| 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:
ARCHuname -p.CPUARCH.HOSTuname -n.OSNAMEuname -s.OSRELuname -r.OSVERSuname -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-nullIt 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 |