Setting up Samba as a Domain Member: Difference between revisions

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= Introduction =
= Introduction =


A Samba domain member is a Linux machine joined to a domain that is running Samba and does not provide domain services, such as an NT4 primary domain controller (PDC) or Active Directory (AD) domain controller (DC).
In the context of Samba, you usually only hear about servers ([[Active_Directory_Domain_Controller|AD DCs]], [[NT4_Domains|NT4 PDCs]], [[File_sharing|file servers]], etc.). You usually do not hear much about a Samba workstation as a Domain Member, similar to hosts running a version of Windows e. g. Windows 10 Pro or some other workstation edition. What if you want to join a Linux workstation to the domain, to authenticate user logins against your Domain Controller(s)?


On a Samba domain member, you can:
Generally speaking, a Samba server is just a Samba workstation that provides file shares or print services. This is how we will structure our documentation here - being a Domain Member is the prerequisite for configuring a Samba [[File_sharing|file]] and/or [[Setup_a_Samba_print_server|print]] server.


* Use domain users and groups in local ACLs on files and directories.
* Set up shares to act as a file server.
* Set up printing services to act as a print server.
* Configure PAM to enable domain users to log on locally or to authenticate to local installed services.


For details about setting up a Samba NT4 domain or Samba AD, see [[Domain_Control|Domain Control]].








= Installation =


= Preparing the Installation =
You have the following options to install Samba:


== General Preparation ==
* [[Build_Samba_from_Source|Build Samba]] yourself


* Verify that no Samba processes are running:
* Install [[Distribution-specific_Package_Installation|distribution specific packages]]
# ps ax | egrep "samba|smbd|nmbd|winbindd"
: If the output lists any <code>samba</code>, <code>smbd</code>, <code>nmbd</code>, or <code>winbindd</code> processes, shut down the processes.


* If you previously run a Samba installation on this host:
* Install SerNet [http://www.samba.plus Samba+]/[http://www.samba.plus/older-packages/ Enterprise] packages
:* Remove the existing <code>smb.conf</code> file. To list the path to the file, enter:


# smbd -b | grep "CONFIGFILE"
CONFIGFILE: /usr/local/samba/etc/samba/smb.conf


:* Remove all Samba database files, such as <code>*.tdb</code> and <code>*.ldb</code> files. To list the folders containing Samba databases:


# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR"
LOCKDIR: /usr/local/samba/var/lock/
STATEDIR: /usr/local/samba/var/locks/
CACHEDIR: /usr/local/samba/var/cache/
PRIVATE_DIR: /usr/local/samba/private/


: Starting with a clean environment helps you to prevent confusion, and no files from your previous Samba installation are mixed with your new domain member installation.


= Preparing the host for the domain join =


== AD DNS zone resolution ==


== Preparing a Domain Member to Join an Active Directory Domain ==
Many things in an Active Directory, such as Kerberos, rely on DNS. Therefore it is required that the host is able to resolve AD DNS zones. If you have multiple DCs acting as a DNS server, it's recommended to setup multiple nameserver entries for fail over reasons.


=== Configuring DNS ===
On Linux and Unixes, you usually configure DNS settings in /etc/resolv.conf:


For details, see [[Linux_and_Unix_DNS_Configuration|Linux and Unix DNS Configuration]].
nameserver 10.99.0.1
nameserver 10.99.0.2
search samdom.example.com


Some tools, such as NetworkManager, may overwrite manual changes in that file. Please consult your distributions documentation for configuring name resolution.


To verify a correct name resolution, try resolving the hostname of one of your Domain Controllers:


=== Configuring Kerberos ===
# host -t A DC1.samdom.example.com
DC1.samdom.example.com has address 10.99.0.1


Samba supports Heimdal and MIT Kerberos back ends. To configure Kerberos on the domain member, set the following in your <code>/etc/krb5.conf</code> file:


[libdefaults]
default_realm = SAMDOM.EXAMPLE.COM
dns_lookup_realm = false
dns_lookup_kdc = true


The previous example configures Kerberos for the <code>SAMDOM.EXAMPLE.COM</code> realm.
== NTP ==


The Samba teams recommends not setting further parameters in the <code>/etc/krb5.conf</code> file.
In an Active Directory, accurate time synchronization is necessary for Kerberos, to prevent replay attacks and for resolving directory replication conflicts. For those reasons, if the time differs to your AD, your host won't be able to access AD servers and any shares it provides won't be accessible by others. See [[Time_Synchronisation|Time Syncronisation]] for further information and [[Time_Synchronisation#Configuring_time_synchronisation_on_a_Samba_Domain_Members|configuration examples]].






