sssd.conf 5 File Formats and Conventions sssd.conf the configuration file for SSSD The file has an ini-style syntax and consists of sections and parameters. A section begins with the name of the section in square brackets and continues until the next section begins. An example of section with single and multi-valued parameters: [section] key = value key2 = value2,value3 The data types used are string (no quotes needed), integer and bool (with values of TRUE/FALSE). A line comment starts with a hash sign (#) or a semicolon (;) All sections can have an optional description parameter. Its function is only as a label for the section. sssd.conf must be a regular file, owned by root and only root may read from or write to the file. Individual pieces of SSSD functionality are provided by special SSSD services that are started and stopped together with SSSD. The services are managed by a special service frequently called monitor. The [sssd] section is used to configure the monitor as well as some other important options like the identity domains. config_file_version (integer) Indicates what is the syntax of the config file. SSSD 0.6.0 and later use version 2. services Comma separated list of services that are started when sssd itself starts. Supported services: nss, pam , sudo , autofs , ssh reconnection_retries (integer) Number of times services should attempt to reconnect in the event of a Data Provider crash or restart before they give up Default: 3 domains A domain is a database containing user information. SSSD can use more domains at the same time, but at least one must be configured or SSSD won't start. This parameter described the list of domains in the order you want them to be queried. re_expression (string) Regular expression that describes how to parse the string containing user name and domain into these components. Default: (?P<name>[^@]+)@?(?P<domain>[^@]*$) which translates to "the name is everything up to the @ sign, the domain everything after that" PLEASE NOTE: the support for non-unique named subpatterns is not available on all platforms (e.g. RHEL5 and SLES10). Only platforms with libpcre version 7 or higher can support non-unique named subpatterns. PLEASE NOTE ALSO: older version of libpcre only support the Python syntax (?P<name>) to label subpatterns. full_name_format (string) A printf 3 -compatible format that describes how to translate a (name, domain) tuple into a fully qualified name. Default: %1$s@%2$s. try_inotify (boolean) SSSD monitors the state of resolv.conf to identify when it needs to update its internal DNS resolver. By default, we will attempt to use inotify for this, and will fall back to polling resolv.conf every five seconds if inotify cannot be used. There are some limited situations where it is preferred that we should skip even trying to use inotify. In these rare cases, this option should be set to 'false' Default: true on platforms where inotify is supported. False on other platforms. Note: this option will have no effect on platforms where inotify is unavailable. On these platforms, polling will always be used. krb5_rcache_dir (string) Directory on the filesystem where SSSD should store Kerberos replay cache files. This option accepts a special value __LIBKRB5_DEFAULTS__ that will instruct SSSD to let libkrb5 decide the appropriate location for the replay cache. Default: Distribution-specific and specified at build-time. (__LIBKRB5_DEFAULTS__ if not configured) force_timeout (integer) If a service is not responding to ping checks (see the timeout option), it is first sent the SIGTERM signal that instructs it to quit gracefully. If the service does not terminate after force_timeout seconds, the monitor will forcibly shut it down by sending a SIGKILL signal. Default: 60 Settings that can be used to configure different services are described in this section. They should reside in the [$NAME] section, for example, for NSS service, the section would be [nss] These options can be used to configure any service. debug_level (integer) debug_timestamps (bool) Add a timestamp to the debug messages Default: true debug_microseconds (bool) Add microseconds to the timestamp in debug messages Default: false timeout (integer) Timeout in seconds between heartbeats for this service. This is used to ensure that the process is alive and capable of answering requests. Default: 10 reconnection_retries (integer) Number of times services should attempt to reconnect in the event of a Data Provider crash or restart before they give up Default: 3 fd_limit This option specifies the maximum number of file descriptors that may be opened at one time by this SSSD process. On systems where SSSD is granted the CAP_SYS_RESOURCE capability, this will be an absolute setting. On systems without this capability, the resulting value will be the lower value of this or the limits.conf "hard" limit. Default: 8192 (or limits.conf "hard" limit) These options can be used to configure the Name Service Switch (NSS) service. enum_cache_timeout (integer) How many seconds should nss_sss cache enumerations (requests for info about all users) Default: 120 entry_cache_nowait_percentage (integer) The entry cache can be set to automatically update entries in the background if they are requested beyond a percentage of the entry_cache_timeout value for the domain. For example, if the domain's entry_cache_timeout is set to 30s and entry_cache_nowait_percentage is set to 50 (percent), entries that come in after 15 seconds past the last cache update will be returned immediately, but the SSSD will go and update the cache on its own, so that future requests will not need to block waiting for a cache update. Valid values for this option are 0-99 and represent a percentage of the entry_cache_timeout