NAME¶
cssh, crsh, ctel, ccon - Cluster administration tool
SYNOPSIS¶
cssh [options] [[user@]<server>[:port]|<tag>] [...]
crsh [options] [[user@]<server>[:port]|<tag>] [...]
ctel [options] [<server>[:port]|<tag>] [...]
ccon [options] [[user@]<server>[:port]|<tag>] [...]
DESCRIPTION¶
The command opens an administration console and an xterm to all specified hosts.
Any text typed into the administration console is replicated to all windows.
All windows may also be typed into directly.
This tool is intended for (but not limited to) cluster administration where the
same configuration or commands must be run on each node within the cluster.
Performing these commands all at once via this tool ensures all nodes are kept
in sync.
Connections are opened via ssh so a correctly installed and configured ssh
installation is required. If, however, the program is called by
"crsh" then the rsh protocol is used (and the communications channel
is insecure), or by "ctel" then telnet is used, or by
"ccon" then console is used.
Extra caution should be taken when editing system files such as /etc/inet/hosts
as lines may not necessarily be in the same order. Assuming line 5 is the same
across all servers and modifying that is dangerous. Better to search for the
specific line to be changed and double-check before changes are committed.
Further Notes¶
Please also see "KNOWN BUGS".
- •
- The dotted line on any sub-menu is a tear-off, i.e. click
on it and the sub-menu is turned into its own window.
- •
- Unchecking a hostname on the Hosts sub-menu will unplug the
host from the cluster control window, so any text typed into the console
is not sent to that host. Re-selecting it will plug it back in.
- •
- If your window manager menu bars are obscured by terminal
windows see the "screen_reserve_XXXXX" options in the
.clusterssh/config file (see "FILES").
- •
- If the terminals overlap too much see the
"terminal_reserve_XXXXX" options in the
.clusterssh/config file (see "FILES").
- •
- If the code is called as crsh instead of cssh (i.e. a
symlink called crsh points to the cssh file or the file is renamed) rsh is
used as the communications protocol instead of ssh.
- •
- If the code is called as ctel instead of cssh (i.e. a
symlink called ctel points to the cssh file or the file is renamed) telnet
is used as the communications protocol instead of ssh.
- •
- If the code is called as ccon instead of cssh (i.e. a
symlink called ccon points to the cssh file or the file is renamed)
console is used as the communications protocol instead of ssh.
- •
- When using cssh on a large number of systems to connect
back to a single system (e.g. you issue a command to the cluster to scp a
file from a given location) and when these connections require
authentication (i.e. you are going to authenticate with a password), the
sshd daemon at that location may refuse connects after the number
specified by MaxStartups in sshd_config is exceeded. (If this value is not
set, it defaults to 10.) This is expected behavior; sshd uses this
mechanism to prevent DoS attacks from unauthenticated sources. Please tune
sshd_config and reload the SSH daemon, or consider using the
~/.ssh/authorized_keys mechanism for authentication if you encounter this
problem.
- •
- If client windows fail to open, try running:
"cssh -e {single host name}"
This will test the mechanisms used to open windows to hosts. This could be
due to either the "-xrm" terminal option which enables
"AllowSendEvents" (some terminal do not require this option,
other terminals have another method for enabling it - see your terminal
documention) or the "ConnectTimeout" ssh option (see the
configuration option "-o" or file .clusterssh/config
below to resolve this).
OPTIONS¶
Some of these options may also be defined within the configuration file. Default
options are shown as appropriate.
- --action,-a '<command>'
- Run the command in each session, i.e. "-a 'vi
/etc/hosts'" to drop straight into a vi session. NOTE: not all
communications methods support this (ssh and rsh should, telnet and
console will not).
- --autoclose,-A <seconds>
- Number of seconds to wait before closing finished terminal
windows.
