FEATURE: notify admins if problems have been reported on the dashboard for a while

app/jobs/scheduled/dashboard_stats.rb

@@ -5,6 +5,13 @@ module Jobs
     every 30.minutes
 
     def execute(args)
+      problems_started_at = AdminDashboardData.problems_started_at
+      if problems_started_at && problems_started_at < 2.days.ago
+        # If there have been problems reported on the dashboard for a while,
+        # send a message to admins no more often than once per week.
+        GroupMessage.create(Group[:admins].name, :dashboard_problems, {limit_once_per: 7.days.to_i})
+      end
+
       stats = AdminDashboardData.fetch_stats
       set_cache(AdminDashboardData, stats)
       stats

app/models/admin_dashboard_data.rb

@@ -50,7 +50,33 @@ class AdminDashboardData
     AdminDashboardData.problem_messages.each do |i18n_key|
       problems << AdminDashboardData.problem_message_check(i18n_key)
     end
-    problems.compact
+    problems.compact!
+
+    if problems.empty?
+      self.class.clear_problems_started
+    else
+      self.class.set_problems_started
+    end
+
+    problems
+  end
+
+  def self.problems_started_key
+    "dash-problems-started-at"
+  end
+
+  def self.set_problems_started
+    existing_time = $redis.get(problems_started_key)
+    $redis.setex(problems_started_key, 14.days.to_i, existing_time || Time.zone.now.to_s)
+  end
+
+  def self.clear_problems_started
+    $redis.del problems_started_key
+  end
+
+  def self.problems_started_at
+    s = $redis.get(problems_started_key)
+    s ? Time.zone.parse(s) : nil
   end
 
   # used for testing

config/locales/server.en.yml

@@ -2044,6 +2044,13 @@ en:
       subject_template: "Downloading remote images disabled"
       text_body_template: "The `download_remote_images_to_local` setting was disabled because the disk space limit at `download_remote_images_threshold` was reached."
 
+    dashboard_problems:
+      subject_template: "Problems have been found"
+      text_body_template: |
+        Some problems are being reported on your admin dashboard.
+
+        [Please review and fix them](%{base_url}/admin).
+
   unsubscribe_link: |
     To stop receiving notifications for this particular topic, [click here](%{unsubscribe_url}). To unsubscribe from these emails, change your [user preferences](%{user_preferences_url})