focal (5) auto.master.5.gz

Provided by: autofs_5.1.6-2ubuntu0.1_amd64 bug

NAME

       auto.master - Master Map for automounter consulted by autofs

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. The direct map may have
       multiple entries in the master map.

       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.
       Plus  map  inclusion  is  only permitted in file map sources.  Indirect map entries must be unique in the
       master map so second and subsequent entries for an indirect mount point are ignored by automount(8).

       NOTE:  autofs currently does not collapse multiple slashes in paths, so it is important to  ensure  paths
              used  in  maps  are  correct. If unnecessary multiple slashes are present in a path it can lead to
              unexpected failures such as an inability to expire automounts. An exception to this is a  trailing
              slash at the end of the automount point path in the master map which will be removed if present.

FORMAT

       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.  Optionally, the  keyword  exec
                     may  be used as a synonym for program to avoid confusion with amd formatted maps mount type
                     program.

              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 formats recognized are sun, which is a subset of the Sun
              automounter map format, hesiod, for hesiod filesys entries and amd for amd formatted map  entries.
              If the format is left unspecified, it defaults to sun for all map types except hesiod unless it is
              a top level amd mount that has a configuration entry for the mount point path, in which  case  the
              format used is amd.

       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  and  are  passed  to
              automount (8).

              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.

              [no]browse
                     This  is  an autofs specific option that is a pseudo mount option and so is given without a
                     leading dash. Use of the browse option pre-creates mount  point  directories  for  indirect
                     mount maps so the map keys can be seen in a directory listing without being mounted. Use of
                     this option can cause performance problem if the indirect map is large so it should be used
                     with caution. The internal program default is to enable browse mode for indirect mounts but
                     the default installed configuration overrides this by setting BROWSE_MODE to  "no"  because
                     of  the  potential performance problem. This option does the same as the deprecated --ghost
                     option, the browse option is preferred because it is used by other autofs implementations.

              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.
                     For  direct  mount  maps  the option is only effective if specified on the first direct map
                     entry and is applied to all direct mount maps in the master map. It is ignored if given  on
                     subsequent  direct  map  entries.  It  may be used on individual map entries of both types.
                     Preventing bind mounts of NFS file systems can no longer  be  done  by  using  the  "port="
                     option, the nobind option must be used instead.

              symlink
                     This  option  makes  bind  mounting use a symlink instead of an actual bind mount. It is an
                     autofs specific option that is a pseudo mount option and so  is  given  without  a  leading
                     dash.  It  may  be  used  with  indirect  map entries only, either in the master map (so it
                     effects all map entries) or with individual map entries. The option is ignored  for  direct
                     mounts and non-root offest mount entries.

              strictexpire
                     Use  a  strict  expire  policy for this automount. Using this option means that last use of
                     autofs directory entries will not be updated  during  path  walks  so  that  mounts  in  an
                     automount  won't  be  kept  mounted by applications scanning the mount tree. Note that this
                     doesn't completely resolve the problem of expired automounts being  immediately  re-mounted
                     due to application accesses triggered by the expire itself.

              slave or private
                     This  option  allows mount propagation of bind mounts to be set to either slave or private.
                     This option may be needed when using multi-mounts that have bind mounts that bind to a file
                     system  that  is  propagation  shared.  This  is  because the bind mount will have the same
                     properties as its target which causes problems for offset  mounts.  When  this  happens  an
                     unwanted  offset mount is propagated back to the target file system resulting in a deadlock
                     when attempting to access the offset.  This option is an autofs pseudo  mount  option  that
                     can  be  used  in  the  master  map  only.  By  default, bind mounts will inherit the mount
                     propagation of the target file system.

              -r, --random-multimount-selection
                     Enables the use of random 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.

              -t, --timeout <seconds>
                     Set the expire timeout for map entries. This option can be  used  to  override  the  global
                     default given either on the command line or in the configuration.

              -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.

              --mode <octal_mode>
                     Set the directory mode for the base location of the autofs mount point.  If this option  is
                     given, autofs will chmod that directory with this mode.

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 explicitly 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 be 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.conf.

       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.

       For amd format maps a different schema is used:

       amdMap
              The amdmap schema contains attributes  amdmapName,  amdmapKey  and  amdmapValue  where  amdmapName
              contains  the  name of the containing map, amdmapKey contains the map key and amdmapValue contains
              the map entry.

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.

       To  avoid making edits to /etc/auto.master, /etc/auto.master.d may be used.  Files in that directory must
       have a ".autofs" suffix, e.g.  /etc/auto.master.d/extra.autofs.  Such files contain  lines  of  the  same
       format as the auto.master file, e.g.

         /foo    /etc/auto.foo
         /baz    yp:baz.map

SEE ALSO

       automount(8), autofs(5), autofs(8), autofs.conf(5), 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> .

                                                   11 Apr 2006                                    AUTO.MASTER(5)