Factor GITLAB_SHELL_VERSION get method

lib/gitlab/backend/shell.rb

@@ -8,6 +8,13 @@ module Gitlab
       end
     end
 
+    class << self
+      def version_required
+        @version_required ||= File.read(Rails.root.
+                                        join('GITLAB_SHELL_VERSION')).strip
+      end
+    end
+
     # Init new repository
     #
     # name - project path with namespace

lib/tasks/gitlab/check.rake

@@ -574,20 +574,16 @@ namespace :gitlab do
       Gitlab::Shell.new.version
     end
 
-    def required_gitlab_shell_version
-      File.read(File.join(Rails.root, "GITLAB_SHELL_VERSION")).strip
-    end
-
     def gitlab_shell_major_version
-      required_gitlab_shell_version.split(".")[0].to_i
+      Gitlab::Shell.version_required.split('.')[0].to_i
     end
 
     def gitlab_shell_minor_version
-      required_gitlab_shell_version.split(".")[1].to_i
+      Gitlab::Shell.version_required.split('.')[1].to_i
     end
 
     def gitlab_shell_patch_version
-      required_gitlab_shell_version.split(".")[2].to_i
+      Gitlab::Shell.version_required.split('.')[2].to_i
     end
 
     def has_gitlab_shell3?

lib/tasks/gitlab/shell.rake

@@ -4,7 +4,7 @@ namespace :gitlab do
     task :install, [:tag, :repo] => :environment do |t, args|
       warn_user_is_not_gitlab
 
-      default_version = File.read(File.join(Rails.root, "GITLAB_SHELL_VERSION")).strip
+      default_version = Gitlab::Shell.version_required
       args.with_defaults(tag: 'v' + default_version, repo: "https://gitlab.com/gitlab-org/gitlab-shell.git")
 
       user = Gitlab.config.gitlab.user