xref: /freebsd/usr.sbin/autofs/auto_master.5 (revision dcf58f92e2c19a32fc171f763698e711c719badc)
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4.\" This software was developed by Edward Tomasz Napierala under sponsorship
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28.\" $FreeBSD$
29.\"
30.Dd November 21, 2014
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
175To pass a location that begins with
176.Li / ,
177prefix it with a colon.
178For example,
179.Li :/dev/cd0 .
180.Pp
181This example, when put into
182.Pa /etc/auto_example ,
183and with
184.Nm
185referring to the map as described above, specifies that the NFS share
186.Li 192.168.1.1:/share/example/x
187will be mounted on
188.Pa /example/x/
189when any process attempts to access that mountpoint, with
190.Li intr
191and
192.Li nfsv4
193mount options, described in
194.Xr mount_nfs 8 :
195.Bd -literal -offset indent
196.Li x -intr,nfsv4 192.168.1.1:/share/example/x
197.Ed
198.Pp
199Automatically mount an SMB share on access, as a guest user,
200without prompting for a password:
201.Bd -literal -offset indent
202.Li share -fstype=smbfs,-N ://@server/share
203.Ed
204.Pp
205Automatically mount the CD drive on access:
206.Bd -literal -offset indent
207.Li cd -fstype=cd9660 :/dev/cd0
208.Ed
209.Sh SPECIAL MAPS
210Special maps have names beginning with
211.Li - .
212Supported special maps are:
213.Pp
214.Bl -tag -width "-hosts" -compact
215.It Li -hosts
216This map queries the remote NFS server and maps exported volumes.
217It is traditionally mounted on
218.Pa /net .
219It enables access to files on a remote NFS server by accessing
220.Pa /net/nfs-server-ip/share-name/
221directory, without the need for any further configuration.
222.It Li -null
223This map prevents the
224.Xr automountd 8
225from mounting anything on the mountpoint.
226.El
227.Sh EXECUTABLE MAPS
228If the map file specified in
229.Nm
230has execute bit set, the
231.Xr automountd 8
232will execute it and parse the standard output instead of parsing
233the file contents.
234.Sh INDIRECT VERSUS DIRECT MAPS
235Indirect maps are referred to in
236.Nm
237by entries with a fully qualified path as a mount point, and must contain only
238relative paths as keys.
239Direct maps are referred to in
240.Nm
241by entries with
242.Li /-
243as the mountpoint, and must contain only fully qualified paths as keys.
244For indirect maps, the final mount point is determined by concatenating the
245.Nm
246mountpoint with the map entry key and optional map entry mountpoint.
247For direct maps, the final mount point is determined by concatenating
248the map entry key with the optional map entry mountpoint.
249.Pp
250The example above could be rewritten using direct map, by placing this in
251.Nm :
252.Bd -literal -offset indent
253.Li /- auto_example
254.Ed
255.Pp
256and this in
257.Li /etc/auto_example
258map file:
259.Bd -literal -offset indent
260.Li /example/x -intr,nfsv4 192.168.1.1:/share/example/x
261.Li /example/share -fstype=smbfs,-N ://@server/share
262.Li /example/cd -fstype=cd9660 :/dev/cd0
263.Ed
264.Sh DIRECTORY SERVICES
265Both
266.Nm
267and maps may contain entries consisting of a plus sign and map name:
268.Bd -literal -offset indent
269.Li +auto_master
270.Ed
271.Pp
272Those entries cause
273.Xr automountd 8
274daemon to retrieve the named map from directory services (like LDAP)
275and include it where the entry was.
276.Pp
277If the file containing the map referenced in
278.Nm
279is not found, the map will be retrieved from directory services instead.
280.Pp
281To retrieve entries from directory services,
282.Xr automountd 8
283daemon runs
284.Pa /etc/autofs/include ,
285which is usually a shell script, with map name as the only command line
286parameter.
287The script should output entries formatted according to
288.Nm
289or automounter map syntax to standard output.
290An example script to use LDAP is included in
291.Pa /etc/autofs/include_ldap .
292It can be symlinked to
293.Pa /etc/autofs/include .
294.Sh FILES
295.Bl -tag -width ".Pa /etc/auto_master" -compact
296.It Pa /etc/auto_master
297The default location of the
298.Pa auto_master
299file.
300.El
301.Sh SEE ALSO
302.Xr autofs 5 ,
303.Xr automount 8 ,
304.Xr automountd 8 ,
305.Xr autounmountd 8
306.Sh AUTHORS
307The
308.Nm
309configuration file functionality was developed by
310.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org
311under sponsorship from the FreeBSD Foundation.
312