NAME¶

auto.master - Master Map for automounter consulted by autofs

DESCRIPTION¶

The auto.master map is consulted to set up automount managed mount points when the autofs(8) script is invoked or the automount(8) program is run. Each line describes a mount point and refers to an autofs map describing file systems to be mounted under the mount point.

The default location of the master map is /etc/auto.master but an alternate name may be given on the command line when running the automounter and the default master map may changed by setting the MASTER_MAP_NAME configuration variable in /etc/default/autofs. If the master map name has no path then the system Name Service Switch configuration will be consulted and each of the sources searched in line with the rules given in the Name Service Switch configuration.

Access to mounts in maps is governed by a key.

For direct maps the mount point is always specified as:

/-

and the key used within the direct map is the full path to the mount point. The direct map may have multiple entries in the master map.

For indirect maps access is by using the path scheme:

/mount-point/key

where mount-point is one of the entries listed in the master map. The key is a single directory component and is matched against entries in the map given in the entry (See autofs(5)).

Additionally, a map may be included from its source as if it were itself present in the master map by including a line of the form:

+[maptype[,format]:]map [options]

and automount(8) will process the map according to the specification described below for map entries. Plus map inclusion is only permitted in file map sources. Indirect map entries must be unique in the master map so second and subsequent entries for an indirect mount point are ignored by automount(8).

NOTE:

autofs currently does not collapse multiple slashes in paths, so it is important to ensure paths used in maps are correct. If unnecessary multiple slashes are present in a path it can lead to unexpected failures such as an inability to expire automounts. An exception to this is a trailing slash at the end of the automount point path in the master map which will be removed if present.

FORMAT¶

Master map entries have three fields separated by an arbitrary number of spaces or tabs. Lines beginning with # are comments. The first field is the mount point described above and the second field is the name of the map to be consulted for the mount point followed by the third field which contains options to be applied to all entries in the map.

The format of a master map entry is:

mount-point [map-type[,format]:]map [options]

mount-point

Base location for the autofs filesystem to be mounted. For indirect maps this directory will be created (as with mkdir -p) and is removed when the autofs filesystem is umounted.

map-type

Type of map used for this mount point. The following are valid map types:

format

Format of the map data; currently the formats recognized are sun, which is a subset of the Sun automounter map format, hesiod, for hesiod filesys entries and amd for amd formatted map entries. If the format is left unspecified, it defaults to sun for all map types except hesiod unless it is a top level amd mount that has a configuration entry for the mount point path, in which case the format used is amd.

map

Name of the map to use. This is an absolute UNIX pathname for maps of types file, dir, or program, and the name of a database in the case for maps of type yp, nisplus, or hesiod or the dn of an LDAP entry for maps of type ldap.

options

Any remaining command line arguments without leading dashes (-) are taken as options (-o) to mount. Arguments with leading dashes are considered options for the maps and are passed to automount (8).

The sun format supports the following options:

BUILTIN MAP -hosts¶

If "-hosts" is given as the map then accessing a key under the mount point which corresponds to a hostname will allow access to the exports of that host. The hosts map cannot be dynamically updated and requires a HUP signal to be sent to the daemon for it to check hosts for an update. Due to possible hierarchic dependencies within a mount tree, it might not be completely updated during the HUP signal processing.

For example, with an entry in the master map of /net -hosts accessing /net/myserver will mount exports from myserver on directories below /net/myserver.

NOTE: mounts done from a hosts map will be mounted with the "nosuid,nodev" options unless overridden by explicitly specifying the "suid", "dev" options in the master map entry.

BUILTIN MAP -null¶

If "-null" is given as the map it is used to tell automount(8) to ignore a subsequent master map entry with the given path.

It can be used for paths that appear in the master map or in direct mount maps (but not in direct mount maps themselves) or as a key in an indirect mount map.

An indirect mount map key can be nulled. If so the map key is ignored and does not result in a mount attempt (essentially the key lookup is abandoned early on).

An indirect mount map top level mount point path can be nulled. If so no mounts from the nulled mount are performed (essentially it isn't mounted).

Direct mount map path entries can be nulled. Since they must be present at startup they are (notionally) part of the master map so direct mount paths that use the -null map may be used in the master map to ignore subsequent direct mount map entries.

