Merge branch 'sh-bump-ruby-2.5.3-ee' into 'master'

Upgrade to Ruby 2.5.3 (EE port)

Closes gitlab-ce#41825

See merge request gitlab-org/gitlab-ee!8069

.gitlab-ci.yml

-image: "dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.4.5-golang-1.9-git-2.18-chrome-69.0-node-10.x-yarn-1.12-postgresql-9.6-graphicsmagick-1.3.29"
+image: "dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.5.3-golang-1.9-git-2.18-chrome-69.0-node-10.x-yarn-1.12-postgresql-9.6-graphicsmagick-1.3.29"
 
 .dedicated-runner: &dedicated-runner
   retry: 1
@@ -6,7 +6,7 @@ image: "dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.4.5-golang-1.9-git
     - gitlab-org
 
 .default-cache: &default-cache
-  key: "debian-stretch-ruby-2.4.5-node-10.x"
+  key: "debian-stretch-ruby-2.5.3-node-10.x"
   paths:
     - vendor/ruby
     - .yarn-cache/
@@ -152,7 +152,7 @@ stages:
   <<: *except-docs-and-qa
 
 .single-script-job: &single-script-job
-  image: ruby:2.4-alpine
+  image: ruby:2.5-alpine
   stage: test
   cache: {}
   dependencies: []
@@ -316,6 +316,8 @@ stages:
   script:
     - git fetch https://gitlab.com/gitlab-org/gitlab-ee.git v9.3.0-ee
     - git checkout -f FETCH_HEAD
+    - sed -i "s/gem 'oj', '~> 2.17.4'//" Gemfile
+    - bundle update google-protobuf grpc
     - bundle install $BUNDLE_INSTALL_FLAGS
     - date
     - cp config/gitlab.yml.example config/gitlab.yml
@@ -423,7 +425,7 @@ review-docs-cleanup:
 # Trigger a docker image build in CNG (Cloud Native GitLab) repository
 #
 cloud-native-image:
-  image: ruby:2.4-alpine
+  image: ruby:2.5-alpine
   before_script: []
   dependencies: []
   stage: test
@@ -506,7 +508,7 @@ update-tests-metadata:
 
 flaky-examples-check:
   <<: *dedicated-runner
-  image: ruby:2.4-alpine
+  image: ruby:2.5-alpine
   services: []
   before_script: []
   variables:
@@ -754,7 +756,7 @@ static-analysis:
   script:
     - scripts/static-analysis
   cache:
-    key: "debian-stretch-ruby-2.4.5-node-10.x-and-rubocop"
+    key: "debian-stretch-ruby-2.5.3-node-10.x-and-rubocop"
     paths:
       - vendor/ruby
       - .yarn-cache/
@@ -878,7 +880,7 @@ gitlab:setup-mysql:
 # Frontend-related jobs
 gitlab:assets:compile:
   <<: *dedicated-no-docs-and-no-qa-pull-cache-job
-  image: dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.4.4-git-2.18-chrome-69.0-node-8.x-yarn-1.2-graphicsmagick-1.3.29-docker-18.06.1
+  image: dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.5.3-git-2.18-chrome-69.0-node-8.x-yarn-1.2-graphicsmagick-1.3.29-docker-18.06.1
   dependencies: []
   services:
     - docker:stable-dind

.ruby-version

-2.4.5
+2.5.3