From 2.6.x to 2.9.0

1. Stop server & resque

2. Update code & db

# Get latest code
sudo -u gitlab git pull origin stable

# Install libs
sudo -u gitlab bundle install --without development test

# update db
sudo -u gitlab bundle exec rake db:migrate RAILS_ENV=production

# !!! Config should be replaced with a new one. Check it after replace
cp config/gitlab.yml.example config/gitlab.yml

# update gitolite hooks
sudo cp ./lib/hooks/post-receive /home/git/share/gitolite/hooks/common/post-receive
sudo chown git:git /home/git/share/gitolite/hooks/common/post-receive

# Check app status
sudo -u gitlab bundle exec rake gitlab:app:status RAILS_ENV=production

3. Start web server & Resque