A nulled master map entry path will ignore a single subsequent matching entry. Any matching entry following that will be treated as it normally would be. An example use of this is allowing local master map entries to override remote ones.

NOTE: If a duplicate master map entry path is seen (excluding paths of null entries) it will be ignored and noted in the log, that is the first encountered master map entry is used unless there is a corresponding null entry.

LDAP MAPS¶

If the map type ldap is specified the mapname is of the form [//servername/]dn, where the optional servername is the name of the LDAP server to query, and dn is the Distinguished Name of a subtree to search for map entries. The old style ldap:servername:mapname is also understood. Alternatively, the type can be obtained from the Name Service Switch configuration, in which case the map name alone must be given.

If no schema is set in the autofs configuration then autofs will check each of the commonly used schema for a valid entry and if one is found it will be used for subsequent lookups.

There are three common schemas in use:

nisMap

Entries in the nisMap schema are nisObject objects in the specified subtree, where the cn attribute is the key (the wildcard key is "/"), and the nisMapEntry attribute contains the information used by the automounter.

automountMap

The automountMap schema has two variations that differ in the attribute used for the map key. Entries in the automountMap schema are automount objects in the specified subtree, where the cn or automountKey attribute (depending on local usage) is the key (the wildcard key is "/"), and the automountInformation attribute contains the information used by the automounter. Note that the cn attribute is case insensitive.

The object classes and attributes used for accessing automount maps in LDAP can be changed by setting entries in the autofs configuration located in /etc/default/autofs.conf.

NOTE:

If a schema is given in the configuration then all the schema configuration values must be set, any partial schema specification will be ignored.

For amd format maps a different schema is used:

amdMap

The amdmap schema contains attributes amdmapName, amdmapKey and amdmapValue where amdmapName contains the name of the containing map, amdmapKey contains the map key and amdmapValue contains the map entry.

LDAP AUTHENTICATION, ENCRYPTED AND CERTIFIED CONNECTIONS¶

LDAP authenticated binds, TLS encrypted connections and certification may be used by setting appropriate values in the autofs authentication configuration file and configuring the LDAP client with appropriate settings. The default location of this file is /etc/autofs_ldap_auth.conf.

If this file exists it will be used to establish whether TLS or authentication should be used.

An example of this file is:

<?xml version="1.0" ?>
<autofs_ldap_sasl_conf


        usetls="yes"


        tlsrequired="no"


        authrequired="no"


        authtype="DIGEST-MD5"


        user="xyz"


        secret="abc"
/>

If TLS encryption is to be used the location of the Certificate Authority certificate must be set within the LDAP client configuration in order to validate the server certificate. If, in addition, a certified connection is to be used then the client certificate and private key file locations must also be configured within the LDAP client.

In OpenLDAP these may be configured in the ldap.conf file or in the per-user configuration. For example, it may be sensible to use the system wide configuration for the location of the Certificate Authority certificate and set the location of the client certificate and private key in the per-user configuration. The location of these files and the configuration entry requirements is system dependent so the documentation for your installation will need to be consulted to get further information.

See autofs_ldap_auth.conf (5) for more information.

EXAMPLE¶

/-	auto.data
/home	/etc/auto.home
/mnt	yp:mnt.map

This will generate two mountpoints for /home and /mnt and install direct mount triggers for each entry in the direct mount map auto.data. All accesses to /home will lead to the consultation of the map in /etc/auto.home and all accesses to /mnt will consult the NIS map mnt.map. All accesses to paths in the map auto.data will trigger mounts when they are accessed and the Name Service Switch configuration will be used to locate the source of the map auto.data.

To avoid making edits to /etc/auto.master, /etc/auto.master.d may be used. Files in that directory must have a ".autofs" suffix, e.g. /etc/auto.master.d/extra.autofs. Such files contain lines of the same format as the auto.master file, e.g.

/foo    /etc/auto.foo
/baz    yp:baz.map

SEE ALSO¶

automount(8), autofs(5), autofs(8), autofs.conf(5), autofs_ldap_auth.conf(5).

AUTHOR¶

This manual page was written by Christoph Lameter <chris@waterf.org>, for the Debian GNU/Linux system. Edited by <hpa@transmeta.com> and Ian Kent <raven@themaw.net> .