xref: /freebsd/usr.sbin/autofs/auto_master.5 (revision 63a938566d524836885917d95bd491aa4400b181)
1.\" Copyright (c) 2014 The FreeBSD Foundation
2.\" All rights reserved.
3.\"
4.\" This software was developed by Edward Tomasz Napierala under sponsorship
5.\" from the FreeBSD Foundation.
6.\"
7.\" Redistribution and use in source and binary forms, with or without
8.\" modification, are permitted provided that the following conditions
9.\" are met:
10.\" 1. Redistributions of source code must retain the above copyright
11.\"    notice, this list of conditions and the following disclaimer.
12.\" 2. Redistributions in binary form must reproduce the above copyright
13.\"    notice, this list of conditions and the following disclaimer in the
14.\"    documentation and/or other materials provided with the distribution.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\" $FreeBSD$
29.\"
30.Dd March 13, 2015
31.Dt AUTO_MASTER 5
32.Os
33.Sh NAME
34.Nm auto_master
35.Nd auto_master and map file format
36.Sh DESCRIPTION
37The automounter configuration consists of the
38.Nm
39configuration file, which assigns filesystem paths to map names,
40and maps, which contain actual mount information.
41The
42.Nm
43configuration file is used by the
44.Xr automount 8
45command.
46Map files are read by the
47.Xr automountd 8
48daemon.
49.Sh AUTO_MASTER SYNTAX
50The
51.Nm
52file consists of lines with two or three entries separated by whitespace
53and terminated by newline character:
54.Bd -literal -offset indent
55.Pa mountpoint Pa map_name Op Ar -options
56.Ed
57.Pp
58.Pa mountpoint
59is either a fully specified path, or
60.Li /- .
61When
62.Pa mountpoint
63is a full path,
64.Pa map_name
65must reference an indirect map.
66Otherwise,
67.Pa map_name
68must reference a direct map.
69See
70.Sx "MAP SYNTAX" below.
71.Pp
72.Pa map_name
73specifies map to use.
74If
75.Pa map_name
76begins with
77.Li - ,
78it specifies a special map.
79See
80.Sx "MAP SYNTAX"
81below.
82If
83.Pa map_name
84is not a fully specified path
85.Pq it does not start with Li / ,
86.Xr automountd 8
87will search for that name in
88.Li /etc .
89Otherwise it will use the path as given.
90If the file indicated by
91.Pa map_name
92is executable,
93.Xr automountd 8
94will assume it is an executable map.
95See
96.Sx "MAP SYNTAX"
97below.
98Otherwise, the file is opened and the contents parsed.
99.Pp
100.Pa -options
101is an optional field that starts with
102.Li -
103and can contain generic filesystem mount options.
104.Pp
105The following example specifies that the /etc/auto_example indirect map
106will be mounted on /example.
107.Bd -literal -offset indent
108/example auto_example
109.Ed
110.Sh MAP SYNTAX
111Map files consist of lines with a number of entries separated by whitespace
112and terminated by newline character:
113.Bd -literal -offset indent
114.Pa key Oo Ar -options Oc Oo Ar mountpoint Oo -options Oc Oc Ar location Op ...
115.Ed
116.Pp
117In most cases, it can be simplified to:
118.Bd -literal -offset indent
119.Pa key Oo Ar -options Oc Ar location
120.Ed
121.Pp
122.Pa key
123is the path component used by
124.Xr automountd 8
125to find the right map entry to use.
126It is also used to form the final mountpoint.
127A wildcard
128.Pq Ql *
129can be used for the key.
130It matches every directory that does not match other keys.
131Those directories will not be visible to the user
132until accessed.
133.Pp
134The
135.Ar options
136field, if present, must begin with
137.Li - .
138When mounting the filesystem, options supplied to
139.Nm
140and options specified in the map entry are concatenated together.
141The special option
142.Li fstype
143is used to specify filesystem type.
144It is not passed to the mount program as an option.
145Instead, it is passed as an argument to
146.Cm "mount -t".
147The default
148.Li fstype
149is
150.Ql nfs .
151The special option
152.Li nobrowse
153is used to disable creation of top-level directories for special
154and executable maps.
155.Pp
156The optional
157.Pa mountpoint
158field is used to specify multiple mount points
159for a single key.
160.Pp
161The
162.Ar location
163field specifies the filesystem to be mounted.
164Ampersands
165.Pq Ql &
166in the
167.Ar location
168field are replaced with the value of
169.Ar key .
170This is typically used with wildcards, like:
171.Bd -literal -offset indent
172.Li *	192.168.1.1:/share/&
173.Ed
174.Pp
175The
176.Ar location
177field may contain references to variables, like:
178.Bd -literal -offset indent
179.Li sys	192.168.1.1:/sys/${OSNAME}
180.Ed
181.Pp
182Defined variables are:
183.Pp
184.Bl -tag -width "-OSNAME" -compact
185.It Li ARCH
186Expands to the output of
187.Li "uname -p" .
188.It Li CPU
189Same as ARCH.
190.It Li HOST
191Expands to the output of
192.Li "uname -n" .
193.It Li OSNAME
194Expands to the output of
195.Li "uname -s" .
196.It Li OSREL
197Expands to the output of
198.Li "uname -r" .
199.It Li OSVERS
200Expands to the output of
201.Li "uname -v" .
