From 2d2f9e51594e33f04bfda4012e3d4c7e48539fe3 Mon Sep 17 00:00:00 2001
From: Grzegorz Bizon <grzesiek.bizon@gmail.com>
Date: Sat, 6 Jan 2018 14:44:43 +0100
Subject: [PATCH] Do not attempt to migrate legacy pipeline stages

---
 .../migrate_build_stage.rb                    | 33 ++++++++++++-------
 .../migrate_build_stage_spec.rb               |  5 ++-
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/lib/gitlab/background_migration/migrate_build_stage.rb b/lib/gitlab/background_migration/migrate_build_stage.rb
index a870609e68d..7139ac03737 100644
--- a/lib/gitlab/background_migration/migrate_build_stage.rb
+++ b/lib/gitlab/background_migration/migrate_build_stage.rb
@@ -6,9 +6,9 @@ module Gitlab
   module BackgroundMigration
     class MigrateBuildStage
       def perform(id)
-        Ci::Build.find_by(id: id).try do |build|
-          Stage.new(build).tap do |stage|
-            break if stage.exists?
+        DatabaseBuild.find_by(id: id).try do |build|
+          MigratableStage.new(build).tap do |stage|
+            break if stage.exists? || stage.legacy?
 
             stage.ensure!
             stage.migrate_reference!
@@ -17,15 +17,15 @@ module Gitlab
         end
       end
 
-      class Ci::Stage < ActiveRecord::Base
+      class DatabaseStage < ActiveRecord::Base
         self.table_name = 'ci_stages'
       end
 
-      class Ci::Build < ActiveRecord::Base
+      class DatabaseBuild < ActiveRecord::Base
         self.table_name = 'ci_builds'
       end
 
-      class Stage
+      class MigratableStage
         def initialize(build)
           @build = build
         end
@@ -34,20 +34,29 @@ module Gitlab
           @build.reload.stage_id.present?
         end
 
+        ##
+        # We can have some very old stages that do not have `ci_builds.stage` set.
+        #
+        # In that case we just don't migrate such stage.
+        #
+        def legacy?
+         @build.stage.nil?
+        end
+
         def ensure!
           find || create!
         end
 
         def find
-          Ci::Stage.find_by(name: @build.stage,
-                            pipeline_id: @build.commit_id,
-                            project_id: @build.project_id)
+          DatabaseStage.find_by(name: @build.stage,
+                                pipeline_id: @build.commit_id,
+                                project_id: @build.project_id)
         end
 
         def create!
-          Ci::Stage.create!(name: @build.stage,
-                            pipeline_id: @build.commit_id,
-                            project_id: @build.project_id)
+          DatabaseStage.create!(name: @build.stage,
+                                pipeline_id: @build.commit_id,
+                                project_id: @build.project_id)
         end
 
         def migrate_reference!
diff --git a/spec/lib/gitlab/background_migration/migrate_build_stage_spec.rb b/spec/lib/gitlab/background_migration/migrate_build_stage_spec.rb
index b675db463af..d20b5c29a71 100644
--- a/spec/lib/gitlab/background_migration/migrate_build_stage_spec.rb
+++ b/spec/lib/gitlab/background_migration/migrate_build_stage_spec.rb
@@ -29,6 +29,8 @@ describe Gitlab::BackgroundMigration::MigrateBuildStage, :migration, schema: 201
                  stage_idx: 1, stage: 'test', status: :success)
     jobs.create!(id: 5, commit_id: 1, project_id: 123,
                  stage_idx: 3, stage: 'deploy', status: :pending)
+    jobs.create!(id: 6, commit_id: 1, project_id: 123,
+                 stage_idx: 3, stage: nil, status: :pending)
   end
 
   it 'correctly migrates builds stages' do
@@ -40,7 +42,8 @@ describe Gitlab::BackgroundMigration::MigrateBuildStage, :migration, schema: 201
 
     expect(stages.count).to eq 3
     expect(stages.all.pluck(:name)).to match_array %w[test build deploy]
-    expect(jobs.where(stage_id: nil)).to be_empty
+    expect(jobs.where(stage_id: nil)).to be_one
+    expect(jobs.find_by(stage_id: nil).id).to eq 6
     expect(stages.all.pluck(:status)).to match_array [STATUSES[:success],
                                                       STATUSES[:failed],
                                                       STATUSES[:pending]]