This example shows to configure on the environment below.

• Domain Server : Windows Server 2016
• NetBIOS Name : SW1S01
• Domain Name : srv.sharewiz
• Realm : SRV.SHAREWIZ
• Hostname : sw1s.srv.sharewiz

sudo apt install winbind libpam-winbind libnss-winbind krb5-config

and answer:

# set Realm
 
 +------------------+ Configuring Kerberos Authentication +------------------+
 | When users attempt to use Kerberos and specify a principal or user name   |
 | without specifying what administrative Kerberos realm that principal      |
 | belongs to, the system appends the default realm.  The default realm may  |
 | also be used as the realm of a Kerberos service running on the local      |
 | machine.  Often, the default realm is the uppercase version of the local  |
 | DNS domain.                                                               |
 |                                                                           |
 | Default Kerberos version 5 realm:                                         |
 |                                                                           |
 | SRV.SHAREWIZ_____________________________________________________________ |
 |                                                                           |
 |                                  <Ok>                                     |
 |                                                                           |
 +---------------------------------------------------------------------------+
 
# specify hostname of AD DS
 
     +--------------+ Configuring Kerberos Authentication +---------------+
     | Enter the hostnames of Kerberos servers in the SRV.SHAREWIZ        |
     | Kerberos realm separated by spaces.                                |
     |                                                                    |
     | Kerberos servers for your realm:                                   |
     |                                                                    |
     | sw1s.srv.sharewiz_________________________________________________ |
     |                                                                    |
     |                               <Ok>                                 |
     |                                                                    |
     +--------------------------------------------------------------------+
 
# specify hostname of AD DS
 
 +------------------+ Configuring Kerberos Authentication +------------------+
 | Enter the hostname of the administrative (password changing) server for   |
 | the SRV.SHAREWIZ Kerberos realm.                                          |
 |                                                                           |
 | Administrative server for your Kerberos realm:                            |
 |                                                                           |
 | sw1s.srv.sharewiz________________________________________________________ |
 |                                                                           |
 |                                  <Ok>                                     |
 |                                                                           |
 +------------------------------

Edit the samba config file as root: /etc/samba/smb.conf

/etc/samba/smb.conf

# line 29: change NetBIOS Name to AD DS's one and add like follows
   workgroup = SW1S01
 
   password server = sw1s.srv.sharewiz
   realm = SRV.SHAREWIZ
   security = ads
   idmap config * : range = 16777216-33554431
   template homedir = /home/%U
   template shell = /bin/bash
   winbind use default domain = true
   winbind offline logon = false 

Edit the nsswitch config file as root: /etc/nsswitch.conf

/etc/nsswitch.conf

# line 7: add like follows
 
passwd:     compat systemd winbind
 
group:     compat systemd winbind
 
shadow:     compat winbind

Edit the PAM config as root: /etc/pam.d/common-session

/etc/pam.d/common-session

# add to the end if you need (auto create a home directory at initial login)
 
session optional        pam_mkhomedir.so skel=/etc/skel umask=077

Edit netplan config.

/etc/netplan/01-netcfg.yaml

# change DNS to refer to AD
 
      nameservers:
        addresses: [192.168.1.1.8]

Apply netplan changes:

sudo netplan apply

Join Active Directory (net ads join -U [AD's admin user])

sudo net ads join -U Administrator
 
Enter Administrator's password:
Using short domain name -- SW1S01
Joined 'SMB' to dns domain 'srv.sharewiz'

Restart winbind

sudo systemctl restart winbind

wbinfo -u

returns:

administrator
guest
defaultaccount
peter

Try to switch to an AD user

sudo su - serverworld
 
Creating directory '/home/peter'.
peter@smb:~$