adduser(8) --disabled-password --quiet --system --home /var/run/rails-new --no-create-home --gecos "Rails New daemon" --group rails-new
add a user or group to the system
       Like --disabled-login, but logins are still possible (for example using  SSH  RSA  keys)  but  not
       using password authentication.
       Suppress informational messages, only show warnings and errors.
       Create a system user or group.
--home DIR
       Use DIR as the user's home directory, rather than the default specified by the configuration file.
       If the directory does not exist, it is created and skeleton files are copied.
       Do not create the home directory, even if it doesn't exist.
--gecos GECOS
       Set  the  gecos field for the new entry generated.  adduser will not ask for finger information if
       this option is given.
       When  combined with --system, a group with the same name and ID as the system user is created.  If
       not combined with --system, a group with the given name is created.  This is the default action if
       the program is invoked as addgroup.
source manpages: adduser