FEATURE: on initial boot hint users on how to get admin

app/models/user.rb

@@ -67,6 +67,7 @@ class User < ActiveRecord::Base
   after_initialize :set_default_external_links_in_new_tab
 
   after_save :update_tracked_topics
+  after_save :clear_global_notice_if_needed
 
   after_create :create_email_token
   after_create :create_user_stat
@@ -586,6 +587,13 @@ class User < ActiveRecord::Base
     TrackedTopicsUpdater.new(id, auto_track_topics_after_msecs).call
   end
 
+  def clear_global_notice_if_needed
+    if admin && SiteSetting.has_login_hint
+      SiteSetting.has_login_hint = false
+      SiteSetting.global_notice = ""
+    end
+  end
+
   def create_user_stat
     stat = UserStat.new(new_since: Time.now)
     stat.user_id = id

config/environments/development.rb

@@ -45,5 +45,9 @@ Discourse::Application.configure do
 
   config.enable_anon_caching = false
   require 'rbtrace'
+
+  if emails = GlobalSetting.developer_emails
+    config.developer_emails = emails.split(",")
+  end
 end
 

config/initializers/06-ensure_login_hint.rb

@@ -0,0 +1,20 @@
+# Some sanity checking so we don't count on an unindexed column on boot
+if User.limit(20).count < 20 && User.where(admin: true).count == 1
+  notice =
+    if GlobalSetting.developer_emails.blank?
+      "No developer email addresses defined, logging in <a href='https://meta.discourse.org/t/how-to-create-an-administrator-account-after-install/14046'>will be tricky.</a>"
+    else
+      emails = GlobalSetting.developer_emails.split(",")
+      if emails.length > 1
+        emails = emails[0..-2].join(' , ') << " or #{emails[-1]} "
+      end
+      "Please create an account or login with #{emails}"
+    end
+
+  if notice != SiteSetting.global_notice
+    SiteSetting.global_notice = notice
+    SiteSetting.has_login_hint = true
+  end
+
+# we may be booting with no User table eg: first migration, just skip
+end rescue nil

config/site_settings.yml

@@ -479,6 +479,9 @@ uncategorized:
   global_notice:
     default: ""
     client: true
+  has_login_hint:
+    default: false
+    hidden: true
 
   # Category IDs
   lounge_category_id:

lib/auth/default_current_user_provider.rb

@@ -78,7 +78,8 @@ class Auth::DefaultCurrentUserProvider
         !user.admin &&
         Rails.configuration.respond_to?(:developer_emails) &&
         Rails.configuration.developer_emails.include?(user.email)
-      user.update_column(:admin, true)
+      user.admin = true
+      user.save
     end
   end