Step by step,

yum install nscd samba samba-common samba-client samba-winbind

yum upgrade

vi /etc/hosts
192.168.1.30 dc.domain.com pdc01

Run authconfig-tui
Authentication Configuration – check Cache Information, Use Winbind, Use MD5 Passwords, Use Shadow Passwords, Use Winbind Authentication
Winbind Settings – check ads, type the short name of the domain, example.com needs to be just example in this field, enter FQDN of domain controllers, ADS realm is FQDN of primary DC, check /bin/bash
Click on Join Domain
Enter credentials for a domain administrator and make sure the server successfully joined the domain

vi /usr/local/bin/bash-wrapper

#!/bin/sh

# This script restricts shell access to privileged users. The “template shell”
# option in the ‘/etc/samba/smb.conf’ file should be set to call this wrapper.

# Get group memberships for this user.
BFN_ID=$(/usr/bin/id)

# Grant shell access to users that are in the local wheel group.
if /bin/echo “$BFN_ID” | /bin/grep -P ‘[=,][0-9]{1,8}(wheel)’ > /dev/null
then
exec /bin/bash –login “$@”
fi

# Grant shell access to users that are in the domain administrators group.
if /bin/echo “$BFN_ID” | /bin/grep -P ‘[=,][0-9]{1,8}(domain admins)’ > /dev/null
then
exec /bin/bash –login “$@”
fi

# Else print a notice and just exit.
echo “Shell access to this computer is disabled.”

# eof

vi /usr/local/bin/ad-phase2.sh

# ad-phase2.sh – Phase 2
# Description: This script automates the process of joining a linux box
# to an AD domain. The process is divided in two parts.
#
# Please edit the relevant parts of the script below prior running it

# This block doesn’t need to be edited
#sed -i ‘s%protocols: files%protocols: files winbind%g’ /etc/nsswitch.conf
#sed -i ‘s%rpc: files%rpc: files winbind%g’ /etc/nsswitch.conf
#sed -i ‘s%netgroup: files%netgroup: files winbind%g’ /etc/nsswitch.conf
#sed -i ‘s%automount: files%automount: files winbind%g’ /etc/nsswitch.conf

# The following line allows users to logon without the ugly EXAMPLEuser syntax
sed -i ‘s%winbind use default domain = false%winbind use default domain = true%g’ /etc/samba/smb.conf

# More parameters to make life easier with UID and GID correspondances
sed -i ‘s% template shell = /bin/bash% template shell = /usr/local/bin/bash-wrapper%g’ /etc/samba/smb.conf
sed -i ‘/ winbind offline logon = false/a winbind enum users = true’ /etc/samba/smb.conf
sed -i ‘/winbind enum users = true/a winbind enum groups = true’ /etc/samba/smb.conf
sed -i ‘/winbind enum groups = true/a winbind cache time = 5’ /etc/samba/smb.conf
sed -i ‘/winbind cache time = 5/a winbind nested groups = true’ /etc/samba/smb.conf

# This line will allow for home folders to be created in /home/DOMAIN/username upon first login
echo “session optional pam_mkhomedir.so skel=/etc/skel/ umask=0022” >> /etc/pam.d/system-auth

# The following line will allow all the users within the Domain Admins group to sudo on the server
echo “%domain admins ALL=(ALL) ALL” >> /etc/sudoers

# Replace “base OU=Users,DC=example,DC=com” with the container of the users you want to allow on the box
sed -i ‘s%base dc=*******,dc=com%base OU=Users,DC=*******************,DC=com%g’ /etc/openldap/ldap.conf
chmod +x /usr/local/bin/ad-phase2.sh
chmod +x /usr/local/bin/bash-wrapper
service winbind restart
service nscd restart

Reboot for good measure.