== Local hostname resolution ==



During the Domain join, Samba tries to register/update the hosts name and IP in your AD DNS. This requires that "net" can resolve both, either using DNS or /etc/hosts. To verify, run
=== Configuring Time Synchronisation ===

Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see [[Time_Synchronisation#Configuring_Time_Synchronisation_on_a_Unix_Domain_Member|Configuring Time Synchronisation on a Unix Domain Member]].



=== Local Host Name Resolution ===

When you join the host to the domain, Samba tries to register the host name in the AD DNS zone. For this, the <code>net</code> utility must be able to resolve the host name using DNS or using a correct entry in the <code>/etc/hosts</code> file.

To verify that your host name resolves correctly, use the <code>getent hosts</code> command. For example:


# getent hosts M1
# getent hosts M1
10.99.0.5 M1.samdom.example.com M1
10.99.0.5 M1.samdom.example.com M1


The host name and FQDN must not resolve to the <code>127.0.0.1</code> IP address or any other IP address other than the one used on the LAN interface of the domain member.
The commands output must show the correct LAN interface IP (not 127.*.*.*!) and the hostname including the AD DNS zone. Additional alias names are optional. If you get a different output, fix it in your DNS or by adding/changing the /etc/hosts entry:


If no output is displayed or the host is resolved to the wrong IP address and you are not using dhcp, set the correct entry in the <code>/etc/hosts</code> file. For example:

127.0.0.1 localhost
10.99.0.5 M1.samdom.example.com M1
10.99.0.5 M1.samdom.example.com M1


If you are using dhcp, check that <code>/etc/hosts</code> only contains the '127.0.0.1' line shown above. If you continue to have problems, contact the sysadmin who controls your DHCP server.
* On debian related systems you will also see the line <code>127.0.1.1 hostname</code> in /etc/hosts, remove it before you install samba.
* Please keep the line : <code>127.0.0.1 localhost</code>


if you need to add aliases to the machine hostname, add them to the end of the line that starts with the machines ipaddress, not the 127.0.0.1 line.






= Setup a Domain Member smb.conf file =


== Preparing a Domain Member to Join an NT4 Domain ==
Before joining a domain, it is necessary to create the Samba configuration file "smb.conf". The following command shows, where the file is located in your installation:


For joining a host to an NT4 domain, no preparation is required.
'''Note:''' You should use the same "smb.conf" file on all domain members you set up in the domain.


# smbd -b | grep CONFIGFILE
CONFIGFILE: /usr/local/samba/etc/smb.conf



In the following you see an smb.conf example sufficient to join a domain, if you add an "idmap config" part, fitting to your environment.


= Installing Samba =

For details, see [[Installing_Samba|Installing Samba]].


{{Imbox
{{Imbox
| type = important
| type = note
| text = Install a maintained Samba version. For details, see [[Samba_Release_Planning|Samba Release Planning]].
| text = The ID ranges of the <code>*</code> default domain and all other domains configured in the <code>smb.conf</code> file must not overlap.
}}
}}





= Configuring Samba =

== Setting up a Basic <code>smb.conf</code> File ==

When Setting up smb.conf on a Unix domain member, you will need to make a few decisions.

* Do you require users and groups to have the same IDs everywhere, including Samba AD DCs ?
* Do you only want your users and groups to have the same IDs on Unix domain members ?
After making your decision, you will have another decision to make, this decision could affect what you think you have already decided.
* Do you want or need individual users to have different login shells and/or Unix home directory paths ?

If you need your users to have different login shells and/or Unix home directory paths, or you want them to have the same ID everywhere, you will need to use the winbind 'ad' backend and add RFC2307 attributes to AD.

{{Imbox
| type = note
| text = The RFC2307 attributes are not added automatically when users or groups are created.
}}


If your users will only use the Samba AD DC for authentication and will not store data on it or log into it, you can use the the winbind 'rid' backend, this calculates the user and group IDs from the Windows RID, if you use the same [global] section of the smb.conf on every Unix domain member, you will get the same IDs.
If you use the 'rid' backend you do not need to add anything to AD and in fact, any RFC2307 attributes will be ignored.
When using the 'rid' backend you must set the 'template shell' and 'template homedir' parameters in smb.conf, these are global settings and everyone gets the same login shell and Unix home directory path, unlike the RFC2307 attributes where you can set individual Unix home directory paths and shells.
There is another way of setting up Samba, this is where you require your users and groups to have the same ID everywhere, but only need your users to have the same login shell and use the same Unix home directory path. You can do this by using the winbind 'ad' backend and using the template lines in smb.conf. This way you only have to add uidNumber & gidNumbers attributes to AD.

