Include forum status in LMS heartbeat service.

lms/lib/comment_client/utils.py

@@ -8,6 +8,7 @@ import requests
 from django.utils.translation import get_language
 
 import dogstats_wrapper as dog_stats_api
+from .settings import SERVICE_HOST as COMMENTS_SERVICE
 
 log = logging.getLogger(__name__)
 
@@ -171,3 +172,30 @@ class CommentClientPaginatedResult(object):
         self.num_pages = num_pages
         self.thread_count = thread_count
         self.corrected_text = corrected_text
+
+
+def check_forum_heartbeat():
+    """
+    Check the forum connection via its built-in heartbeat service and create an answer which can be used in the LMS
+    heartbeat django application.
+    This function can be connected to the LMS heartbeat checker through the HEARTBEAT_CHECKS variable.
+    """
+    # To avoid dependency conflict
+    from django_comment_common.models import ForumsConfig
+    config = ForumsConfig.current()
+
+    if not config.enabled:
+        # If this check is enabled but forums disabled, don't connect, just report no error
+        return 'forum', True, 'OK'
+
+    try:
+        res = requests.get(
+            '%s/heartbeat' % COMMENTS_SERVICE,
+            timeout=config.connection_timeout
+        ).json()
+        if res['OK']:
+            return 'forum', True, 'OK'
+        else:
+            return 'forum', False, res.get('check', 'Forum heartbeat failed')
+    except Exception as fail:
+        return 'forum', False, unicode(fail)