AUTO_MASTER(5) | File Formats Manual | AUTO_MASTER(5) |
auto_master
—
auto_master
configuration file, which assigns file
system paths to map names, and maps, which contain actual mount information.
The auto_master
configuration file is used by the
automount(8) command. Map
files are read by the
automountd(8) daemon.
auto_master
file consists of lines with two or three
entries separated by whitespace and terminated by a newline character:
mountpoint
map_name
[-
options
]
mountpoint is either a fully specified path, or /-. When mountpoint is a full path, map_name must reference an indirect map. Otherwise, map_name must reference a direct map. See MAP SYNTAX below.
map_name specifies map to use. If
map_name begins with -
, it
specifies a special map. See MAP SYNTAX
below. If map_name is not a fully specified path (it
does not start with /
),
automountd(8) will search
for that name in /etc. Otherwise it will use the
path as given. If the file indicated by map_name is
executable, automountd(8)
will assume it is an executable map. See
MAP SYNTAX below. Otherwise, the file
is opened and the contents parsed.
[-
options] is an
optional field that starts with -
and can contain
generic file system mount options.
The following example specifies that the /etc/auto_example indirect map will be mounted on /example.
/example auto_example
key [-
options ] [mountpoint [-
options ] ] location [... ]
In most cases, it can be simplified to:
key
[-
options
]
location
key is the path component used by
automountd(8) to find the
right map entry to use. It is also used to form the final mountpoint. A
wildcard (‘*
’) can be used for the
key. It matches every directory that does not match other keys. Those
directories will not be visible to the user until accessed.
The options field, if present, must begin
with -
. When mounting the file system, options
supplied to auto_master
and options specified in the
map entry are concatenated together. The special option
fstype
is used to specify file system type. It is
not passed to the mount program as an option. Instead, it is passed as an
argument to mount -t
. The default
fstype
is
‘nfs
’. The special option
nobrowse
is used to disable creation of top-level
directories for special and executable maps.
The optional mountpoint field is used to specify multiple mount points for a single key.
The location field specifies the file system
to be mounted. Ampersands (‘&
’) in
the location field are replaced with the value of
key. This is typically used with wildcards, like:
* 192.168.1.1:/share/&
The location field may contain references to variables, like:
sys 192.168.1.1:/sys/${OSNAME}
Defined variables are:
ARCH
uname -p
.CPU
ARCH
.HOST
uname -n
.OSNAME
uname -s
.OSREL
uname -r
.OSVERS
uname -v
.Additional variables can be defined with the
-D
option of
automount(8) and
automountd(8).
To pass a location that begins with /,
prefix it with a colon. For example, :/dev/cd0
.
This example, when put into
/etc/auto_example, and with
auto_master
referring to the map as described above,
specifies that the NFS share
192.168.1.1:/share/example/x
will be mounted on
/example/x/ when any process attempts to access that
mountpoint, with intr
and
nfsv4
mount options, described in
mount_nfs(8):
x -intr,nfsv4 192.168.1.1:/share/example/x
Automatically mount an SMB share on access, as a guest user, without prompting for a password:
share -fstype=smbfs,-N ://@server/share
Automatically mount the CD drive on access:
cd -fstype=cd9660 :/dev/cd0
-
. Supported
special maps are:
-hosts
-media
-noauto
-null
It is possible to add custom special maps by adding them, as executable maps named special_foo, to the /etc/autofs/ directory.
auto_master
has the execute
bit set, automountd(8) will
execute it and parse the standard output instead of parsing the file contents.
When called without command line arguments, the executable is expected to
output a list of available map keys separated by newline characters.
Otherwise, the executable will be called with a key name as a command line
argument. Output from the executable is expected to be the entry for that key,
not including the key itself.
auto_master
by entries
with a fully qualified path as a mount point, and must contain only relative
paths as keys. Direct maps are referred to in
auto_master
by entries with /-
as the mountpoint, and must contain only fully qualified paths as keys. For
indirect maps, the final mount point is determined by concatenating the
auto_master
mountpoint with the map entry key and
optional map entry mountpoint. For direct maps, the final mount point is
determined by concatenating the map entry key with the optional map entry
mountpoint.
The example above could be rewritten using direct map, by placing
this in auto_master
:
/- auto_example
and this in the /etc/auto_example map file:
/example/x -intr,nfsv4 192.168.1.1:/share/example/x /example/share -fstype=smbfs,-N ://@server/share /example/cd -fstype=cd9660 :/dev/cd0
auto_master
and maps may contain entries consisting
of a plus sign and map name:
+auto_master
Those entries cause automountd(8) daemon to retrieve the named map from directory services (like LDAP) and include it where the entry was.
If the file containing the map referenced in
auto_master
is not found, the map will be retrieved
from directory services instead.
To retrieve entries from directory services,
automountd(8) daemon runs
/etc/autofs/include, which is usually a shell
script, with map name as the only command line parameter. The script should
output entries formatted according to auto_master
or
automounter map syntax to standard output. An example script to use LDAP is
included in /etc/autofs/include_ldap. It can be
symlinked to /etc/autofs/include.
auto_master
file.auto_master
configuration file functionality was
developed by Edward Tomasz Napierala
<trasz@FreeBSD.org>
under sponsorship from the FreeBSD Foundation.
The auto_master
configuration file
functionality was ported to DragonFly and
NetBSD by Tomohiro Kusumi
<kusumi.tomohiro@gmail.com>.
-media
special map is currently unsupported on
NetBSD.
November 25, 2017 | NetBSD 9.4 |