Having decided which winbind backend to use, you now have a further decision to make, the ranges to use with 'idmap config' in smb.conf.
By default on a Unix domain member, there are multiple blocks of users & groups:

* The local system users & groups: These will be from 0-999
* The local Unix users and groups: These start at 1000
* The 'well Known SIDs': ????
* The DOMAIN users and groups: ADUC, by default, starts these at 10000
* Trusted domains: ????
* Anything that isn't a 'well Known SID' or a member of DOMAIN or a trusted domain: ????


As you can see from the above, you shouldn't set either the '*' or 'DOMAIN' ranges to start at 999 or less, as they would interfere with the local system users & groups. You also should leave a space for any local Unix users & groups, so starting the 'idmap config' ranges at 3000 seems to be a good compromise.

You need to decide how large your 'DOMAIN' is likely to grow to and you also need to know if you have any trusted domains or if you may need to have any in future.

Bearing the above information in mind, you could set the 'idmap config' ranges to the following:

:{| class="wikitable"
!Domain
!Range
|-
|<code>*</code>
|'''3000-7999'''
|-
|<code>DOMAIN</code>
|'''10000-999999'''
|}

You could also have any trusted domains starting at:

:{| class="wikitable"
!Domain
!Range
|-
|<code>TRUSTED</code>
|'''1000000-9999999'''
|}

If you set the '*' range above the 'DOMAIN' range, the ranges will conflict if the 'Domain' grows to the point that the next ID would be the same as the '*' range start ID.

With the above suggested ranges, no range will overlap or interfere with another.

You may also have seen examples of the '*' range being used for everything, this is not recommended and should not be used.


Before joining the domain, configure the domain member's <code>smb.conf</code> file:

* To locate the file, enter:

# smbd -b | grep CONFIGFILE
CONFIGFILE: /usr/local/samba/etc/smb.conf

* After reading this wikipage, edit the <code>smb.conf</code> file and use this example configuration as a basis to set yours, do not just 'cut & paste' it:


[global]
[global]
Line 90: Line 207:
log level = 1
log level = 1
# idmap config used for your domain.
# Default ID mapping configuration for local BUILTIN accounts
# Click on the following links for more information
# and groups on a domain member. The default (*) domain:
# - must not overlap with any domain ID mapping configuration!
# on the available winbind idmap backends,
# - must use a read-write-enabled back end, such as <code>tdb</code>.
# Choose the one that fits your requirements
# then add the corresponding configuration.
# - '''Adding just this is not enough'''
# - '''You must set a DOMAIN backend configuration, see below'''
idmap config * : backend = tdb
idmap config * : backend = tdb
idmap config * : range = 1000000-1999999
idmap config * : range = 3000-7999
# Just adding one of the following three lines is not enough!!
# Please follow the links.
#
# - [[idmap_config_ad|use the winbind 'ad' backend.]]
# Or
# - [[idmap_config_rid|use the winbind 'rid' backend.]]
# Or
# - [https://www.samba.org/samba/docs/man/manpages-3/idmap_autorid.8.html use the winbind 'autorid' backend.]


:For information on the parameters, see the <code>smb.conf(5)</code> man page.
See the manpage of "smb.conf" for detailed information about the parameters and options used.


* '''You must add an ID mapping configuration, for each domain that you want Samba to be aware of, to the <code>[global]</code> section of your <code>smb.conf</code> file.'''
= The domain join =
* '''You must click on one of the following hyperlinks to find information about the Samba domain back ends:'''


:{| class="wikitable"
'''<u>A note on provisioning</u>:''' A Domain Member <u>must not</u> be provisioned by using "samba-tool"! This would setup an AD DC on your Domain Member with some parts turned off and writes to sam.ldb instead of passdb.tdb. Don't use this way to join, to avoid unwanted side effects! The Domain Member provisioning option will be removed in the future.
!Back End
!Documentation
!Man Page
|-
|<code>ad</code>
|'''[[Idmap_config_ad|idmap config ad]]'''
|<code>idmap_ad(8)</code>
|-
|<code>rid</code>
|'''[[Idmap_config_rid|idmap config rid]]'''
|<code>idmap_rid(8)</code>
|-
|<code>autorid</code>
|'''[[Idmap_config_autorid|idmap config autorid]]'''
|<code>idmap_autorid(8)</code>
|-
|<code>hash</code>
|[[Idmap_config_hash|idmap config hash]]
|<code>idmap_hash(8)</code>
|-
|<code>ldap</code>
|[[Idmap_config_ldap|idmap config ldap]]
|<code>idmap_ldap(8)</code>
|-
|<code>nss</code>
|[[Idmap_config_nss|idmap config nss]]
|<code>idmap_nss(8)</code>
|}


:{{Imbox
The following command will join the host to the domain and automatically register/update its DNS record:
| type = important
| text = Add an additional ID mapping configuration for every domain. The ID ranges of the default (<code>*</code>) domain and other domains configured in the <code>smb.conf</code> file must not overlap.
}}



== Mapping the Domain Administrator Account to the Local <code>root</code> User ==

Samba enables you to map domain accounts to a local account. Use this feature to execute file operations on the domain member's file system as a different user than the account that requested the operation on the client.

