Chef-server.rb file for chef install

I want to install chef with specific user and group and custom log paths so specifying everything in chef-server.rb file.For user option, I specified the following:
user[‘home’]= "/home/developer"
user[‘shell’] = "/bin/bash"
user[‘username’] = 'chef’
chef is configuring everything with chef user and chef group.I want the group to be developer instead of chef. Is there a way to specify group as well or I have to change the group explicitly post installation.