Fix Error 500 when visiting build page of project with nil runners_token

Properly ensure that the token exists and add defensively check for a
non-nil value.

Closes #4294

2 files changed, 7 insertions, 5 deletions

diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index 30f79fd3bfa..a4779d06de8 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -206,7 +206,7 @@ module Ci
 
     def trace
       trace = raw_trace
-      if project && trace.present?
+      if project && trace.present? && project.runners_token.present?
         trace.gsub(project.runners_token, 'xxxxxx')
       else
         trace
diff --git a/app/models/project.rb b/app/models/project.rb
index 7626c698816..0d7341e1384 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -50,6 +50,7 @@ class Project < ActiveRecord::Base
   include Sortable
   include AfterCommitQueue
   include CaseSensitivity
+  include TokenAuthenticatable
 
   extend Gitlab::ConfigHelper
 
@@ -193,10 +194,7 @@ class Project < ActiveRecord::Base
     if: ->(project) { project.avatar.present? && project.avatar_changed? }
   validates :avatar, file_size: { maximum: 200.kilobytes.to_i }
 
-  before_validation :set_runners_token_token
-  def set_runners_token_token
-    self.runners_token = SecureRandom.hex(15) if self.runners_token.blank?
-  end
+  add_authentication_token_field :runners_token
 
   mount_uploader :avatar, AvatarUploader
 
@@ -900,4 +898,8 @@ class Project < ActiveRecord::Base
     return true unless forked?
     Gitlab::VisibilityLevel.allowed_fork_levels(forked_from_project.visibility_level).include?(level.to_i)
   end
+
+  def runners_token
+    ensure_runners_token!
+  end
 end