{{Imbox
| type = note
| text = Mapping the domain administrator to the local <code>root</code> account is optional. Only configure the mapping if the domain administrator must be able to execute file operations on the domain member using <code>root</code> permissions. You should be aware that mapping Administrator to the <code>root</code> account will not allow you to log onto Unix domain members as <code>Administrator</code>.
}}

To map the domain administrator to the local <code>root</code> account:

* Add the following parameter to the <code>[global]</code> section of your <code>smb.conf</code> file:

username map = /usr/local/samba/etc/user.map

* Create the <code>/usr/local/samba/etc/user.map</code> file with the following content:
!root = SAMDOM\Administrator

:{{Imbox
| type = important
| text = When using the <code>ad</code> ID mapping back end, do not set the <code>uidNumber</code> attribute for the domain administrator account. If the account has the attribute set, the value overrides the local UID <code>0</code> of the <code>root</code> user and thus the mapping fails.
}}

For further details, see <code>username map</code> parameter in the <code>smb.conf(5)</code> man page.





= Joining the Domain =

* To join the host to an Active Directory (AD), enter:


# net ads join -U administrator
# net ads join -U administrator
Line 120: Line 297:
Joined 'M1' to dns domain 'samdom.example.com'
Joined 'M1' to dns domain 'samdom.example.com'


* To join the host to an NT4 domain, enter:
If you encounter any error message(s), see [[Troubleshooting_Samba_Domain_Members|Troubleshooting Samba Domain Members]].


# net rpc join -U administrator
If you use the parameter : bind interfaces only = yes in smb.conf, join with :
# net ads join -U administrator -S addc.samdom.example.com
Enter administrator's password: Passw0rd
Joined domain SAMDOM.


{{Imbox
= libnss_winbind =
| type = important
| text = Do not provision or join a domain member using the <code>samba-tool</code> utility. These options are unsupported and can cause problems with your AD replication. The options will be removed from <code>samba-tool</code> in a future release.
}}


If you have problems joining the domain, check your configuration. For further help, see [[Troubleshooting_Samba_Domain_Members|Troubleshooting Samba Domain Members]].
Domain users and groups are made available to your local system through libnss_winbind. The [[#Setup_a_Domain_Member_smb.conf_file|smb.conf configuration]] was already done in a previous step. Next is to tell your system to retrieve that information from winbindd by adding "winbind" to the following two lines of your /etc/nsswitch.conf:


passwd: files winbind
group: files winbind


Keep the existing database "files" (sometimes you may find "compat" instead of "files"). It defines that accounts and groups are first looked up in local files (/etc/passwd and /etc/group), then using Winbindd.


'''Note:''' Do not add 'winbind' to the 'shadow' line, this has been reported to cause problems with 'wbinfo', it is also totally unneeded.


'''Note:''' you cannot have users & groups with the same name in the local files and the domain i.e. a user 'foo' that appears in /etc/passwd would be the same user as 'DOMAIN\foo', in this instance you would need to remove or rename one of the users.


= Configuring the Name Service Switch =
'''Important:''' If you have compiled Samba, you may need to add two symbolic links. See [[Libnss_winbind_Links|libnss_winbind Links]] for OS specific information on where to place them. Samba package installations usually place the file directly in the OS library path or have the links included.


To enable the name service switch (NSS) library to make domain users and groups available to the local system:


* Append the <code>winbind</code> entry to the following databases in the <code>/etc/nsswitch.conf</code> file:


passwd: files <u>winbind</u>
group: files <u>winbind</u>


:* Keep the <code>files</code> entry as first source for both databases. This enables NSS to look up domain users and groups from the <code>/etc/passwd</code> and <code>/etc/group</code> files before querying the Winbind service.


:* Do not add the <code>winbind</code> entry to the NSS <code>shadow</code> database. This can cause the <code>wbinfo</code> utility fail.
= Start daemons =


:{{Imbox
Depending on how you use your Domain Member, you have to start different daemons:
| type = note
| text = Do not use the same user names in the local <code>/etc/passwd</code> file as in the domain.
}}


* If you compiled Samba, add symbolic links from the <code>libnss_winbind</code> library to the operating system's library path. For details, see [[Libnss_winbind_Links|libnss_winbind Links]]. If you used packages to install Samba, the link is usually created automatically.
For a pure Domain Member (domain logons only):


# winbindd


For Domain Members [[File_sharing|sharing directories (file server)]] and/or [[Setup_a_Samba_print_server|printers (print server)]]:


# smbd
# nmbd
# winbindd


'''Note:''' You do not start the 'samba' daemon on a domain member.


