals
 from django.dispatch import receiver
 
 log = logging.getLogger(__name__)
 
+# .. setting_name: CONFIG_WATCHER_SLACK_WEBHOOK_URL
+# .. setting_default: None
+# .. setting_description: Slack webhook URL to send config change events to.
+#   If not configured, this functionality is disabled.
+CONFIG_WATCHER_SLACK_WEBHOOK_URL = getattr(settings, 'CONFIG_WATCHER_SLACK_WEBHOOK_URL', None)
+
+
+def _send_to_slack(message):
+    """Send this message as plain text to the configured Slack channel."""
+    if not CONFIG_WATCHER_SLACK_WEBHOOK_URL:
+        return
+
+    # https://api.slack.com/reference/surfaces/formatting
+    body_data = {
+        'text': html.escape(message, quote=False)
+    }
+
+    req = urllib.request.Request(
+        url=CONFIG_WATCHER_SLACK_WEBHOOK_URL, data=json.dumps(body_data).encode(),
+        headers={"Content-Type": "application/json"},
+    )
+    with urllib.request.urlopen(req, timeout=2) as resp:
+        status = resp.getcode()
+        if status != 200:
+            log.error(f"Slack rejected the config watcher message. {status=}, body={resp.read().decode('utf-8')}")
+
+def _report_config_change(message):
+    log.info(message)
+    _send_to_slack(message)
+
 
 def _report_waffle_change(model_short_name, instance, created, fields):
     verb = "created" if created else "updated"
     state_desc = ", ".join(f"{field}={repr(getattr(instance, field))}" for field in fields)
-    log.info(f"Waffle {model_short_name} {instance.name!r} was {verb}. New config: {state_desc}")
+    _report_config_change(f"Waffle {model_short_name} {instance.name!r} was {verb}. New config: {state_desc}")
 
 
 def _report_waffle_delete(model_short_name, instance):
-    log.info(f"Waffle {model_short_name} {instance.name!r} was deleted")
+    _report_config_change(f"Waffle {model_short_name} {instance.name!r} was deleted")
 
 
 _WAFFLE_MODELS_TO_OBSERVE = [