NAME¶
auto.master - Master Map for automounter
DESCRIPTION¶
The
auto.master map is consulted to set up automount managed mount points
when the
autofs(8) script is invoked or the
automount(8) 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.
The default location of the master map is
/etc/auto.master 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
MASTER_MAP_NAME
configuration variable in
/etc/default/autofs. 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.
Access to mounts in maps is governed by a key.
For direct maps the mount point is always specified as:
/-
and the key used within the direct map is the full path to the mount point.
For indirect maps access is by using the path scheme:
/
mount-point/
key
where
mount-point is one of the entries listed in the master map. The
key is a single directory component and is matched against entries in
the map given in the entry (See
autofs(5)).
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:
+ [maptype
,format
:]map
[options
] and
automount(8) will process the map according to the specification
described below for map entries.
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.
The format of a master map entry is:
- mount-point [map-type[,format]:]map [options]
- mount-point
- Base location for the autofs filesystem to be
mounted. For indirect maps this directory will be created (as with
mkdir -p) and is removed when the autofs filesystem is
umounted.
- map-type
- Type of map used for this mount point. The following are
valid map types:
- file
- The map is a regular text file.
- 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.
- yp
- The map is a NIS (YP) database.
- nisplus
- The map is a NIS+ database.
- hesiod
- The map is a hesiod database whose filsys entries
are used for maps.
- ldap or ldaps
- The map is stored in an LDAP directory. If ldaps is
used the appropriate certificate must be configured in the LDAP
client.
- multi
- This map type allows the specification of multiple maps
separated by "--". These maps are searched in order to resolve
key lookups.
- dir
- This map type can be used at + 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.
- format
- Format of the map data; currently the only formats
recognized are sun, which is a subset of the Sun automounter map
format, and hesiod, for hesiod filesys entries. If the format is
left unspecified, it defaults to sun for all map types except
hesiod.
- map
- Name of the map to use. This is an absolute UNIX pathname
for maps of types file, dir, or program, and the name
of a database in the case for maps of type yp, nisplus, or
hesiod or the dn of an LDAP entry for maps of type
ldap.
- options
- Any remaining command line arguments without leading dashes
(-) are taken as options ( -o) to mount. Arguments with
leading dashes are considered options for the maps.
The sun format supports the following options:
- -Dvariable=value
- Replace variable with value in map
substitutions.
- -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.
- 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.
Bind mounting of NFS file systems can also be prevented for specific map
entrys by adding the "port=" mount option to the entries.
- -r, --random-multimount-selection
- Enables the use of ramdom 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.
- -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.
- -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.
GENERAL SYSTEM DEFAULTS CONFIGURATION¶
The default value of several general settings may be changed in the
configuration file
/etc/default/autofs. They are:
- TIMEOUT
- sets the default mount timeout (program default 600).
- NEGATIVE_TIMEOUT
- Set the default timeout for caching failed key lookups
(program default 60). If the equivalent command line option is given it
will override this setting.
- MOUNT_WAIT
- Set the default time to wait for a response from a spawned
mount(8) before sending it a SIGTERM. Note that we still need to wait for
the RPC layer to timeout before the sub-process exits so this isn't ideal
but it is the best we can do. The default is to wait until mount(8)
returns without intervention.
- UMOUNT_WAIT
- Set the default time to wait for a response from a spawned
umount(8) before sending it a SIGTERM. Note that we still need to wait for
the RPC layer to timeout before the sub-process exits so this isn't ideal
but it is the best we can do.
- BROWSE_MODE
- Maps are browsable by default (program default
"yes").
- MOUNT_NFS_DEFAULT_PROTOCOL
- Specify the default protocol used by mount.nfs(8) (program
default 3). Since we can't identify this default automatically we need to
set it in the autofs configuration.
- APPEND_OPTIONS
- Determine whether global options, given on the command line
or per mount in the master map, are appended to map entry options or if
the map entry options replace the global options (program default
"yes", append options).
- LOGGING
- set default log level "none", "verbose"
or "debug" (program default "none").
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.
For example, with an entry in the master map of
/net -hosts accessing
/net/myserver will mount exports from myserver on directories below
/net/myserver.
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.
LDAP MAPS¶
If the map type
ldap is specified the mapname is of the form
[//servername/]dn, where the optional
servername is the name of
the LDAP server to query, and
dn is the Distinguished Name of a subtree
to search for map entries. The old style
ldap:servername:mapname 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.