= Starting the Services =
If you installed Samba using packages, you usually have init scripts or systemd/upstart support included. If you have compiled Samba, you will need to write your own scripts. For automatic startup of the service(s) at boot time, please consult you distributions documentation.


To start the services on a domain member:


* Start the <code>winbindd</code> service to enable the name service switch (NSS) library to look up domain users and groups:


# winbindd


* If you set up file shares or printer services on the domain member, additionally start the <code>smbd</code> and <code>nmbd</code> service:


# smbd
= Testing Winbindd domain controller connectivity =
# nmbd


:{{Imbox
== wbinfo ==
| type = note
| text = You must not start the <code>samba</code> service on a domain member. This service is required only on Active Directory (AD) domain controllers (DC).
}}


Samba does not provide System V init scripts, <code>systemd</code>, <code>upstart</code>, or service files for other init services.
You first need to check if winbind is able to connect to a domain controller with wbinfo --ping-dc:
* If you installed Samba using packages, use the script or service configuration file provided by the package to start Samba.
* If you built Samba, see your distribution's documentation for how to create a script or configuration to start services.


# wbinfo --ping-dc
checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded




== Using domain accounts/groups in OS commands ==


If you have included [[#libnss_winbind|libnss_winbind]] in your system and setup smb.conf correctly, the following commands should print the relevant information for the supplied user or group:


= Testing the Winbindd Connectivity =
# getent passwd demo01
demo01:*:10000:10000:demo01:/home/demo01:/bin/bash
...


== Sending a Winbindd Ping ==
# getent group Domain\ Users
domain users:x:10000:
...


To verify if the Winbindd service is able to connect to Active Directory (AD) Domain Controllers (DC) or a primary domain controller (PDC), enter:


# wbinfo --ping-dc
'''Note:''' If you do not get any output, verify that
checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded
* [[#libnss_winbind|libnss_winbind]] configuration is correct - especially that "ldconfig" is able to find "libnss_winbind.so.2" and "libnss_winbind.so"
* smb.conf is setup correctly
* if using [[idmap_config_ad|idmap config ad]], accounts/groups have [[Maintaining_Unix_Attributes_in_AD_using_ADUC|RFC2307 attributes]] set


If the previous command fails, verify:
* That the <code>winbindd</code> service is running.
* Your <code>smb.conf</code> file is set up correctly.


'''Note:''' if you want to display all users & groups with 'getent', add these lines to your smb.conf (This is only recommended for testing):
winbind enum users = yes
winbind enum groups = yes




== Using Domain Accounts and Groups in Operating System Commands ==
Any domain accounts/groups shown by getent or id can be used in the OS, i.e.


=== Looking up Domain Users and Groups ===
# id demo01
uid=10000(demo01) gid=10000(domain users) groups=10000(domain users),2001(BUILTIN\users)


The <code>libnss_winbind</code> library enables you to look up domain users and groups. For example:
# chown demo01:"domain users" file.txt
# ls -s file.txt
-rw-------. 1 demo01 domain users 992 18. Oct 2015 file.txt


* To look up the domain user <code>SAMDOM\demo01</code>:


# getent passwd SAMDOM\\demo01
'''Note:''' For various reasons, Administrator needs to be mapped to the Unix user 'root', this is done automatically on a Samba AD DC. On a domain member you will need to add a line to 'smb.conf':
SAMDOM\demo01:*:10000:10000:demo01:/home/demo01:/bin/bash


* To look up the domain group <code>Domain Users</code>:
username map = /usr/local/samba/etc/user.map


# getent group "SAMDOM\\Domain Users"
You will then need to create /usr/local/samba/etc/user.map:
SAMDOM\domain users:x:10000:
!root = SAMDOM\Administrator SAMDOM\administrator Administrator administrator


Do not give Administrator a uidNumber attribute, this will turn Administrator into a normal Unix user, without the required permissions & rights it needs.




= Authenticating Domain Users Using PAM =
=== Assigning File Permissions to Domain Users and Groups ===


The name service switch (NSS) library enables you to use domain user accounts and groups in commands. For example to set the owner of a file to the <code>demo01</code> domain user and the group to the <code>Domain Users</code> domain group, enter:
''If you have setup this Domain Member as a server providing file shares or print services, you may want to skip this part, By following this part, you will allow domain users to logon locally to the hosts console.''


# chown "SAMDOM\\demo01:SAMDOM\\domain users" file.txt




== General information ==


'''Important note:''' Before you start changing your PAM configuration:
* make sure you know what you're doing!
* before you start, login within a second terminal and keep it open until everything works as expected. Otherwise, you may lockout yourself and won't be able to login again!


