1 files changed, 128 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/fix_pages_access_level.rb b/lib/gitlab/background_migration/fix_pages_access_level.rb
new file mode 100644
index 00000000000..0d49f3dd8c5
--- /dev/null
+++ b/lib/gitlab/background_migration/fix_pages_access_level.rb
@@ -0,0 +1,128 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # corrects stored pages access level on db depending on project visibility
+    class FixPagesAccessLevel
+      # Copy routable here to avoid relying on application logic
+      module Routable
+        def build_full_path
+          if parent && path
+            parent.build_full_path + '/' + path
+          else
+            path
+          end
+        end
+      end
+
+      # Namespace
+      class Namespace < ApplicationRecord
+        self.table_name = 'namespaces'
+        self.inheritance_column = :_type_disabled
+
+        include Routable
+
+        belongs_to :parent, class_name: "Namespace"
+      end
+
+      # Project
+      class Project < ActiveRecord::Base
+        self.table_name = 'projects'
+        self.inheritance_column = :_type_disabled
+
+        include Routable
+
+        belongs_to :namespace
+        alias_method :parent, :namespace
+        alias_attribute :parent_id, :namespace_id
+
+        PRIVATE = 0
+        INTERNAL = 10
+        PUBLIC = 20
+
+        def pages_deployed?
+          Dir.exist?(public_pages_path)
+        end
+
+        def public_pages_path
+          File.join(pages_path, 'public')
+        end
+
+        def pages_path
+          # TODO: when we migrate Pages to work with new storage types, change here to use disk_path
+          File.join(Settings.pages.path, build_full_path)
+        end
+      end
+
+      # ProjectFeature
+      class ProjectFeature < ActiveRecord::Base
+        include ::EachBatch
+
+        self.table_name = 'project_features'
+
+        belongs_to :project
+
+        PRIVATE = 10
+        ENABLED = 20
+        PUBLIC  = 30
+      end
+
+      def perform(start_id, stop_id)
+        fix_public_access_level(start_id, stop_id)
+
+        make_internal_projects_public(start_id, stop_id)
+
+        fix_private_access_level(start_id, stop_id)
+      end
+
+      private
+
+      def access_control_is_enabled
+        @access_control_is_enabled = Gitlab.config.pages.access_control
+      end
+
+      # Public projects are allowed to have only enabled pages_access_level
+      # which is equivalent to public
+      def fix_public_access_level(start_id, stop_id)
+        project_features(start_id, stop_id, ProjectFeature::PUBLIC, Project::PUBLIC).each_batch do |features|
+          features.update_all(pages_access_level: ProjectFeature::ENABLED)
+        end
+      end
+
+      # If access control is disabled and project has pages deployed
+      # project will become unavailable when access control will become enabled
+      # we make these projects public to avoid negative surprise to user
+      def make_internal_projects_public(start_id, stop_id)
+        return if access_control_is_enabled
+
+        project_features(start_id, stop_id, ProjectFeature::ENABLED, Project::INTERNAL).find_each do |project_feature|
+          next unless project_feature.project.pages_deployed?
+
+          project_feature.update(pages_access_level: ProjectFeature::PUBLIC)
+        end
+      end
+
+      # Private projects are not allowed to have enabled access level, only `private` and `public`
+      # If access control is enabled, these projects currently behave as if the have `private` pages_access_level
+      # if access control is disabled, these projects currently behave as if the have `public` pages_access_level
+      # so we preserve this behaviour for projects with pages already deployed
+      # for project without pages we always set `private` access_level
+      def fix_private_access_level(start_id, stop_id)
+        project_features(start_id, stop_id, ProjectFeature::ENABLED, Project::PRIVATE).find_each do |project_feature|
+          if access_control_is_enabled
+            project_feature.update!(pages_access_level: ProjectFeature::PRIVATE)
+          else
+            fixed_access_level = project_feature.project.pages_deployed? ? ProjectFeature::PUBLIC : ProjectFeature::PRIVATE
+            project_feature.update!(pages_access_level: fixed_access_level)
+          end
+        end
+      end
+
+      def project_features(start_id, stop_id, pages_access_level, project_visibility_level)
+        ProjectFeature.where(id: start_id..stop_id).joins(:project)
+          .where(pages_access_level: pages_access_level)
+          .where(projects: { visibility_level: project_visibility_level })
+      end
+    end
+  end
+end