Merge branch 'dont-drop-stuck-builds' into 'master'

Don't fail builds for projects that are deleted when they are stuck

## What does this MR do?

Solves when dropping stuck connection.
```
Dropping stuck pending build 1545510 for runner 
NoMethodError: undefined method `origin_merge_requests' for nil:NilClass
    from /opt/gitlab/embedded/service/gitlab-rails/app/services/merge_requests/base_service.rb:50:in `merge_request_from'
    from /opt/gitlab/embedded/service/gitlab-rails/app/services/merge_requests/base_service.rb:57:in `each_merge_request'
    from /opt/gitlab/embedded/service/gitlab-rails/app/services/merge_requests/add_todo_when_build_fails_service.rb:5:in `execute'
    from /opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/metrics/instrumentation.rb:164:in `execute'
    from /opt/gitlab/embedded/service/gitlab-rails/app/models/commit_status.rb:51:in `block (2 levels) in <class:CommitStatus>'
    from /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/state_machines-0.4.0/lib/state_machines/eval_helpers.rb:79:in `call'
...
```

This happens, because that `default_scope` of `Projects` filters returns the projects that are not deleted, where `Ci::Build` doesn't take into account.


See merge request !4609

CHANGELOG

@@ -27,6 +27,7 @@ v 8.9.0 (unreleased)
   - Redesign navigation for project pages
   - Fix groups API to list only user's accessible projects
   - Redesign account and email confirmation emails
+  - Don't fail builds for projects that are deleted
   - `git clone https://host/namespace/project` now works, in addition to using the `.git` suffix
   - Bump nokogiri to 1.6.8
   - Use gitlab-shell v3.0.0

app/workers/stuck_ci_builds_worker.rb

@@ -6,7 +6,7 @@ class StuckCiBuildsWorker
   def perform
     Rails.logger.info 'Cleaning stuck builds'
 
-    builds = Ci::Build.running_or_pending.where('updated_at < ?', BUILD_STUCK_TIMEOUT.ago)
+    builds = Ci::Build.joins(:project).running_or_pending.where('ci_builds.updated_at < ?', BUILD_STUCK_TIMEOUT.ago)
     builds.find_each(batch_size: 50).each do |build|
       Rails.logger.debug "Dropping stuck #{build.status} build #{build.id} for runner #{build.runner_id}"
       build.drop

spec/workers/stuck_ci_builds_worker_spec.rb

@@ -2,6 +2,7 @@ require "spec_helper"
 
 describe StuckCiBuildsWorker do
   let!(:build) { create :ci_build }
+  let(:worker) { described_class.new }
 
   subject do
     build.reload
@@ -16,13 +17,13 @@ describe StuckCiBuildsWorker do
 
       it 'gets dropped if it was updated over 2 days ago' do
         build.update!(updated_at: 2.days.ago)
-        StuckCiBuildsWorker.new.perform
+        worker.perform
         is_expected.to eq('failed')
       end
 
       it "is still #{status}" do
         build.update!(updated_at: 1.minute.ago)
-        StuckCiBuildsWorker.new.perform
+        worker.perform
         is_expected.to eq(status)
       end
     end
@@ -36,9 +37,21 @@ describe StuckCiBuildsWorker do
 
       it "is still #{status}" do
         build.update!(updated_at: 2.days.ago)
-        StuckCiBuildsWorker.new.perform
+        worker.perform
         is_expected.to eq(status)
       end
     end
   end
+
+  context "for deleted project" do
+    before do
+      build.update!(status: :running, updated_at: 2.days.ago)
+      build.project.update(pending_delete: true)
+    end
+
+    it "does not drop build" do
+      expect_any_instance_of(Ci::Build).not_to receive(:drop)
+      worker.perform
+    end
+  end
 end