- --autoquit,-q|--no-autoquit,-Q
- Enable|Disable automatically quiting after the last client
window has closed (overriding the config file)
- --cluster-file,-c <file>
- Use supplied file as additional cluster file (see also
"FILES")
- --config-file,-C <file>
- Use supplied file as additional configuration file (see
also "FILES")
- -d
- DEPRECATED. See '--debug'.
- -D
- DEPRECATED. See '--debug'.
- --debug [number].
- Enable debugging. Either a level can be provided or the
option can be repeated multiple times. Maximum level is 4.
- --evaluate,-e [user@]<hostname>[:port]
- Display and evaluate the terminal and connection arguments
so display any potential errors. The <hostname> is required to aid
the evaluation.
- --font,-f "5x8"
- Specify the font to use in the terminal windows. Use
standard X font notation.
- --help,-h|-?
- Show basic help text, and exit
- --list, -L
- List available cluster tags.
- --man,-H
- Show full help test (the man page), and exit
- --master,-M <master>
- The console client program polls master as the primary
server, rather than the default set at compile time (typically
``console'').
- --options,-o "-x -o ConnectTimeout=10" - for ssh
connections
- --options,-o "" - for rsh connections
- Specify arguments to be passed to ssh or rsh when making
the connection.
NOTE: any "generic" change to the method (i.e. specifying
the ssh port to use) should be done in the medium's own config file (see
"ssh_config" and $HOME/.ssh/config).
- --output-config,-u
- Output the current configuration in the same format used by
the $HOME/.clusterssh/config file.
- --port,-p <port>
- Specify an alternate port for connections.
- --show-history,-s
- IN BETA: Show history within console window. This code is
still being worked upon, but may help some users.
- --term-args,-t ""
- Specify arguments to be passed to terminals being used
- --tile,-g|--no-tile,-G
- Enable|Disable window tiling (overriding the config
file)
- --title,-T "CSSH"
- Specify the initial part of the title used in the console
and client windows
- --use_all_a_records,-A
- If a hostname resolves to multiple IP addresses, toggle
whether or not to connect to all of them, or just the first one (see also
config file entry)
- --username,-l $LOGNAME
- Specify the default username to use for connections (if
different from the currently logged in user). NOTE: will be
overridden by <user>@<host>
- --version,-v
- Show version information and exit
ARGUMENTS¶
The following arguments are support:
- [user@]<hostname>[:port] ...
- Open an xterm to the given hostname and connect to the
administration console. An optional port number can be used if sshd is not
listening on standard port (e.g not listening on port 22) and ssh_config
cannot be used.
- <tag> ...
- Open a series of xterms defined by <tag> within
either /etc/clusters or $HOME/.clusterssh/clusters
(see "FILES").
Note: specifying a username on a cluster tag will override any usernames
defined in the cluster
KEY SHORTCUTS¶
The following key shortcuts are available within the console window, and all of
them may be changed via the configuration files.
- Control-q
- Quit the program and close all connections and windows
- Control-+
- Open the 'Add Host(s) or Cluster(s)' dialogue box. Mutiple
host or cluster names can be entered, separated by spaces.
- Alt-n
- Paste in the hostname part of the specific connection
string to each client, minus any username or port, i.e.
"scp /etc/hosts server:files/<Alt-n>.hosts"
would replace the <Alt-n> with the client's name in each window
- Alt-r
- Retile all the client windows
EXAMPLES¶
- Open up a session to 3 servers
- $ cssh server1 server2 server3
- Open up a session to a cluster of servers identified by the
tag 'farm1' and give the controlling window a specific title, where the
cluster is defined in one of the default configuration files
- $ cssh -T 'Web Farm Cluster 1' farm1
- Connect to different servers using different login names.
NOTE: this can also be achieved by setting up appropriate options in the
.ssh/config file. Do not close cssh when last terminal exits.