If you have compiled Samba, you need to add a symbolic links. See [[Pam_winbind_Link|pam_winbind Link]] for OS specific information, where to place it. Samba package installations usually place the file directly in the right folder or have a link included.


= Setting up Additional Services on the Domain Member =


On a Samba domain member, you can additionally set up:
* File shares to act as a file server. For details, see [[Samba_File_Serving|Samba File Serving]].
* Print services to act as a print server. For details, see [[Print_Server_Support|Print Server Support]].
* PAM authentication of domain users for local services. For details, see [[Authenticating_Domain_Users_Using_PAM|Authenticating Domain Users Using PAM]].


== Configure PAM ==


'''Note:''' Whenever your distribution ship tools to configure PAM, it's recommended to use them, instead of manually editing the configuration files!
* Red Hat based OS: authconfig/authconfig-tui
* Debian based OS: pam-auth-update
* SUSE based OS: yast


For manual changes: Typically the PAM configuration files are located in /etc/pam.d/ Depending on your distribution, the filename(s) may differ. E. g. on RHEL, you configure system login authentication in /etc/pam.d/password-auth-ac:


#%PAM-1.0
auth required pam_env.so
auth sufficient pam_unix.so nullok try_first_pass
auth requisite pam_succeed_if.so uid >= 1000 quiet_success
auth sufficient pam_winbind.so use_first_pass # <-- add this line
auth required pam_deny.so
account required pam_unix.so broken_shadow
account sufficient pam_localuser.so
account sufficient pam_succeed_if.so uid < 1000 quiet
account [default=bad success=ok user_unknown=ignore] pam_winbind.so # <-- add this line
account required pam_permit.so
password requisite pam_cracklib.so try_first_pass retry=3 type=
password sufficient pam_unix.so sha512 shadow nullok try_first_pass use_authtok
password sufficient pam_winbind.so use_authtok # <-- add this line
password required pam_deny.so
session optional pam_keyinit.so revoke
session required pam_limits.so
session [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid
session required pam_unix.so


= Troubleshooting =
For additional information about PAM configuration and settings used in the example above, please consult the [http://www.linux-pam.org PAM] documentation and the manpages of pam.conf and pam_winbind.


For details, see [[Troubleshooting_Samba_Domain_Members|Troubleshooting Samba Domain Members]].



== Verify domain user login ==

Try to login on the local console with a domain user account:

CentOS Linux 7 (Core)
Kernel 3.10.0-229.11.1.el.7.x86_64 on an x86_64
M1 login: demo01
Password: Passw0rd
[demo01@M1 ~]$ _






= Setting up additional services =


----
Now you have successfully made your host be a Domain Member, you can, as on a Windows OS, additionally [[File_sharing|share directories (file server)]] or act as an [[Setup_a_Samba_print_server|print server]].
[[Category:Active Directory]]
[[Category:Domain Members]]
[[Category:NT4 Domains]]

Revision as of 20:55, 27 November 2017

Introduction

A Samba domain member is a Linux machine joined to a domain that is running Samba and does not provide domain services, such as an NT4 primary domain controller (PDC) or Active Directory (AD) domain controller (DC).

On a Samba domain member, you can:

  • Use domain users and groups in local ACLs on files and directories.
  • Set up shares to act as a file server.
  • Set up printing services to act as a print server.
  • Configure PAM to enable domain users to log on locally or to authenticate to local installed services.

For details about setting up a Samba NT4 domain or Samba AD, see Domain Control.



Preparing the Installation

General Preparation

  • Verify that no Samba processes are running:
# ps ax | egrep "samba|smbd|nmbd|winbindd"
If the output lists any samba, smbd, nmbd, or winbindd processes, shut down the processes.
  • If you previously run a Samba installation on this host:
  • Remove the existing smb.conf file. To list the path to the file, enter:
# smbd -b | grep "CONFIGFILE"
   CONFIGFILE: /usr/local/samba/etc/samba/smb.conf
  • Remove all Samba database files, such as *.tdb and *.ldb files. To list the folders containing Samba databases:
# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR"
  LOCKDIR: /usr/local/samba/var/lock/
  STATEDIR: /usr/local/samba/var/locks/
  CACHEDIR: /usr/local/samba/var/cache/
  PRIVATE_DIR: /usr/local/samba/private/
Starting with a clean environment helps you to prevent confusion, and no files from your previous Samba installation are mixed with your new domain member installation.


Preparing a Domain Member to Join an Active Directory Domain

Configuring DNS

For details, see Linux and Unix DNS Configuration.


Configuring Kerberos

Samba supports Heimdal and MIT Kerberos back ends. To configure Kerberos on the domain member, set the following in your /etc/krb5.conf file:

[libdefaults]
	default_realm = SAMDOM.EXAMPLE.COM
	dns_lookup_realm = false
	dns_lookup_kdc = true

The previous example configures Kerberos for the SAMDOM.EXAMPLE.COM realm.