202.El
203.Pp
204Additional variables can be defined with the
205.Fl D
206option of
207.Xr automount 8
208and
209.Xr automountd 8 .
210.Pp
211To pass a location that begins with
212.Li / ,
213prefix it with a colon.
214For example,
215.Li :/dev/cd0 .
216.Pp
217This example, when put into
218.Pa /etc/auto_example ,
219and with
220.Nm
221referring to the map as described above, specifies that the NFS share
222.Li 192.168.1.1:/share/example/x
223will be mounted on
224.Pa /example/x/
225when any process attempts to access that mountpoint, with
226.Li intr
227and
228.Li nfsv4
229mount options, described in
230.Xr mount_nfs 8 :
231.Bd -literal -offset indent
232.Li x -intr,nfsv4 192.168.1.1:/share/example/x
233.Ed
234.Pp
235Automatically mount an SMB share on access, as a guest user,
236without prompting for a password:
237.Bd -literal -offset indent
238.Li share -fstype=smbfs,-N ://@server/share
239.Ed
240.Pp
241Automatically mount the CD drive on access:
242.Bd -literal -offset indent
243.Li cd -fstype=cd9660 :/dev/cd0
244.Ed
245.Sh SPECIAL MAPS
246Special maps have names beginning with
247.Li - .
248Supported special maps are:
249.Pp
250.Bl -tag -width "-hosts" -compact
251.It Li -hosts
252Query the remote NFS server and map exported shares.
253This map is traditionally mounted on
254.Pa /net .
255Access to files on a remote NFS server is provided through the
256.Pf /net/ Ar nfs-server-ip Ns / Ns Ar share-name Ns /
257directory without any additional configuration.
258Directories for individual NFS servers are not present until the first access,
259when they are automatically created.
260.It Li -media
261Query devices that are not yet mounted, but contain valid filesystems.
262Generally used to access files on removable media.
263.It Li -noauto
264Mount filesystems configured in
265.Xr fstab 5
266as "noauto".
267This needs to be set up as a direct map.
268.It Li -null
269Prevent
270.Xr automountd 8
271from mounting anything on the mountpoint.
272.El
273.Pp
274It is possible to add custom special maps by adding them, as executable
275maps named
276.Pa special_foo ,
277to the
278.Pa /etc/autofs/
279directory.
280.Sh EXECUTABLE MAPS
281If the map file specified in
282.Nm
283has the execute bit set,
284.Xr automountd 8
285will execute it and parse the standard output instead of parsing
286the file contents.
287When called without command line arguments, the executable is
288expected to output a list of available map keys separated by
289newline characters.
290Otherwise, the executable will be called with a key name as
291a command line argument.
292Output from the executable is expected to be the entry for that key,
293not including the key itself.
294.Sh INDIRECT VERSUS DIRECT MAPS
295Indirect maps are referred to in
296.Nm
297by entries with a fully qualified path as a mount point, and must contain only
298relative paths as keys.
299Direct maps are referred to in
300.Nm
301by entries with
302.Li /-
303as the mountpoint, and must contain only fully qualified paths as keys.
304For indirect maps, the final mount point is determined by concatenating the
305.Nm
306mountpoint with the map entry key and optional map entry mountpoint.
307For direct maps, the final mount point is determined by concatenating
308the map entry key with the optional map entry mountpoint.
309.Pp
310The example above could be rewritten using direct map, by placing this in
311.Nm :
312.Bd -literal -offset indent
313.Li /- auto_example
314.Ed
315.Pp
316and this in
317.Li /etc/auto_example
318map file:
319.Bd -literal -offset indent
320.Li /example/x -intr,nfsv4 192.168.1.1:/share/example/x
321.Li /example/share -fstype=smbfs,-N ://@server/share
322.Li /example/cd -fstype=cd9660 :/dev/cd0
323.Ed
324.Sh DIRECTORY SERVICES
325Both
326.Nm
327and maps may contain entries consisting of a plus sign and map name:
328.Bd -literal -offset indent
329.Li +auto_master
330.Ed
331.Pp
332Those entries cause
333.Xr automountd 8
334daemon to retrieve the named map from directory services (like LDAP)
335and include it where the entry was.
336.Pp
337If the file containing the map referenced in
338.Nm
339is not found, the map will be retrieved from directory services instead.
340.Pp
341To retrieve entries from directory services,
342.Xr automountd 8
343daemon runs
344.Pa /etc/autofs/include ,
345which is usually a shell script, with map name as the only command line
346parameter.
347The script should output entries formatted according to
348.Nm
349or automounter map syntax to standard output.
350An example script to use LDAP is included in
351.Pa /etc/autofs/include_ldap .
352It can be symlinked to
353.Pa /etc/autofs/include .
354.Sh FILES
355.Bl -tag -width ".Pa /etc/auto_master" -compact
356.It Pa /etc/auto_master
357The default location of the
358.Pa auto_master
359file.
360.It Pa /etc/autofs/
361Directory containing shell scripts to implement special maps and directory
362services.
363.El
364.Sh SEE ALSO
365.Xr autofs 5 ,
366.Xr automount 8 ,
367.Xr automountd 8 ,
368.Xr autounmountd 8
369.Sh AUTHORS
370The
371.Nm
372configuration file functionality was developed by
373.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org
374under sponsorship from the FreeBSD Foundation.
375