auto.master(5)
NAME
auto.master - Master Map for automounter
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. 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).
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:
file The map is a regular text file.
program
The map is an executable program, which is passed a key
on the command line and returns an entry (everything
besides the key) on stdout if successful. Optinally, the
keyword exec may be used as a synonym for program to
avoid confusion with amd formated maps mount type
program.
yp The map is a NIS (YP) database.
nisplus
The map is a NIS+ database.
hesiod The map is a hesiod database whose filsys entries are
used for maps.
ldap or ldaps
The map is stored in an LDAP directory. If ldaps is used
the appropriate certificate must be configured in the
LDAP client.
multi This map type allows the specification of multiple maps
separated by "--". These maps are searched in order to
resolve key lookups.
dir This map type can be used at + master map including
notation. The contents of files under given directory are
included to the master map. The name of file to be
included must be ended with ".autofs". A file will be
ignored if its name is not ended with the suffix. In
addition a dot file, a file which name is started with
"." is also ignored.
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 formated 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:
-Dvariable=value
Replace variable with value in map substitutions.
-strict
Treat errors when mounting file systems as fatal. This is
important when multiple file systems should be mounted
(`multimounts'). If this option is given, no file system
is mounted at all if at least one file system can't be
mounted.
[no]browse
This is an autofs specific option that is a pseudo mount
option and so is given without a leading dash. Use of the
browse option pre-creates mount point directories for
indirect mount maps so the map keys can be seen in a
directory listing without being mounted. Use of this
option can cause performance problem if the indirect map
is large so it should be used with caution. The internal
program default is to enable browse mode for indirect
mounts but the default installed configuration overrides
this by setting BROWSE_MODE to "no" because of the
potential performance problem.
nobind This is an autofs specific option that is a pseudo mount
option and so is given without a leading dash. It may be
used either in the master map entry (so it effects all
the map entries) or with individual map entries to
prevent bind mounting of local NFS filesystems. For
direct mount maps the option is only effective if
specified on the first direct map entry and is applied to
all direct mount maps in the master map. It is ignored if
given on subsequent direct map entries. It may be used on
individual map entries of both types. Bind mounting of
NFS file systems can also be prevented for specific map
entrys by adding the "port=" mount option to the entries.
symlink
This option makes bind mounting use a symlink instead of
an actual bind mount. It is an autofs specific option
that is a pseudo mount option and so is given without a
leading dash. It may be used with indirect map entries
only, either in the master map (so it effects all map
entries) or with individual map entries. The option is
ignored for direct mounts and non-root offest mount
entries.
-r, --random-multimount-selection
Enables the use of ramdom selection when choosing a host
from a list of replicated servers. This option is applied
to this mount only, overriding the global setting that
may be specified on the command line.
-w, --use-weight-only
Use only specified weights for server selection where
more than one server is specified in the map entry. If no
server weights are given then each available server will
be tried in the order listed, within proximity.
-t, --timeout <seconds>
Set the expire timeout for map entries. This option can
be used to override the global default given either on
the command line or in the configuration.
-n, --negative-timeout <seconds>
Set the timeout for caching failed key lookups. This
option can be used to override the global default given
either on the command line or in the configuration.
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,intr" options unless overridden by explicily specifying the "suid", "dev" or "nointr" options in the master map 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 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.
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 <[email protected]>, for the Debian GNU/Linux system. Edited by <[email protected]> and Ian Kent <[email protected]> . 11 Apr 2006 AUTO.MASTER(5)
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