Use system paths for appearance logos

When object storage is enabled, the logos used to customize a GitLab
appearance causes the time-limited URLs to be used. We fix this
by forcing all of these URLs to use the /uploads/-/system prefix
so that they will always be proxied through GitLab.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/6778

3 files changed, 31 insertions, 3 deletions

diff --git a/app/helpers/appearances_helper.rb b/app/helpers/appearances_helper.rb
index 3f69af50f25..473c90c882c 100644
--- a/app/helpers/appearances_helper.rb
+++ b/app/helpers/appearances_helper.rb
@@ -11,7 +11,7 @@ module AppearancesHelper
   end
 
   def brand_image
-    image_tag(current_appearance.logo) if current_appearance&.logo?
+    image_tag(current_appearance.logo_path) if current_appearance&.logo?
   end
 
   def brand_text
@@ -28,7 +28,7 @@ module AppearancesHelper
 
   def brand_header_logo
     if current_appearance&.header_logo?
-      image_tag current_appearance.header_logo
+      image_tag current_appearance.header_logo_path
     else
       render 'shared/logo.svg'
     end
diff --git a/app/helpers/emails_helper.rb b/app/helpers/emails_helper.rb
index e4c46ceeaa2..fa5d3ae474a 100644
--- a/app/helpers/emails_helper.rb
+++ b/app/helpers/emails_helper.rb
@@ -58,7 +58,7 @@ module EmailsHelper
   def header_logo
     if current_appearance&.header_logo?
       image_tag(
-        current_appearance.header_logo,
+        current_appearance.header_logo_path,
         style: 'height: 50px'
       )
     else
diff --git a/app/models/appearance.rb b/app/models/appearance.rb
index bffba3e13fa..e114c435b67 100644
--- a/app/models/appearance.rb
+++ b/app/models/appearance.rb
@@ -28,4 +28,32 @@ class Appearance < ActiveRecord::Base
       errors.add(:single_appearance_row, 'Only 1 appearances row can exist')
     end
   end
+
+  def logo_path
+    logo_system_path(logo, 'logo')
+  end
+
+  def header_logo_path
+    logo_system_path(header_logo, 'header_logo')
+  end
+
+  def favicon_path
+    logo_system_path(favicon, 'favicon')
+  end
+
+  private
+
+  def logo_system_path(logo, mount_type)
+    return unless logo&.upload
+
+    # If we're using a CDN, we need to use the full URL
+    asset_host = ActionController::Base.asset_host
+    local_path = Gitlab::Routing.url_helpers.appearance_upload_path(
+      filename: logo.filename,
+      id: logo.upload.model_id,
+      model: 'appearance',
+      mounted_as: mount_type)
+
+    Gitlab::Utils.append_path(asset_host, local_path)
+  end
 end