in files/gitlab-cookbooks/gitlab/libraries/gitlab_workhorse.rb [141:151]
def parse_redis_master_settings
Gitlab['gitlab_workhorse']['redis_sentinel_master'] ||= Gitlab['redis']['master_name'] || Gitlab[:node]['redis']['master_name']
Gitlab['gitlab_workhorse']['redis_sentinel_master_ip'] ||= Gitlab['redis']['master_ip'] || Gitlab[:node]['redis']['master_ip']
Gitlab['gitlab_workhorse']['redis_sentinel_master_port'] ||= Gitlab['redis']['master_port'] || Gitlab[:node]['redis']['master_port']
Gitlab['gitlab_workhorse']['redis_password'] ||= Gitlab['redis']['master_password'] || Gitlab[:node]['redis']['master_password']
end