for each domain. For performance reasons, this percentage will never reduce the nowait timeout to less than 10 seconds. (0 disables this feature) Default: 50 entry_negative_timeout (integer) Specifies for how many seconds nss_sss should cache negative cache hits (that is, queries for invalid database entries, like nonexistent ones) before asking the back end again. Default: 15 filter_users, filter_groups (string) Exclude certain users from being fetched from the sss NSS database. This is particularly useful for system accounts. This option can also be set per-domain or include fully-qualified names to filter only users from the particular domain. Default: root filter_users_in_groups (bool) If you want filtered user still be group members set this option to false. Default: true override_homedir (string) Override the user's home directory. You can either provide an absolute value or a template. In the template, the following sequences are substituted: %u login name %U UID number %d domain name %f fully qualified user name (user@domain) %% a literal '%' This option can also be set per-domain. fallback_homedir (string) Set a default template for a user's home directory if one is not specified explicitly by the domain's data provider. The available values for this option are the same as for override_homedir. Default: not set (no substitution for unset home directories) allowed_shells (string) Restrict user shell to one of the listed values. The order of evaluation is: 1. If the shell is present in /etc/shells, it is used. 2. If the shell is in the allowed_shells list but not in /etc/shells, use the value of the shell_fallback parameter. 3. If the shell is not in the allowed_shells list and not in /etc/shells, a nologin shell is used. An empty string for shell is passed as-is to libc. The /etc/shells is only read on SSSD start up, which means that a restart of the SSSD is required in case a new shell is installed. Default: Not set. The user shell is automatically used. vetoed_shells (string) Replace any instance of these shells with the shell_fallback shell_fallback (string) The default shell to use if an allowed shell is not installed on the machine. Default: /bin/sh default_shell The default shell to use if the provider does not return one during lookup. This option supersedes any other shell options if it takes effect. Default: not set (Return NULL if no shell is specified and rely on libc to substitute something sensible when necessary, usually /bin/sh) get_domains_timeout (int) Specifies time in seconds for which the list of subdomains will be considered valid. Default: 60 These options can be used to configure the Pluggable Authentication Module (PAM) service. offline_credentials_expiration (integer) If the authentication provider is offline, how long should we allow cached logins (in days since the last successful online login). Default: 0 (No limit) offline_failed_login_attempts (integer) If the authentication provider is offline, how many failed login attempts are allowed. Default: 0 (No limit) offline_failed_login_delay (integer) The time in minutes which has to pass after offline_failed_login_attempts has been reached before a new login attempt is possible. If set to 0 the user cannot authenticate offline if offline_failed_login_attempts has been reached. Only a successful online authentication can enable offline authentication again. Default: 5 pam_verbosity (integer) Controls what kind of messages are shown to the user during authentication. The higher the number to more messages are displayed. Currently sssd supports the following values: 0: do not show any message 1: show only important messages 2: show informational messages 3: show all messages and debug information Default: 1 pam_id_timeout (integer) For any PAM request while SSSD is online, the SSSD will attempt to immediately update the cached identity information for the user in order to ensure that authentication takes place with the latest information. A complete PAM conversation may perform multiple PAM requests, such as account management and session opening. This option controls (on a per-client-application basis) how long (in seconds) we can cache the identity information to avoid excessive round-trips to the identity provider. Default: 5 pam_pwd_expiration_warning (integer) Display a warning N days before the password expires. Please note that the backend server has to provide information about the expiration time of the password. If this information is missing, sssd cannot display a warning. If zero is set, then this filter is not applied, i.e. if the expiration warning was received from backend server, it will automatically be displayed. This setting can be overridden by setting pwd_expiration_warning for a particular domain. Default: 0 get_domains_timeout (int) Specifies time in seconds for which the list of subdomains will be considered valid. Default: 60 These options can be used to configure the sudo service. sudo_cache_timeout (integer) For any sudo request that comes while SSSD is online, the SSSD will attempt to update the cached rules in order to ensure that sudo has the latest ruleset. The user may, however, run a couple of sudo commands successively, which would trigger multiple LDAP requests. In order to speed up this use-case, the sudo service maintains an in-memory cache that would be used for performing fast replies. This option controls how long (in seconds) can the sudo service cache rules for a user. Default: 180 sudo_timed (bool) Whether or not to evaluate the sudoNotBefore and sudoNotAfter attributes that implement time-dependent sudoers entries. Default: false These options can be used to configure the autofs service. autofs_negative_timeout (integer) Specifies for how