- $ cssh -Q user1@server1 admin@server2
- Open up a cluster defined in a non-default configuration
file
- $ cssh -c $HOME/cssh.config db_cluster
- Use telnet on port 2022 instead of ssh
- $ ctel -p 2022 server1 server2
- Use rsh instead of ssh
- $ crsh server1 server2
- Use console with master as the primary server instead of
ssh
- $ ccon -M master server1 server2
FILES¶
- /etc/clusters
- This file contains a list of tags to server names mappings.
When any name is used on the command line it is checked to see if it is a
tag. If it is a tag, then the tag is replaced with the list of servers.
The formated is as follows:
<tag> [user@]<server> [user@]<server> [...]
i.e.
# List of servers in live
live admin1@server1 admin2@server2 server3 server4
All comments (marked by a #) and blank lines are ignored. Tags may be
nested, but be aware of recursive tags which are not checked for.
Clusters may also be specified either directly (see "clusters"
configuration options) or indirectly (see "extra_cluster_file"
configuration option) in the users
$HOME/.clusterssh/clusters file.
NOTE: there is a special cluster tag called "default" - any tags
or hosts included within this tag will be automatically opened if no other
tags are specified on the command line.
- /etc/csshrc &
$HOME/.clusterssh/config
- This file contains configuration overrides - the defaults
are as marked. Default options are overwritten first by the global file,
and then by the user file.
NOTE: values for entries do not need to be quoted unless it is
required for passing arguments, i.e.
terminal_allow_send_events="-xrm '*.VT100.allowSendEvents:true'"
should be written as
terminal_allow_send_events=-xrm '*.VT100.allowSendEvents:true'
- always_tile = yes
- Setting to anything other than "yes" does not
perform window tiling (see also -G).
- auto_close = 5
- Close terminal window after this many seconds. If set to 0
will instead wait on input from the user in each window before closing.
Can be overridden by "-K" on the command line
- auto_quit = yes
- Automatically quit after the last client window closes. Set
to anything other than "yes" to disable. Can be overridden by
"-Q" on the command line.
- clusters = <blank>
- Define a number of cluster tags in addition to (or to
replace) tags defined in the /etc/clusters file. The format is:
clusters = <tag1> <tag2> <tag3>
<tag1> = host1 host2 host3
<tag2> = user@host4 user@host5 host6
<tag3> = <tag1> <tag2>
As with the /etc/clusters file, be sure not to create recursivly
nested tags.
- comms = ssh
- Sets the default communication method (initially taken from
the name of program, but can be overridden here).
- console_position = <null>
- Set the initial position of the console - if empty then let
the window manager decide. Format is '+<x>+<y>', i.e. '+0+0'
is top left hand corner of the screen, '+0-70' is bottom left hand side of
screen (more or less).
- extra_cluster_file = <null>
- Define an extra cluster file in the format of
/etc/clusters. Multiple files can be specified, seperated by
commas. Both ~ and $HOME are acceptable as a to reference the users home
directory, i.e.
extra_cluster_file = ~/clusters, $HOME/clus
- ignore_host_errors
- THIS OPTION IS DEPRECATED. It has been left in so current
systems continue to function as expected.
- key_addhost = Control-Shift-plus
- Default key sequence to open AddHost menu. See below notes
on shortcuts.
- key_clientname = Alt-n
- Default key sequence to send cssh client names to client.
See below notes on shortcuts.
- key_paste = Control-v
- Default key sequence to paste text into the console window.
See below notes on shortcuts.
- key_quit = Control-q
- Default key sequence to quit the program (will terminate
all open windows). See below notes on shortcuts.
- key_retilehosts = Alt-r
- Default key sequence to retile host windows. See below
notes on shortcuts.
- max_addhost_menu_cluster_items = 6
- Maximum number of entries in the 'Add Host' menu cluster
list before scrollbars are used
- max_host_menu_items = 30
- Maximum number of hosts to put into the host menu before
starting a new column
- menu_host_autotearoff = 0
- menu_send_autotearoff = 0
- When set to non-0 will automatically tear-off the host or
send menu at program start
- mouse_paste = Button-2 (middle mouse button)
- Default key sequence to paste text into the console window
using the mouse. See below notes on shortcuts.
