man/auto.master.5.in

.\" t
.TH AUTO.MASTER 5 "11 Apr 2006"
.SH NAME
auto.master \- Master Map for automounter consulted by autofs
.SH "DESCRIPTION"
The
.B auto.master
map is consulted to set up automount managed mount points when the
.nh
.BR autofs (8)
.hy
script is invoked or the
.nh
.BR automount (8)
.hy
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.
.P
The default location of the master map is
.nh
.B @@autofsmapdir@@/auto.master
.hy
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
.nh
.B "MASTER_MAP_NAME"
.hy
configuration variable in
.nh
.B @@autofsconfdir@@/autofs.
.hy
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.
.P
Access to mounts in maps is governed by a key.
.P
For direct maps the mount point is always specified as:
.P
.BR /-
.P
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.
.P
For indirect maps access is by using the path scheme:
.P
.BR /mount-point/key
.P
where
.I mount-point
is one of the entries listed in the master map. The
.I key
is a single directory component and is matched against entries in the
map given in the entry (See
.BR autofs (5)).
.P
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:
.P
.BR + [ maptype [, format ]:] map\  [ options ]
.P
and 
.BR 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
.BR automount (8).
.TP
.B 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.
.SH "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.
.P
The format of a master map entry is:
.TP
.BR mount-point\  [ map-type [, format ]:] map\  [ options ]
.TP
.B mount-point
Base location for the \fBautofs\fP filesystem to be mounted.  For
indirect maps this directory will be created (as with \fBmkdir \-p\fP)
and is removed when the \fBautofs\fP filesystem is umounted.
.TP
.B map-type
Type of map used for this mount point.  The following are
valid map types:
.RS
.TP
.B file
The map is a regular text file.
.TP
.B 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.
.TP
.B yp
The map is a NIS (YP) database.
.TP
.B nisplus
The map is a NIS+ database.
.TP
.B hesiod
The map is a hesiod database whose
.B filsys
entries are used for maps.
.TP
.B ldap \fPor\fB ldaps
The map is stored in an LDAP directory. If \fBldaps\fP is used the
appropriate certificate must be configured in the LDAP client.
.TP
.B multi
This map type allows the specification of multiple maps separated
by "--". These maps are searched in order to resolve key lookups.
.TP
.B dir
This map type can be used at
.BR +
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.
.RE
.TP
.B format
.br
Format of the map data; currently the formats recognized are \fBsun\fP,
which is a subset of the Sun automounter map format, \fBhesiod\fP, for
hesiod filesys entries and \fBamd\fP for amd formated map entries.
If the format is left unspecified, it defaults to \fBsun\fP for all map
types except \fBhesiod\fP unless it is a top level \fBamd\fP mount that
has a configuration entry for the mount point path, in which case the
format used is \fBamd\fP.
.TP
.B map
.br
Name of the map to use.  This is an absolute UNIX pathname
for maps of types \fBfile\fP, \fBdir\fP, or \fBprogram\fP, and the name of a database
in the case for maps of type \fByp\fP, \fBnisplus\fP, or \fBhesiod\fP or
the \fBdn\fP of an LDAP entry for maps of type \fBldap\fP.
.TP
.B options
.br
Any remaining command line arguments without leading dashes (\-) are
taken as options (\fI\-o\fP) to \fBmount\fP.  Arguments with leading
dashes are considered options for the maps and are passed to automount (8).
.sp
The \fBsun\fP format supports the following options:
.RS
.TP
.I "\-Dvariable=value"
Replace \fIvariable\fP with \fIvalue\fP in map substitutions.
.TP
.I "\-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.
.TP
.I "[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. This option does the same as the deprecated --ghost option, the
browse option is preferred because it is used by other autofs implementations.
.TP
.I "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. Preventing bind mounts of NFS
file systems can no longer be done by using the "port=" option, the
nobind option must be used instead.
.TP
.I "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.
.TP
.I slave \fPor\fI private
This option allows mount propagation of bind mounts to be set to
either \fIslave\fP or \fIprivate\fP. This option may be needed when using
multi-mounts that have bind mounts that bind to a file system that is
propagation shared. This is becuase the bind mount will have the same
properties as its target which causes problems for offset mounts. When
this happens an unwanted offset mount is propagated back to the target
file system resulting in a deadlock when attempting to access the offset.
