From 4.1 to 4.2

1. Stop server & resque

sudo service gitlab stop

2. Update code & db

# Get latest code
sudo -u gitlab git fetch

sudo -u gitlab git checkout 4-2-stable

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

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

3. Start all

sudo service gitlab start