The Samba teams recommends not setting further parameters in the /etc/krb5.conf file.



Configuring Time Synchronisation

Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see Configuring Time Synchronisation on a Unix Domain Member.


Local Host Name Resolution

When you join the host to the domain, Samba tries to register the host name in the AD DNS zone. For this, the net utility must be able to resolve the host name using DNS or using a correct entry in the /etc/hosts file.

To verify that your host name resolves correctly, use the getent hosts command. For example:

# getent hosts M1
10.99.0.5      M1.samdom.example.com    M1

The host name and FQDN must not resolve to the 127.0.0.1 IP address or any other IP address other than the one used on the LAN interface of the domain member.

If no output is displayed or the host is resolved to the wrong IP address and you are not using dhcp, set the correct entry in the /etc/hosts file. For example:

127.0.0.1      localhost
10.99.0.5      M1.samdom.example.com    M1

If you are using dhcp, check that /etc/hosts only contains the '127.0.0.1' line shown above. If you continue to have problems, contact the sysadmin who controls your DHCP server.

  • On debian related systems you will also see the line 127.0.1.1 hostname in /etc/hosts, remove it before you install samba.
  • Please keep the line : 127.0.0.1 localhost

if you need to add aliases to the machine hostname, add them to the end of the line that starts with the machines ipaddress, not the 127.0.0.1 line.



Preparing a Domain Member to Join an NT4 Domain

For joining a host to an NT4 domain, no preparation is required.



Installing Samba

For details, see Installing Samba.



Configuring Samba

Setting up a Basic smb.conf File

When Setting up smb.conf on a Unix domain member, you will need to make a few decisions.

  • Do you require users and groups to have the same IDs everywhere, including Samba AD DCs ?
  • Do you only want your users and groups to have the same IDs on Unix domain members ?

After making your decision, you will have another decision to make, this decision could affect what you think you have already decided.

  • Do you want or need individual users to have different login shells and/or Unix home directory paths ?

If you need your users to have different login shells and/or Unix home directory paths, or you want them to have the same ID everywhere, you will need to use the winbind 'ad' backend and add RFC2307 attributes to AD.


If your users will only use the Samba AD DC for authentication and will not store data on it or log into it, you can use the the winbind 'rid' backend, this calculates the user and group IDs from the Windows RID, if you use the same [global] section of the smb.conf on every Unix domain member, you will get the same IDs. If you use the 'rid' backend you do not need to add anything to AD and in fact, any RFC2307 attributes will be ignored. When using the 'rid' backend you must set the 'template shell' and 'template homedir' parameters in smb.conf, these are global settings and everyone gets the same login shell and Unix home directory path, unlike the RFC2307 attributes where you can set individual Unix home directory paths and shells.

There is another way of setting up Samba, this is where you require your users and groups to have the same ID everywhere, but only need your users to have the same login shell and use the same Unix home directory path. You can do this by using the winbind 'ad' backend and using the template lines in smb.conf. This way you only have to add uidNumber & gidNumbers attributes to AD.

Having decided which winbind backend to use, you now have a further decision to make, the ranges to use with 'idmap config' in smb.conf. By default on a Unix domain member, there are multiple blocks of users & groups:

  • The local system users & groups: These will be from 0-999
  • The local Unix users and groups: These start at 1000
  • The 'well Known SIDs':  ????
  • The DOMAIN users and groups: ADUC, by default, starts these at 10000
  • Trusted domains:  ????
  • Anything that isn't a 'well Known SID' or a member of DOMAIN or a trusted domain: ????


As you can see from the above, you shouldn't set either the '*' or 'DOMAIN' ranges to start at 999 or less, as they would interfere with the local system users & groups. You also should leave a space for any local Unix users & groups, so starting the 'idmap config' ranges at 3000 seems to be a good compromise.

You need to decide how large your 'DOMAIN' is likely to grow to and you also need to know if you have any trusted domains or if you may need to have any in future.

Bearing the above information in mind, you could set the 'idmap config' ranges to the following:

Domain Range
* 3000-7999
DOMAIN 10000-999999

You could also have any trusted domains starting at:

Domain Range
TRUSTED 1000000-9999999

If you set the '*' range above the 'DOMAIN' range, the ranges will conflict if the 'Domain' grows to the point that the next ID would be the same as the '*' range start ID.

With the above suggested ranges, no range will overlap or interfere with another.

You may also have seen examples of the '*' range being used for everything, this is not recommended and should not be used.


