FIX: Switch discobot to pull avatar from gravatar.

app/models/user_avatar.rb

@@ -5,6 +5,14 @@ class UserAvatar < ActiveRecord::Base
   belongs_to :gravatar_upload, class_name: 'Upload'
   belongs_to :custom_upload, class_name: 'Upload'
 
+  @@custom_user_gravatar_email_hash = {
+    Discourse::SYSTEM_USER_ID => User.email_hash("info@discourse.org")
+  }
+
+  def self.register_custom_user_gravatar_email_hash(user_id, email)
+    @@custom_user_gravatar_email_hash[user_id] = User.email_hash(email)
+  end
+
   def contains_upload?(id)
     gravatar_upload_id == id || custom_upload_id == id
   end
@@ -12,14 +20,14 @@ class UserAvatar < ActiveRecord::Base
   def update_gravatar!
     DistributedMutex.synchronize("update_gravatar_#{user_id}") do
       begin
-        self.update!(last_gravatar_download_attempt: Time.now)
+        self.update!(last_gravatar_download_attempt: Time.zone.now)
 
         max = Discourse.avatar_sizes.max
 
         # The user could be deleted before this executes
         return if user.blank? || user.primary_email.blank?
 
-        email_hash = user_id == Discourse::SYSTEM_USER_ID ? User.email_hash("info@discourse.org") : user.email_hash
+        email_hash = @@custom_user_gravatar_email_hash[user_id] || user.email_hash
         gravatar_url = "https://#{SiteSetting.gravatar_base_url}/avatar/#{email_hash}.png?s=#{max}&d=404&reset_cache=#{SecureRandom.urlsafe_base64(5)}"
 
         # follow redirects in case gravatar change rules on us

plugins/discourse-narrative-bot/db/fixtures/001_discobot.rb

@@ -4,20 +4,20 @@ discobot_username = 'discobot'
 
 def seed_primary_email
   UserEmail.seed do |ue|
-    ue.id = -2
+    ue.id = DiscourseNarrativeBot::BOT_USER_ID
     ue.email = "discobot_email"
     ue.primary = true
-    ue.user_id = -2
+    ue.user_id = DiscourseNarrativeBot::BOT_USER_ID
   end
 end
 
-unless user = User.find_by(id: -2)
+unless user = User.find_by(id: DiscourseNarrativeBot::BOT_USER_ID)
   suggested_username = UserNameSuggester.suggest(discobot_username)
 
   seed_primary_email
 
   User.seed do |u|
-    u.id = -2
+    u.id = DiscourseNarrativeBot::BOT_USER_ID
     u.name = discobot_username
     u.username = suggested_username
     u.username_lower = suggested_username.downcase
@@ -32,7 +32,7 @@ unless user = User.find_by(id: -2)
     begin
       UserAvatar.import_url_for_user(
         "https://cdn.discourse.org/dev/uploads/default/original/2X/e/edb63d57a720838a7ce6a68f02ba4618787f2299.png",
-        User.find(-2),
+        User.find(DiscourseNarrativeBot::BOT_USER_ID),
         override_gravatar: true
       )
     rescue
@@ -41,7 +41,7 @@ unless user = User.find_by(id: -2)
   end
 end
 
-bot = User.find(-2)
+bot = User.find(DiscourseNarrativeBot::BOT_USER_ID)
 
 # ensure discobot has a primary email
 unless bot.primary_email
@@ -62,4 +62,4 @@ if !bot.user_profile.bio_raw
   )
 end
 
-Group.user_trust_level_change!(-2, TrustLevel[4])
+Group.user_trust_level_change!(DiscourseNarrativeBot::BOT_USER_ID, TrustLevel[4])

plugins/discourse-narrative-bot/db/post_migrate/20200520015508_clear_last_gravatar_download_attempt_on_user_avatars.rb

@@ -0,0 +1,12 @@
+class ClearLastGravatarDownloadAttemptOnUserAvatars < ActiveRecord::Migration[6.0]
+  def up
+    execute <<~SQL
+      UPDATE user_avatars
+      SET last_gravatar_download_attempt = null
+      WHERE user_id = -2 AND custom_upload_id IS NULL AND gravatar_upload_id IS NULL
+    SQL
+  end
+
+  def down
+  end
+end

plugins/discourse-narrative-bot/plugin.rb

@@ -55,6 +55,7 @@ after_initialize do
 
   module ::DiscourseNarrativeBot
     PLUGIN_NAME = "discourse-narrative-bot".freeze
+    BOT_USER_ID = -2
 
     class Engine < ::Rails::Engine
       engine_name PLUGIN_NAME
@@ -271,4 +272,9 @@ after_initialize do
       end
     end
   end
+
+  UserAvatar.register_custom_user_gravatar_email_hash(
+    DiscourseNarrativeBot::BOT_USER_ID,
+    "discobot@discourse.org"
+  )
 end