Add DB constraint ci_runners.runner_type not null

db/migrate/20180508135515_set_runner_type_not_null.rb

+class SetRunnerTypeNotNull < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    change_column_null(:ci_runners, :runner_type, false)
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180508055821) do
+ActiveRecord::Schema.define(version: 20180508135515) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -497,7 +497,7 @@ ActiveRecord::Schema.define(version: 20180508055821) do
     t.integer "access_level", default: 0, null: false
     t.string "ip_address"
     t.integer "maximum_timeout"
-    t.integer "runner_type", limit: 2
+    t.integer "runner_type", limit: 2, null: false
   end
 
   add_index "ci_runners", ["contacted_at"], name: "index_ci_runners_on_contacted_at", using: :btree

spec/factories/ci/runners.rb

@@ -6,6 +6,7 @@ FactoryBot.define do
     is_shared false
     active    true
     access_level :not_protected
+    runner_type :project_type
 
     trait :online do
       contacted_at Time.now
@@ -13,6 +14,7 @@ FactoryBot.define do
 
     trait :shared do
       is_shared true
+      runner_type :instance_type
     end
 
     trait :specific do