many seconds should the autofs responder negative cache hits (that is, queries for invalid map entries, like nonexistent ones) before asking the back end again. Default: 15 These options can be used to configure the SSH service. ssh_hash_known_hosts (bool) Whether or not to hash host names and addresses in the managed known_hosts file. Default: true These configuration options can be present in a domain configuration section, that is, in a section called [domain/NAME] min_id,max_id (integer) UID and GID limits for the domain. If a domain contains an entry that is outside these limits, it is ignored. For users, this affects the primary GID limit. The user will not be returned to NSS if either the UID or the primary GID is outside the range. For non-primary group memberships, those that are in range will be reported as expected. Default: 1 for min_id, 0 (no limit) for max_id enumerate (bool) Determines if a domain can be enumerated. This parameter can have one of the following values: TRUE = Users and groups are enumerated FALSE = No enumerations for this domain Default: FALSE Note: Enabling enumeration has a moderate performance impact on SSSD while enumeration is running. It may take up to several minutes after SSSD startup to fully complete enumerations. During this time, individual requests for information will go directly to LDAP, though it may be slow, due to the heavy enumeration processing. While the first enumeration is running, requests for the complete user or group lists may return no results until it completes. Further, enabling enumeration may increase the time necessary to detect network disconnection, as longer timeouts are required to ensure that enumeration lookups are completed successfully. For more information, refer to the man pages for the specific id_provider in use. entry_cache_timeout (integer) How many seconds should nss_sss consider entries valid before asking the backend again Default: 5400 entry_cache_user_timeout (integer) How many seconds should nss_sss consider user entries valid before asking the backend again Default: entry_cache_timeout entry_cache_group_timeout (integer) How many seconds should nss_sss consider group entries valid before asking the backend again Default: entry_cache_timeout entry_cache_netgroup_timeout (integer) How many seconds should nss_sss consider netgroup entries valid before asking the backend again Default: entry_cache_timeout entry_cache_service_timeout (integer) How many seconds should nss_sss consider service entries valid before asking the backend again Default: entry_cache_timeout cache_credentials (bool) Determines if user credentials are also cached in the local LDB cache User credentials are stored in a SHA512 hash, not in plaintext Default: FALSE account_cache_expiration (integer) Number of days entries are left in cache after last successful login before being removed during a cleanup of the cache. 0 means keep forever. The value of this parameter must be greater than or equal to offline_credentials_expiration. Default: 0 (unlimited) pwd_expiration_warning (integer) Display a warning N days before the password expires. If zero is set, then this filter is not applied, i.e. if the expiration warning was received from backend server, it will automatically be displayed. Please note that the backend server has to provide information about the expiration time of the password. If this information is missing, sssd cannot display a warning. Also an auth provider has to be configured for the backend. Default: 7 (Kerberos), 0 (LDAP) id_provider (string) The Data Provider identity backend to use for this domain. Supported backends: proxy: Support a legacy NSS provider local: SSSD internal local provider ldap: LDAP provider use_fully_qualified_names (bool) Use the full name and domain (as formatted by the domain's full_name_format) as the user's login name reported to NSS. If set to TRUE, all requests to this domain must use fully qualified names. For example, if used in LOCAL domain that contains a "test" user, getent passwd test wouldn't find the user while getent passwd test@LOCAL would. Default: FALSE auth_provider (string) The authentication provider used for the domain. Supported auth providers are: ldap for native LDAP authentication. See sssd-ldap 5 for more information on configuring LDAP. krb5 for Kerberos authentication. See sssd-krb5 5 for more information on configuring Kerberos. proxy for relaying authentication to some other PAM target. none disables authentication explicitly. Default: id_provider is used if it is set and can handle authentication requests. access_provider (string) The access control provider used for the domain. There are two built-in access providers (in addition to any included in installed backends) Internal special providers are: permit always allow access. It's the only permitted access provider for a local domain. deny always deny access. simple access control based on access or deny lists. See sssd-simple 5 for more information on configuring the simple access module. Default: permit chpass_provider (string) The provider which should handle change password operations for the domain. Supported change password providers are: ipa to change a password stored in an IPA server. See sssd-ipa 5 for more information on configuring IPA. ldap to change a password stored in a LDAP server. See sssd-ldap 5 for more information on configuring LDAP. krb5 to change the Kerberos password. See sssd-krb5 5 for more information on configuring Kerberos. proxy for relaying password changes to some other PAM target. none disallows password changes explicitly. Default: auth_provider is used if it is set and can handle change password requests. sudo_provider (string) The SUDO provider used for the