Ubuntu Manpage: groups.conf - Configuration file for ClusterShell node groups

NAME

       groups.conf - Configuration file for ClusterShell node groups

DESCRIPTION

The ClusterShell library obtains its node groups configuration from the following sources in the
following order:

1. user configuration file ($XDG_CONFIG_HOME/clustershell/groups.conf)

2. local pip user installation ($HOME/.local/etc/clustershell/groups.conf)

3. system-wide configuration file (/etc/clustershell/groups.conf)

If no groups.conf is found, group support will be disabled.

Additional configuration files are also read from the directories set by the confdir option, if present.
See the confdir option below for further details.

Configuration files have a format in the style of RFC 822 potentially composed of several sections which
may be present in any order. There are two types of sections: Main and Group_source:

Main Global configuration options. There should be only one Main section.

Group_source
The Group_source section(s) define the configuration for each node group source (or namespace).
This configuration consists in external commands definition (map, all, list and reverse).

Only Group_source section(s) are allowed in additional configuration files.

[Main] OPTIONS
Configuration parameters of the Main section are described below.

default
Specify the default group source (group namespace) used by the NodeSet parser when the user does
not explicitly specify the group source (eg. "@io").

confdir
Optional list of directories where the ClusterShell library should look for .conf files which
define group sources to use. Each file in these directories with the .conf suffix should contain
one or more Group_source sections as documented in [Group_source] options below. These will be
merged with the group sources defined in /etc/clustershell/groups.conf to form the complete set of
group sources that ClusterShell will use. Duplicate Group_source sections are not allowed. Note:
.conf files that are not readable by the current user are ignored (except the one that defines the
default group source). The variable $CFGDIR is replaced by the path of the highest priority
configuration directory found (where groups.conf resides). The default confdir value enables both
system-wide and any installed user configuration (thanks to $CFGDIR). Duplicate directory paths
are ignored.

autodir
Optional list of directories where the ClusterShell library should look for .yaml files that
define in-file group dictionaries. No need to call external commands for these files, they are
parsed by the ClusterShell library itself. Multiple group source definitions in the same file is
supported. The variable $CFGDIR is replaced by the path of the highest priority configuration
directory found (where groups.conf resides). The default confdir value enables both system-wide
and any installed user configuration (thanks to $CFGDIR). Duplicate directory paths are ignored.

[Group_source] OPTIONS
Configuration parameters of each group source section are described below.

map Specify the external shell command used to resolve a group name into a nodeset, list of nodes or
list of nodeset (separated by space characters or by carriage returns). The variable $GROUP is
replaced before executing the command.

all Optional external shell command that should return a nodeset, list of nodes or list of nodeset of
all nodes for this group source. If not specified, the library will try to resolve all nodes by
using the list external command in the same group source followed by map for each group.

list Optional external shell command that should return the list of all groups for this group source
(separated by space characters or by carriage returns).

reverse
Optional external shell command used to find the group(s) of a single node. The variable $NODE is
previously replaced. If this upcall is not specified, the reverse operation is computed in memory
by the library from the list and map external calls. Also, if the number of nodes to reverse is
greater than the number of available groups, the reverse external command is avoided
automatically.

cache_time
Number of seconds each upcall result is kept in cache, in memory only. Default is 3600 seconds.
This is useful only for daemons using nodegroups.

When the library executes a group source external shell command, the current working directory is
previously set to the corresponding confdir. This allows the use of relative paths for third party files
in the command.

In addition to context-dependent $GROUP and $NODE variables described above, the two following variables
are always available and also replaced before executing shell commands:

• $CFGDIR is replaced by groups.conf highest priority base directory path

• $SOURCE is replaced by current source name

Each external command might return a non-zero return code when the operation is not doable. But if the
call return zero, for instance, for a non-existing group, the user will not receive any error when trying
to resolve such unknown group. The desired behaviour is up to the system administrator.

RESOURCE USAGE

       All  external  command  results  are  cached in memory to avoid multiple calls. Each result is kept for a
       limited amount of time. See cache_time option to tune this behaviour.

EXAMPLES

       Simple configuration file for local groups and slurm partitions binding.

   groups.conf
       [Main]
       default: local
       confdir: /etc/clustershell/groups.conf.d $CFGDIR/groups.conf.d
       autodir: /etc/clustershell/groups.d $CFGDIR/groups.d

       [local]
       map: sed -n 's/^$GROUP:(.*)/1/p' /etc/clustershell/groups
       list: sed -n 's/^\([0-9A-Za-z_-]*\):.*/\1/p' /etc/clustershell/groups

       [slurm]
       map: sinfo -h -o "%N" -p $GROUP
       all: sinfo -h -o "%N"
       list: sinfo -h -o "%P"
       reverse: sinfo -h -N -o "%P" -n $NODE

FILES

       /etc/clustershell/groups.conf
              System-wide node groups configuration file.

       /etc/clustershell/groups.conf.d/
              Recommended directory for additional configuration files.

       /etc/clustershell/groups.d/
              Recommended directory for autodir, where native group definition files (.yaml files) are found.

       $XDG_CONFIG_HOME/clustershell/groups.conf
              Main   user   groups.conf   configuration   file.   If   $XDG_CONFIG_HOME    is    not    defined,
              $HOME/.config/clustershell/groups.conf is used instead.

       $HOME/.local/etc/clustershell/groups.conf
              Local groups.conf user configuration file (default installation for pip --user)

AUTHOR

       Stephane Thiell, <sthiell@stanford.edu>

COPYRIGHT

       GNU Lesser General Public License version 2.1 or later (LGPLv2.1+)

1.8.4                                              2021-11-03                                     GROUPS.CONF(5)