Ubuntu 16.04 Desktop an das Active Directory anbinden

Nach der Grundinstallation von Ubuntu 16.04 LTS Desktop, wird das System auf den neusten Stand gebracht.

sudo su - oder sudo -i
apt update -y && apt upgrade -y

Nach dem das System up to date ist, kann man manuell die Netzwerkkarte konfigurieren, wichtig ist hier das der DNS Server vom Domaincontroller angesprochen wird.

cp /etc/hosts{,.old}
nano /etc/hosts

##### /etc/hosts ##################################
127.0.0.1 localhost
192.168.xxx.xxx clienthostname.htdom.local clienthostname
192.168.xxx.xxx ads01.htdom.local ads01 htdom.local
###################################################

dig -t SRV _ldap._tcp.htdom.local | grep -A2 "ANSWER SECTION

;; ANSWER SECTION:
_ldap._tcp.htdom.local. 600 IN SRV 0 100 389 ads01.htdom.local.

apt install fping

fping ads01.htdom.local
fping htdom.local
fping ads01
ads01.htdom.local is alive

Wenn der DNS Server für den Client konfiguriert wurde, installieren wir alle benötigten Pakete um den Client an das AD anzubinden.

apt install realmd sssd sssd-tools samba-common krb5-user packagekit samba-common-bin samba-libs adcli ntp vim -y

NTP Service konfigurieren

cp /etc/ntp.{conf,old}
nano /etc/ntp.conf

##### /etc/ntp.conf ###############################
server ads01.htdom.local
################################################### 

systemctl start ntp.service
systemctl status ntp.service

Realmd konfigurieren

nano /etc/realmd.conf

##### /etc/realmd.conf ############################
[users]
default-home = /home/%D/%U
  ## default-home = /home/%U@%D
  ## default-home = /nfs/home/%D-%U
default-shell = /bin/bash
  ## default-shell = /bin/sh

[active-directory]
default-client = sssd
  ## default-client = winbind
os-name = Ubuntu Linux Desktop
os-version = 16.04

[service]
automatic-install = no
  ## automatic-install = yes

[htdom.local]
computer-ou = OU=Clients,OU=Company,DC=htdom,DC=local
fully-qualified-names = no
automatic-id-mapping = yes
user-principal = yes
manage-system = no
###################################################

 

default-home: set the default homedir for each Active Directory User. In our example it will be something like /home/dom.example.int/domainuser.
default-shell: the default shell used by the users. bash is usually the preferred default shell.

default-client: we are using sssd in our scenario. winbind is also a possible option.
os-name: the operating system name as it will appear in our Active Directory.
os-version: the operating system version as it will appear in our Active Directory.

automatic-install: we want to prevent realmd to try to install its dependencies.

fully-qualified-names: this will allow users to use just their username instead of the combination of domain and username. For example we can use the username domainuser instead of DOM\domainuser or domainuser@dom.example.int. Note, however, that this could cause conflicts with local users, if they have the same username as a domain user.
automatic-id-mapping: this option will auto-generate the user and group ids (UID, GID) for newly created users, if set to yes.
user-principal: this will set the necessary attributes for the Ubuntu machine when it joins the domain.
manage-system: if you don’t want policies from the Active Directory environment to be applied on this machine, set this option to no.

 

Kerberos konfigurieren

cp /etc/krb5.{conf,old} && rm -rf /etc/krb5.conf
nano /etc/krb5.conf

##### /etc/krb5.conf ##############################
[logging]
	default = FILE:/var/log/krb5/krb5.log
	kdc = FILE:/var/log/krb5/krb5kdc.log
	admin_server = FILE:/var/log/krb5/kadmind.log

[libdefaults] 
	default_realm = HTDOM.LOCAL
	clockskew = 300

## The following krb5.conf variables are only for MIT Kerberos. 
	kdc_timesync = 1 
	ccache_type = 4 
	forwardable = true 
	proxiable = true 

[realms] 
	HTDOM.LOCAL = {
	kdc = ads01.htdom.local
  default_domain = htdom.local
  admin_server = ads01.htdom.local
}
 
[domain_realm] 
	.htdom.local = HTDOM.LOCAL
	htdom.local = HTDOM.LOCAL
###################################################

Client zur Domain hinzufügen

realm discover htdom.local
realm --verbose join htdom.local --user-principal=administrator@HTDOM.LOCAL

## Wer darf sich am System anmelden?
realm deny --all
realm permit helmut.thurnhofer
realm list

## Alle Domainadmins dürfen sich am System anmelden.
realm permit --groups Domänen-Admins@htdom.local

## Domain Admins der sudoers hinzufügen
visudo
%Domänen-Admins@htdom.local ALL=(ALL:ALL) ALL

AD Account berechtigen
usermod -a -G adm,cdrom,sudo,dip,plugdev,lpadmin,sambashare username

SSSD konfigurieren

cat /etc/sssd/sssd.conf

## cp /etc/sssd/sssd.{conf,old} && rm -rf /etc/sssd/sssd.conf
## nano /etc/sssd/sssd.conf

### /etc/sssd/sssd.conf ###########################
[sssd]
  domains = htdom.local
  config_file_version = 2
  services = nss, pam

[domain/htdom.local]
  ad_domain = htdom.local
  krb5_realm = HTDOM.LOCAL
  realmd_tags = joined-with-adcli
  cache_credentials = True
  id_provider = ad
  krb5_store_password_if_offline = True
  default_shell = /bin/bash
  ldap_id_mapping = True
  use_fully_qualified_names = False
  fallback_homedir = /home/%d/%u
  simple_allow_users = $
  access_provider = simple
###################################################

ls -la /etc/sssd/sssd.conf
-rw------- 1 root root 486 Sep 18 01:07 /etc/sssd/sssd.conf
## chown root:root /etc/sssd/sssd.conf
## chmod 600 /etc/sssd/sssd.conf

systemctl start sssd.service
systemctl enable sssd.service
systemctl status sssd.service

Pam common-session konfigurieren für das Home Laufwerk

cp /etc/pam.d/common-session /etc/pam.d/common-session.old
nano /etc/pam.d/common-session

session required pam_mkhomedir.so umask=0022 skel=/etc/skel
## echo "session required pam_mkhomedir.so skel=/etc/skel/ umask=0022" | sudo tee -a /etc/pam.d/common-session

Ubuntu 16.04 Login anpassen

nano /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

greeter-show-manual-login=true
greeter-hide-users=true

So das war es schon wieder

Viel Spaß damit
Gruß Helmut