SSSD-SUDO(5) File Formats and Conventions SSSD-SUDO(5)NAMEsssd-sudo - Configuring sudo with the SSSD back end
DESCRIPTION
This manual page describes how to configure sudo(8) to work with
sssd(8) and how SSSD caches sudo rules.
CONFIGURING SUDO TO COOPERATE WITH SSSD
To enable SSSD as a source for sudo rules, add sss to the sudoers entry
in nsswitch.conf(5).
For example, to configure sudo to first lookup rules in the standard
sudoers(5) file (which should contain rules that apply to local users)
and then in SSSD, the nsswitch.conf file should contain the following
line:
sudoers: files sss
More information about configuring the sudoers search order from the
nsswitch.conf file as well as information about the LDAP schema that is
used to store sudo rules in the directory can be found in
sudoers.ldap(5).
CONFIGURING SSSD TO FETCH SUDO RULES
The following example shows how to configure SSSD to download sudo
rules from an LDAP server.
[sssd]
config_file_version = 2
services = nss, pam, sudo
domains = EXAMPLE
[domain/EXAMPLE]
id_provider = ldap
sudo_provider = ldap
ldap_uri = ldap://example.com
ldap_sudo_search_base = ou=sudoers,dc=example,dc=com
The following example illustrates setting up SSSD to download sudo
rules from an IPA server. It is necessary to use the LDAP provider and
set appropriate connection parameters to authenticate correctly against
the IPA server, because SSSD does not have native support of IPA
provider for sudo yet.
[sssd]
config_file_version = 2
services = nss, pam, sudo
domains = EXAMPLE
[domain/EXAMPLE]
id_provider = ipa
ipa_domain = example.com
ipa_server = ipa.example.com
ldap_tls_cacert = /etc/ipa/ca.crt
sudo_provider = ldap
ldap_uri = ldap://ipa.example.com
ldap_sudo_search_base = ou=sudoers,dc=example,dc=com
ldap_sasl_mech = GSSAPI
ldap_sasl_authid = host/hostname.example.com
ldap_sasl_realm = EXAMPLE.COM
krb5_server = ipa.example.com
THE SUDO RULE CACHING MECHANISM
The biggest challenge, when developing sudo support in SSSD, was to
ensure that running sudo with SSSD as the data source provides the same
user experience and is as fast as sudo but keeps providing the most
current set of rules as possible. To satisfy these requirements, SSSD
uses three kinds of updates. They are referred to as full refresh,
smart refresh and rules refresh.
The smart refresh periodically downloads rules that are new or were
modified after the last update. Its primary goal is to keep the
database growing by fetching only small increments that do not generate
large amounts of network traffic.
The full refresh simply deletes all sudo rules stored in the cache and
replaces them with all rules that are stored on the server. This is
used to keep the cache consistent by removing every rule which was
deleted from the server. However, full refresh may produce a lot of
traffic and thus it should be run only occasionally depending on the
size and stability of the sudo rules.
The rules refresh ensures that we do not grant the user more permission
than defined. It is triggered each time the user runs sudo. Rules
refresh will find all rules that apply to this user, check their
expiration time and redownload them if expired. In the case that any of
these rules are missing on the server, the SSSD will do an out of band
full refresh because more rules (that apply to other users) may have
been deleted.
If enabled, SSSD will store only rules that can be applied to this
machine. This means rules that contain one of the following values in
sudoHost attribute:
· keyword ALL
· wildcard
· netgroup (in the form "+netgroup")
· hostname or fully qualified domain name of this machine
· one of the IP addresses of this machine
· one of the IP addresses of the network (in the form "address/mask")
There are many configuration options that can be used to adjust the
behavior. Please refer to "ldap_sudo_*" in sssd-ldap(5) and "sudo_*" in
sssd.conf(5).
SEE ALSOsssd(8), sssd.conf(5), sssd-ldap(5), sssd-krb5(5), sssd-simple(5),
sssd-ipa(5), sssd-ad(5), sssd-sudo(5),sss_cache(8), sss_debuglevel(8),
sss_groupadd(8), sss_groupdel(8), sss_groupshow(8), sss_groupmod(8),
sss_useradd(8), sss_userdel(8), sss_usermod(8), sss_obfuscate(8),
sss_seed(8), sssd_krb5_locator_plugin(8), sss_ssh_authorizedkeys(8),
sss_ssh_knowhostsproxy(8),pam_sss(8).
AUTHORS
The SSSD upstream - http://fedorahosted.org/sssd
SSSD 04/23/2013 SSSD-SUDO(5)