- rsh_args = <blank>
- ssh_args = "-x -o ConnectTimeout=10"
- Sets any arguments to be used with the communication method
(defaults to ssh arguments).
NOTE: The given defaults are based on OpenSSH, not commercial ssh
software.
NOTE: Any "generic" change to the method (i.e. specifying
the ssh port to use) should be done in the medium's own config file (see
"ssh_config" and $HOME/.ssh/config).
- screen_reserve_top = 0
- screen_reserve_bottom = 60
- screen_reserve_left = 0
- screen_reserve_right = 0
- Number of pixels from the screen side to reserve when
calculating screen geometry for tiling. Setting this to something like 50
will help keep cssh from positioning windows over your window manager's
menu bar if it draws one at that side of the screen.
- rsh = /path/to/rsh
- ssh = /path/to/ssh
- Depending on the value of comms, set the path of the
communication binary.
- terminal = /path/to/terminal
- Path to the x-windows terminal used for the client.
- terminal_args = <blank>
- Arguments to use when opening terminal windows. Otherwise
takes defaults from $HOME/.Xdefaults or
$<$HOME/.Xresources> file.
- terminal_font = 6x13
- Font to use in the terminal windows. Use standard X font
notation.
- terminal_reserve_top = 5
- terminal_reserve_bottom = 0
- terminal_reserve_left = 5
- terminal_reserve_right = 0
- Number of pixels from the terminal side to reserve when
calculating screen geometry for tiling. Setting these will help keep cssh
from positioning windows over your scroll and title bars or otherwise
overlapping the windows too much.
- terminal_colorize = 1
- If set to 1 (the default), then "-bg" and
"-fg" arguments will be added to the terminal invocation
command-line. The terminal will be colored in a pseudo-random way based on
the host name; while the color of a terminal is not easily predicted, it
will always be the same color for a given host name. After a while, you
will recognize hosts by their characteristic terminal color.
- terminal_bg_style = dark
- If set to dark, the the terminal background will be set to
black and the foreground to the pseudo-random color. If set to light, then
the foreground will be black and the background the pseudo-random color.
If terminal_colorize is zero, then this option has no effect.
- terminal_size = 80x24
- Initial size of terminals to use (note: the number of lines
(24) will be decreased when resizing terminals for tiling, not the number
of characters (80))
- terminal_title_opt = -T
- Option used with "terminal" to set the title of
the window
- terminal_allow_send_events = -xrm
'*.VT100.allowSendEvents:true'
- Option required by the terminal to allow XSendEvents to be
received
- title = cssh
- Title of windows to use for both the console and
terminals.
- unmap_on_redraw = no
- Tell Tk to use the UnmapWindow request before redrawing
terminal windows. This defaults to "no" as it causes some
problems with the FVWM window manager. If you are experiencing problems
with redraws, you can set it to "yes" to allow the window to be
unmapped before it is repositioned.
- use_all_a_records = no
- If a hostname resolves to multiple IP addresses, set to
"yes" to connect to all of them, not just the first one
found.
- use_hotkeys = yes
- Setting to anything other than "yes" will disable
all hotkeys.
- user = $LOGNAME
- Sets the default user for running commands on clients.
- window_tiling = yes
- Perform window tiling (set to "no" to
disable)
- window_tiling_direction = right
- Direction to tile windows, where "right" means
starting top left and moving right and then down, and anything else means
starting bottom right and moving left and then up
NOTE: The key shortcut modifiers must be in the form "Control",
"Alt", or "Shift", i.e. with the first letter capitalised
and the rest lower case. Keys may also be disabled individually by setting to
the word "null".