This option is a an autofs pseudo mount option that can be used in the
master map only. By default bind mounts will inherit the mount propagation
of the target file system.
.TP
.I "\-r, \-\-random-multimount-selection"
Enables the use of random 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.
.TP
.I "\-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.
.TP
.I "\-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.
.TP
.I "\-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.
.TP
.I "\-\-mode <octal_mode>"
Set the directory mode for the base location of the \fBautofs\fP mount point.
If this option is given, \fBautofs\fP will chmod that directory with this
mode.
.SH 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.
.P
For example, with an entry in the master map of
.nh
.B /net  \-hosts
.hy
accessing /net/myserver will mount exports from myserver on directories below
/net/myserver.
.P
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.
.SH LDAP MAPS
If the map type \fBldap\fP is specified the mapname is of the form
\fB[//servername/]dn\fP, where the optional \fBservername\fP is
the name of the LDAP server to query, and \fBdn\fP is the Distinguished
Name of a subtree to search for map entries.
The old style
.nh
.B ldap:servername:mapname
.hy
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.
.P
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.
.P
There are three common schemas in use:
.TP
.I nisMap
.br
Entries in the \fBnisMap\fP schema are \fBnisObject\fP objects in
the specified subtree, where the \fBcn\fP attribute is the key
(the wildcard key is "/"), and the \fBnisMapEntry\fP attribute
contains the information used by the automounter.
.TP
.I automountMap
The \fBautomountMap\fP schema has two variations that differ in the attribute
used for the map key. Entries in the automountMap schema are \fBautomount\fP
objects in the specified subtree, where the \fBcn\fP or \fBautomountKey\fP
attribute (depending on local usage) is the key (the wildcard key is "/"),
and the \fBautomountInformation\fP attribute contains the information used
by the automounter. Note that the \fBcn\fP attribute is case insensitive.
.P
The object classes and attributes used for accessing automount maps in
LDAP can be changed by setting entries in the autofs configuration
located in
.nh
.BR @@autofsconfdir@@/autofs.conf .
.hy
.TP
.B 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.
.TP
For \fBamd\fP format maps a different schema is used:
.TP
.I amdMap
.br
The \fBamdmap\fP schema contains attributes \fBamdmapName\fP, \fBamdmapKey\fP
and \fBamdmapValue\fP where \fBamdmapName\fP contains the name of the containing
map, \fBamdmapKey\fP contains the map key and \fBamdmapValue\fP contains the
map entry.
.SH 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
.nh
.BR @@autofsmapdir@@/autofs_ldap_auth.conf .
.hy
.P
If this file exists it will be used to establish whether TLS or authentication
should be used.
.P
An example of this file is:
.sp
.RS +.2i
.ta 1.0i
.nf
<?xml version="1.0" ?>
<autofs_ldap_sasl_conf
        usetls="yes"
        tlsrequired="no"
        authrequired="no"
        authtype="DIGEST-MD5"
        user="xyz"
        secret="abc"
/>
.fi
.RE
.sp
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.
.P
In OpenLDAP these may be configured in the \fBldap.conf\fP 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.
.P
See
.B autofs_ldap_auth.conf (5)
for more information.
.SH EXAMPLE
.sp
.RS +.2i
.ta 1.0i
.nf
/-	auto.data
/home	/etc/auto.home
/mnt	yp:mnt.map
.fi
.RE
.sp
This will generate two mountpoints for 
.IR /home
and
.IR /mnt
and install direct mount triggers for each entry in the direct mount map
.IR auto.data .
All accesses to
.I /home
will lead to the consultation of the map in
.IR /etc/auto.home
and all accesses to
.I /mnt
will consult the NIS map
.IR mnt.map .
All accesses to paths in the map
.IR 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
.IR auto.data .
.SH "SEE ALSO"
.BR automount (8),
.BR autofs (5),
.BR autofs (8),
.BR autofs.conf (5),
.BR autofs_ldap_auth.conf (5).
.SH 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> .