Samba AD on CentOS7
This page describe Samba4 Active Directory installation on CentOS. The environment is composed of 2 DCs with replication, and one fileserver.
dc1.domain.com.br dc2.domain.com.br fileserver.domain.com.br
The installation is based on CentOS7 Minimal ISO, you should update the system and install basic tools.
yum update yum install -y vim wget
This pre-setup can be done in all 3 servers, basically it will setup the Sernet Samba Repository and install samba from repo.
wget https://raw.githubusercontent.com/hflautert/lotus7/master/samba4/pre_install_samba4.sh chmod +x pre_install_samba4.sh ./pre_install_samba4.sh
First of all we need a domain, so lets provision it.
samba-tool domain provision --use-rfc2307 --interactive
Setup kerberos, you can use the same as dc1.
scp firstname.lastname@example.org:/etc/krb5.conf /etc/krb5.conf
Join as DC.
samba-tool domain join domain.com.br DC -Uadministrator --realm=domain.com.br
Fix DNS if it was not created automatically:
samba-tool dns add dc1 domain.com.br dc2 A <IP-OF-DC2> -Uadministrator
After couple minutes, we can see the replication:
samba-tool drs showrepl
- You can safely ignore it: Warning: No NC replicated for Connection!
This post setup will configure the services to startup and disable Selinux and Firewall, during my tests firewalld did not save the allowed ports, even with permanent flag, so I´v decided to disable to avoid problems.
wget https://raw.githubusercontent.com/hflautert/lotus7/master/samba4/post_install_samba4.sh chmod +x post_install_samba4.sh ./post_install_samba4.sh
The pre-setup is the same, but we are not going provision neither join, the fileserver will be just a member of domain. CentOS bring us a useful tool to do it, actually we are going to setup authentication and join the domain in one shot.
Prep, auth and join
Lets start testing our DNS:
host -t SRV _ldap._tcp.domain.com.br. _ldap._tcp.domain.com.br has SRV record 0 100 389 dc1.domain.com.br.
Setup auth and join the domain:
authconfig --enablewinbindusedefaultdomain --update
Se domain info and users:
net ads info wbinfo -u wbinfo -g
Grant rights to domain admins change disk permissions:
net rpc rights grant 'domain admins' SeDiskOperatorPrivilege -U'administrator' -I fileserver.domain.com.br
Here there is a TODO, you can map what you need to set on Selinux, or disable it:
setenforce 0 sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
Setup samba start mode
sed -i 's/SAMBA_START_MODE="none"/SAMBA_START_MODE="classic"/g' /etc/default/sernet-samba
Add followinf lines at end of [global] section on /etc/samba/smb.conf
vfs objects = acl_xattr map acl inherit = Yes store dos attributes = Yes
systemctl restart sernet-samba-smbd systemctl restart sernet-samba-nmbd systemctl restart sernet-samba-winbindd
chkconfig sernet-samba-nmbd on chkconfig sernet-samba-smbd on chkconfig sernet-samba-winbindd on
Add share on smb.conf
[share] path = /storage/share read only = no
systemctl reload sernet-samba-smbd
chmod -Rf 770 /storage/share chown administrator:"domain admins" /storage/share
Set ACL to domain admins can change permissions.
setfacl -m default:group:"domain admins":rwx /storage/share
All my troubles were related to:
- Check network-firewall.
- Check DNS.
- Check Time and Date.