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.
There are three common schemas in use:
- nisMap
- Entries in the nisMap schema are nisObject
objects in the specified subtree, where the cn attribute is the key
(the wildcard key is "/"), and the nisMapEntry attribute
contains the information used by the automounter.
- automountMap
- The automountMap schema has two variations that
differ in the attribute used for the map key. Entries in the automountMap
schema are automount objects in the specified subtree, where the
cn or automountKey attribute (depending on local usage) is
the key (the wildcard key is "/"), and the
automountInformation attribute contains the information used by the
automounter. Note that the cn attribute is case insensitive.
The object classes and attributes used for accessing automount maps in LDAP can
be changed by setting entries in the autofs configuration located in
/etc/default/autofs.
- 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.
The configuration settings available are:
- LDAP_TIMEOUT
- Set the network response timeout (default 8). Set timeout
value for the synchronous API calls. The default is the LDAP library
default of an infinite timeout.
- LDAP_NETWORK_TIMEOUT
- Set the network response timeout (default 8).
- LDAP_URI
- A space separated list of server uris of the form
<proto>://<server>[/] where <proto> can be ldap or
ldaps. The option can be given multiple times. Map entries that include a
server name override this option and it is then not used. Default is an
empty list in which case either the server given in a map entry or the
LDAP configured default is used. This uri list is read at startup and
whenever the daemon receives a HUP signal.
This configuration option can also be used to request autofs lookup SRV RRs for
a domain of the form <proto>:///[<domain dn>]. Note that a
trailing "/" is not allowed when using this form. If the domain dn
is not specified the dns domain name (if any) is used to construct the domain
dn for the SRV RR lookup. The server list returned from an SRV RR lookup is
refreshed according to the minimum ttl found in the SRV RR records or after
one hour, whichever is less.
- SEARCH_BASE
- The base dn to use when searching for amap base dn. This
entry may be given multiple times and each will be checked for a map base
dn in the order they occur in the configuration. The search base list is
read at startup and whenever the daemon recieves a HUP signal.
- MAP_OBJECT_CLASS
- The map object class. In the nisMap schema this
corresponds to the class nisMap and in the automountMap
schema it corresponds to the class automountMap.
- ENTRY_OBJECT_CLASS
- The map entry object class. In the nisMap schema
this corresponds to the class nisObject and in the
automountMap schema it corresponds to the class
automount.
- MAP_ATTRIBUTE
- The attribute used to identify the name of the map to which
this entry belongs. In the nisMap schema this corresponds to the
attribute nisMapName and in the automountMap schema it
corresponds to the attribute ou or automountMapName.
- ENTRY_ATTRIBUTE
- The attribute used to identify a map key. In the
nisMap schema this corresponds to the attribute cn and in
the automountMap schema it corresponds to the attribute
automountKey.
- VALUE_ATTRIBUTE
- The attribute used to identify the value of the map entry.
In the nisMap schema this corresponds to the attribute
nisMapEntry and in the automountMap schema it corresponds to
the attribute automountInformation.
- NOTE:
- It is essential that entries use class and attribute in a
consistent manner for correct operation of autofs. For example mixing
cn and automountKey attributes in automount schema
map entries won't work as expected.
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
/etc/autofs_ldap_auth.conf. If this file
exists it will be used to establish whether TLS or authentication should be
used.
An example of this file is:
<?xml version="1.0" ?>
<autofs_ldap_sasl_conf
usetls="yes"
tlsrequired="no"
authrequired="no"
authtype="DIGEST-MD5"
user="xyz"
secret="abc"
/>
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.
In OpenLDAP these may be configured in the
ldap.conf 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.
See
autofs_ldap_auth.conf(5) for more information.
EXAMPLE¶
/- auto.data
/home /etc/auto.home
/mnt yp:mnt.map
This will generate two mountpoints for
/home and
/mnt and install
direct mount triggers for each entry in the direct mount map
auto.data.
All accesses to
/home will lead to the consultation of the map in
/etc/auto.home and all accesses to
/mnt will consult the NIS map
mnt.map. All accesses to paths in the map
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
auto.data.
SEE ALSO¶
automount(8),
autofs(5),
autofs(8).
autofs_ldap_auth.conf(5)
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> .
