Debian/Ubuntu:
apt install --no-install-recommends sssd-tools libnss-sss libpam-sss
[sssd] services = nss,pam config_file_version = 2 domains = LOCAL [domain/LOCAL] id_provider = local
chmod 600 /etc/sssd/sssd.conf
sssctl config-check service sssd restart
sss_useradd testuser1 sss_useradd testuser2
sss_groupadd testgroup1 sss_groupadd testgroup2 sss_usermod -a testgroup1 testuser1 sss_usermod -a testgroup2 testuser2
sss_groupshow testgroup1 sss_groupshow testgroup2 getent group testgroup1 getent group testgroup2 sss_groupmod -a testgroup2 testgroup1
sss_groupshow testgroup1 sss_groupshow testgroup2 getent group testgroup1 getent group testgroup2