Setting up Samba as a Domain Member: Difference between revisions

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== Preparing a Domain Member to Join an Active Directory Domain ==
== Preparing a Domain Member to Join an Active Directory Domain ==


== Configuring DNS ==
=== Configuring DNS ===


For details, see [[Linux_and_Unix_DNS_Configuration|Linux and Unix DNS Configuration]].
For details, see [[Linux_and_Unix_DNS_Configuration|Linux and Unix DNS Configuration]].
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== Configuring Kerberos ==
=== Configuring Kerberos ===


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:
Samba is either compiled against Heimdal Kerberos or MIT Kerberos.

The Kerberos file <code>/etc/krb5.conf</code> needs to only contain the following:


[libdefaults]
[libdefaults]
Line 61: Line 59:
dns_lookup_kdc = true
dns_lookup_kdc = true


The previous example configures Kerberos for the <code>SAMDOM.EXAMPLE.COM</code> realm.
Using anything other than the above, could lead to errors.

The Samba teams recommends to no set any further parameters in the <code>/etc/krb5.conf</code> file.

If your <code>/etc/krb5.conf</code> contains an <code>include</code> line it will not work, you '''Must''' remove this line.





You will need to replace <code>SAMDOM.EXAMPLE.COM</code> with your KERBEROS realm.


= Configuring Time Synchronisation =
=== 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]].
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]].
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== Local Host Name Resolution ==
=== 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.
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.
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For joining a host to an NT4 domain, no preparation is required.
For joining a host to an NT4 domain, no preparation is required.






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


{{Imbox
| type = important
| text = The ID numbers found on a DC (numbers in the 3000000 range) are NOT rfc2307 attributes They cannot and will not be used on Unix Domain Members, if you want to have the same ID numbers everywhere, you must add uidNumber & gidNumber attributes to AD and use the winbind 'ad' backend on Unix Domain Members. If you do decide to add uidNumber & gidNumber attributes to AD, you do not need to use numbers in the 3000000 range and in fact it would definitely be a good idea to use a different range.
}}



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:
Before joining the domain, configure the domain member's <code>smb.conf</code> file:
Line 124: Line 206:
CONFIGFILE: /usr/local/samba/etc/smb.conf
CONFIGFILE: /usr/local/samba/etc/smb.conf


* Edit the <code>smb.conf</code> file and set the following configuration:
* 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]
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# - must not overlap with any domain ID mapping configuration!
# - must not overlap with any domain ID mapping configuration!
# - must use a read-write-enabled back end, such as <code>tdb</code>.
# - must use a read-write-enabled back end, such as <code>tdb</code>.
# - Adding just this is not enough
# - '''Adding just this is not enough'''
# - You must set a DOMAIN backend configuration, see below
# - '''You must set a DOMAIN backend configuration, see below'''
idmap config * : backend = tdb
idmap config * : backend = tdb
idmap config * : range = 1000000-2000000
idmap config * : range = 3000-7999


:For information on the parameters, see the <code>smb.conf(5)</code> man page.
:For information on the parameters, see the <code>smb.conf(5)</code> man page.
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| 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.
| 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 ==
== Mapping the Domain Administrator Account to the Local <code>root</code> User ==
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{{Imbox
{{Imbox
| type = note
| 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.
| 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>.
}}
}}


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# getent group "SAMDOM\\Domain Users"
# getent group "SAMDOM\\Domain Users"
SAMDOM\domain users:x:10000:
SAMDOM\domain users:x:10000:




=== Assigning File Permissions to Domain Users and Groups ===
=== Assigning File Permissions to Domain Users and Groups ===
Line 325: Line 411:


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






= Setting up Additional Services on the Domain Member =
= Setting up Additional Services on the Domain Member =

Revision as of 10:31, 4 June 2018

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 to no set any further parameters in the /etc/krb5.conf file.

If your /etc/krb5.conf contains an include line it will not work, you Must remove this line.



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.