domain. Supported SUDO providers are: ldap for rules stored in LDAP. See sssd-ldap 5 for more information on configuring LDAP. none disables SUDO explicitly. Default: The value of id_provider is used if it is set. session_provider (string) The provider which should handle loading of session settings. Supported session providers are: ipa to load session settings from an IPA server. See sssd-ipa 5 for more information on configuring IPA. none disallows fetching session settings explicitly. Default: id_provider is used if it is set and can handle session loading requests. subdomains_provider (string) The provider which should handle fetching of subdomains. This value should be always the same as id_provider. Supported subdomain providers are: ipa to load a list of subdomains from an IPA server. See sssd-ipa 5 for more information on configuring IPA. none disallows fetching subdomains explicitly. Default: none autofs_provider (string) The autofs provider used for the domain. Supported autofs providers are: ldap to load maps stored in LDAP. See sssd-ldap 5 for more information on configuring LDAP. ipa to load maps stored in an IPA server. See sssd-ipa 5 for more information on configuring IPA. none disables autofs explicitly. Default: The value of id_provider is used if it is set. hostid_provider (string) The provider used for retrieving host identity information. Supported hostid providers are: ipa to load host identity stored in an IPA server. See sssd-ipa 5 for more information on configuring IPA. none disables hostid explicitly. Default: The value of id_provider is used if it is set. lookup_family_order (string) Provides the ability to select preferred address family to use when performing DNS lookups. Supported values: ipv4_first: Try looking up IPv4 address, if that fails, try IPv6 ipv4_only: Only attempt to resolve hostnames to IPv4 addresses. ipv6_first: Try looking up IPv6 address, if that fails, try IPv4 ipv6_only: Only attempt to resolve hostnames to IPv6 addresses. Default: ipv4_first dns_resolver_timeout (integer) Defines the amount of time (in seconds) to wait for a reply from the DNS resolver before assuming that it is unreachable. If this timeout is reached, the domain will continue to operate in offline mode. Default: 5 dns_discovery_domain (string) If service discovery is used in the back end, specifies the domain part of the service discovery DNS query. Default: Use the domain part of machine's hostname override_gid (integer) Override the primary GID value with the one specified. case_sensitive (boolean) Treat user and group names as case sensitive. At the moment, this option is not supported in the local provider. Default: True proxy_fast_alias (boolean) When a user or group is looked up by name in the proxy provider, a second lookup by ID is performed to "canonicalize" the name in case the requested name was an alias. Setting this option to true would cause the SSSD to perform the ID lookup from cache for performance reasons. Default: false subdomain_homedir (string) Use this homedir as default value for all subdomains within this domain. See override_homedir for info about possible values. The value can be overridden by override_homedir option. Options valid for proxy domains. proxy_pam_target (string) The proxy target PAM proxies to. Default: not set by default, you have to take an existing pam configuration or create a new one and add the service name here. proxy_lib_name (string) The name of the NSS library to use in proxy domains. The NSS functions searched for in the library are in the form of _nss_$(libName)_$(function), for example _nss_files_getpwent. This section contains settings for domain that stores users and groups in SSSD native database, that is, a domain that uses id_provider=local. default_shell (string) The default shell for users created with SSSD userspace tools. Default: /bin/bash base_directory (string) The tools append the login name to base_directory and use that as the home directory. Default: /home create_homedir (bool) Indicate if a home directory should be created by default for new users. Can be overridden on command line. Default: TRUE remove_homedir (bool) Indicate if a home directory should be removed by default for deleted users. Can be overridden on command line. Default: TRUE homedir_umask (integer) Used by sss_useradd 8 to specify the default permissions on a newly created home directory. Default: 077 skel_dir (string) The skeleton directory, which contains files and directories to be copied in the user's home directory, when the home directory is created by sss_useradd 8 Default: /etc/skel mail_dir (string) The mail spool directory. This is needed to manipulate the mailbox when its corresponding user account is modified or deleted. If not specified, a default value is used. Default: /var/mail userdel_cmd (string) The command that is run after a user is removed. The command us passed the username of the user being removed as the first and only parameter. The return code of the command is not taken into account. Default: None, no command is run The following example shows a typical SSSD config. It does not describe configuration of the domains themselves - refer to documentation on configuring domains for more details. [sssd] domains = LDAP services = nss, pam config_file_version = 2 [nss] filter_groups = root filter_users = root [pam] [domain/LDAP] id_provider = ldap ldap_uri = ldap://ldap.example.com ldap_search_base = dc=example,dc=com auth_provider = krb5 krb5_server = kerberos.example.com krb5_realm = EXAMPLE.COM cache_credentials = true min_id = 10000 max_id = 20000 enumerate = False sssd-ldap5 , sssd-krb55 , sss_groupadd8 , sss_groupdel8 , sss_groupmod8 , sss_useradd8 , sss_userdel8 , sss_usermod8 , pam_sss8 .