Before joining the domain, configure the domain member's smb.conf file:

  • To locate the file, enter:
# smbd  -b | grep CONFIGFILE
  CONFIGFILE: /usr/local/samba/etc/smb.conf
  • After reading this wikipage, edit the smb.conf file and use this example configuration as a basis to set yours, do not just 'cut & paste' it:
[global]
       security = ADS
       workgroup = SAMDOM
       realm = SAMDOM.EXAMPLE.COM

       log file = /var/log/samba/%m.log
       log level = 1

       # Default ID mapping configuration for local BUILTIN accounts
       # and groups on a domain member. The default (*) domain:
       # - must not overlap with any domain ID mapping configuration!
       # - must use a read-write-enabled back end, such as tdb.
       # - Adding just this is not enough
       # - You must set a DOMAIN backend configuration, see below
       idmap config * : backend = tdb
       idmap config * : range = 3000-7999
For information on the parameters, see the smb.conf(5) man page.
  • You must add an ID mapping configuration, for each domain that you want Samba to be aware of, to the [global] section of your smb.conf file.
  • You must click on one of the following hyperlinks to find information about the Samba domain back ends:
Back End Documentation Man Page
ad idmap config ad idmap_ad(8)
rid idmap config rid idmap_rid(8)
autorid idmap config autorid idmap_autorid(8)
hash idmap config hash idmap_hash(8)
ldap idmap config ldap idmap_ldap(8)
nss idmap config nss idmap_nss(8)


Mapping the Domain Administrator Account to the Local root User

Samba enables you to map domain accounts to a local account. Use this feature to execute file operations on the domain member's file system as a different user than the account that requested the operation on the client.

To map the domain administrator to the local root account:

  • Add the following parameter to the [global] section of your smb.conf file:
username map = /usr/local/samba/etc/user.map
  • Create the /usr/local/samba/etc/user.map file with the following content:
!root = SAMDOM\Administrator

For further details, see username map parameter in the smb.conf(5) man page.



Joining the Domain

  • To join the host to an Active Directory (AD), enter:
# net ads join -U administrator
Enter administrator's password: Passw0rd
Using short domain name -- SAMDOM
Joined 'M1' to dns domain 'samdom.example.com'
  • To join the host to an NT4 domain, enter:
# net rpc join -U administrator
Enter administrator's password: Passw0rd
Joined domain SAMDOM.

If you have problems joining the domain, check your configuration. For further help, see Troubleshooting Samba Domain Members.



Configuring the Name Service Switch

To enable the name service switch (NSS) library to make domain users and groups available to the local system:

  • Append the winbind entry to the following databases in the /etc/nsswitch.conf file:
passwd: files winbind
group:  files winbind
  • Keep the files entry as first source for both databases. This enables NSS to look up domain users and groups from the /etc/passwd and /etc/group files before querying the Winbind service.
  • Do not add the winbind entry to the NSS shadow database. This can cause the wbinfo utility fail.
  • If you compiled Samba, add symbolic links from the libnss_winbind library to the operating system's library path. For details, see libnss_winbind Links. If you used packages to install Samba, the link is usually created automatically.



Starting the Services

To start the services on a domain member:

  • Start the winbindd service to enable the name service switch (NSS) library to look up domain users and groups:
# winbindd
  • If you set up file shares or printer services on the domain member, additionally start the smbd and nmbd service:
# smbd
# nmbd

Samba does not provide System V init scripts, systemd, upstart, or service files for other init services.

  • If you installed Samba using packages, use the script or service configuration file provided by the package to start Samba.
  • If you built Samba, see your distribution's documentation for how to create a script or configuration to start services.



Testing the Winbindd Connectivity

Sending a Winbindd Ping

To verify if the Winbindd service is able to connect to Active Directory (AD) Domain Controllers (DC) or a primary domain controller (PDC), enter:

# wbinfo --ping-dc
checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded

If the previous command fails, verify:

  • That the winbindd service is running.
  • Your smb.conf file is set up correctly.


Using Domain Accounts and Groups in Operating System Commands

Looking up Domain Users and Groups

The libnss_winbind library enables you to look up domain users and groups. For example:

  • To look up the domain user SAMDOM\demo01:
# getent passwd SAMDOM\\demo01
SAMDOM\demo01:*:10000:10000:demo01:/home/demo01:/bin/bash
  • To look up the domain group Domain Users:
# getent group "SAMDOM\\Domain Users"
SAMDOM\domain users:x:10000:


Assigning File Permissions to Domain Users and Groups

The name service switch (NSS) library enables you to use domain user accounts and groups in commands. For example to set the owner of a file to the demo01 domain user and the group to the Domain Users domain group, enter:

# chown "SAMDOM\\demo01:SAMDOM\\domain users" file.txt



Setting up Additional Services on the Domain Member

On a Samba domain member, you can additionally set up:



Troubleshooting

For details, see Troubleshooting Samba Domain Members.