- $HOME/.csshrc_send_menu
- This (optional) file contains items to populate the send
menu. The default entry could be written as:
<send_menu>
<menu title="Hostname">
<command>%s</command>
<accelerator>ALT-n</accelerator>
</menu>
</send_menu>
Submenus can also be specified as follows:
<send_menu>
<menu title="Default Entries">
<detach>yes</detach>
<menu title="Hostname">
<command>%s</command>
<accelerator>ALT-n</accelerator>
</menu>
</menu>
</send_menu>
Caveats:
- There is currently no strict format checking of this
file.
- The format of the file may change in the future
- If the file exists the default entry (Hostname) is not
added
The following replacement macros are available:
- %s
- Hostname part of the specific connection string to each
client, minus any username or port
- %u
- Username part of the connection string to each client
- %h
- Hostname of server where cssh is being run from
- %n
- <RETURN> code
NOTE: requires XML::Simple to be installed
KNOWN BUGS¶
- 1.
- Catering for IPv6 addresses is minimal. This is due to a
conflict between IPv6 addresses and port numbers within the same server
definition since they both use the same seperator, i.e. is the following
just an IPv6 address, or an address + port number of 2323?
2001:db8::1428:2323
Exactly - I cannot tell either. the IPv6 address without a port is assumed
in those cases where it cannot be determined and a warning is issued.
Possible work arounds include:
- a.
- Use square brackets around the IPv6 address, i.e.
[2001:db8::1428]:2323 or
[2001:db8::1428:2323] as appropriate so there is no ambiguity
- b.
- Use the full IPv6 address if also using a port number - the
8th colon is assumed to be the port seperator.
- c.
- Define the IPv6 address in your /etc/hosts file, DNS or
other name service lookup mechanism and use the hostname instead of the
address.
- 2.
- Swapping virtual desktops can a redraw of all the terminal
windows. This is due to a lack of distinction within Tk between switching
desktops and minimising/maximising windows. Until Tk can tell the
difference between the two events, there is no fix (apart from rewriting
everything directly in X)
Anyone with any good ideas to fix the above bugs is more than welcome to get in
touch and/or provide a patch.
REPORTING BUGS¶
- •
- If you have issues running cssh, first try:
"cssh -e [user@]<hostname>[:port]"
This performs two tests to confirm cssh is able to work properly with the
settings provided within the .clusterssh/config file (or internal
defaults).
1. test the terminal window works with the options provided
2. test ssh works to a host with the configured arguments
Configuration options to watch for in ssh are
- Doesn't understand "-o ConnectTimeout=10" - remove the option
in the F<.clusterssh/config> file
- OpenSSH-3.8 using untrusted ssh tunnels - use "-Y" instead of "-X"
or use "ForwardX11Trusted yes' in ssh_config (if you change the
default ssh options from -x to -X)
- •
- If you require support, please run the following commands
and post it on the web site in the support/problems forum:
"perl -V"
"perl -MTk -e 'print $Tk::VERSION,$/'"
"perl -MX11::Protocol -e 'print $X11::Protocol::VERSION,$/'"
"cat /etc/csshrc $HOME/.clusterssh/config"
- •
- Use the debug switches (-d, -D, or -dD) will turn on
debugging output. However, please only use this option with one host at a
time, i.e. "cssh -d <host>" due to the amount of output
produced (in both main and child windows).
SEE ALSO¶
<
http://clusterssh.sourceforge.net/>, "ssh", Tk::overview,
X11::Protocol, "perl"
CREDITS¶
A web site for comments, requests, bug reports and bug fixes/patches is
available at <
http://clusterssh.sourceforge.net/>
AUTHOR¶
Duncan Ferguson, "<duncan_j_ferguson at yahoo.co.uk>"
LICENSE AND COPYRIGHT¶
Copyright 1999-2010 Duncan Ferguson.
This program is free software; you can redistribute it and/or modify it under
the terms of either: the GNU General Public License as published by the Free
Software Foundation; or the Artistic License.
See
http://dev.perl.org/licenses/ for more information.