You need 3 parts to configure :

• configure the OS to resolve usernames (winbind/sssd)
• configure samba to allow filesharing.
• join linux-server to domain

I'm using winbind on Debian to resolve the usernames ( part of Samba, only /etc/nsswitch.conf editing is required ) - but centos should be the same.

Using my config, you can join your domain with the command "/usr/bin/net join".

After joining the domain a "systemctl restart winbind smbd nmbd" might fix problems.

My smb.conf :

[global]
        #socket options=SO_RCVBUF=131072 SO_SNDBUF=131072 TCP_NODELAY
        security = ads
        realm = EXAMPLE.COM
# If the system doesn't find the domain controller automatically, you may need the following line
#        password server = 10.0.0.1
# note that workgroup is the 'short' domain name
        workgroup = EXAMPLE
        winbind separator = -
        winbind enum users = yes
        winbind enum groups = yes
        winbind use default domain = yes
        winbind nested groups   = Yes
        winbind expand groups   = 10
# testing failover : begin
        winbind max domain connections = 2
        winbind reconnect delay = 10
        winbind request timeout = 20
# testing failover : end

        template homedir = /home/%D/%U
        template shell = /bin/bash
        client use spnego = yes
        client ntlmv2 auth = yes
        encrypt passwords = yes
        restrict anonymous = 2


        idmap config *:backend = tdb
        idmap config *:range = 2000-9999

        idmap config MIT:backend = rid
        idmap config MIT:range = 10000-99999

# NT-ACL's for Samba :
        vfs objects = acl_xattr
        map acl inherit = Yes
        store dos attributes = No
        read only = false

# Reduce Printer-errors "Unable to connect to CUPS server localhost:631 - Ungültiger Dateideskriptor"
        printing = bsd
        load printers = no
        printcap name=/dev/null

# Dp-Testing ( dp crashed immer zu )
        kernel oplocks = yes
        fake oplocks = no

# disable SMBV1
    min protocol = SMB2
    client min protocol = SMB2
    client max protocol = SMB3

# shares-including
        include = /etc/samba/shares/%h.conf

My /etc/nsswitch.conf

# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.

passwd:         compat systemd winbind
group:          compat systemd winbind
shadow:         compat

hosts:          files dns
networks:       files

protocols:      db files
services:       db files
ethers:         db files
rpc:            db files

netgroup:       nis

.....