Distributed ssh client written in Perl. Standalon so doesn't depend on any libraries etc.
dssh dssh - Distributed execution of commands
VERSION
SYNOPSIS dssh [-h]
dssh [-w *host1,host2* | -W *host1,host2*] [-f *hostfile1,hostfile2*]
[-q]
dssh [-w *host1,host2* | -W *host1,host2*] [-f *hostfile1,hostfile2*]
[-c | [[-a] [-ne] [-no] [-nl] [-np] [-no]] [-g *server group*]
[-l *login name*] [-t *time out*] *command*
DESCRIPTION What is dssh dssh stands for distributed secure shell. It's derived from the dsh implementation as included by IBM in their PSSP software. The major difference is, that dssh supports executing remote commands using SSH rather than the unsecure rsh. Furthermore some dsh features are missing while other features have been added. dssh Is YABA compatible.
Command line options -h Help message
-w *host1,host2*
Specify one or multiple hosts, separated by commas, on which the
command should be executed.
-W *host1,host2*
Specify one or multiple hosts, separated by commas, on which the
command should be executed which will be added to the default list.
-f *hostfile1,hostfile2*
Specify the host file. Multiple host files should be separated by a
comma. Use absolute filenames.
-q List the hosts. This won't execute any commands.
-a Show an activity bar. Will not be shown when -np or -c is specified.
-l *login name*
Remote login name. Default is current user name.
-t *timeout*
Specify the per process time out. This defaults to 60 seconds.
-c Compress output. Emulates the behaviour of dshbak and summarizes the
output of hosts which have the same output.
-g *group1,group2*
Server group. When specified, only processes servers which belong to
this group. Multiple groups shoud be separated by a comma.
-ne Don't display standard error output from remote command. Can't be
used together with -no.
-no Don't display standard output from remote command. Can't be used
together with -ne.
-nh Don't display the hostname in front of every line.
-nl Removes empty lines from output.
-np Don't display separators.
A SHORT INTRODUCTION Before using dssh, make sure you have distributed your public keys to all the hosts you want to access. Furthermore, you need to use an unencrypted key (not recommended) or setup ssh-agent (prefered). The last option will give you the benefit of using an unencrypted key, while the private key is still encrypted.
The following command is an example of how to execute the command
"ls -l" on the host nlassv66 using dssh:
"dssh -w nlassv66 -- ls -l"
Using the -w option you can specify one or multiple hosts on which you
want to execute the command. Multiple hosts should be separated by a
comma. Everything that's typed after the -- won't be evaluated as an
argument. If you want to be sure that a command won't get evaluated by
dssh or the shell, place the command between quotes. Example:
"dssh -w nlassv66,nlassv67 "ls -l""
When you enter dssh with a command, but without any options:
"dssh "ls -l""
dssh will try to locate the default collective file, which is
"~/.sshcoll", read the hosts which are in the file and execute the
command on these hosts.
When you want to specify your own coll file, use the -f parameter:
"dssh -f /home/<user>/.sshcoll.ce "ls -l""
The -w options will override the coll file specified by -f.
You can supply multiple coll files. Seperate them by a comma:
"dssh -f /home/<user>/.sshcoll.ce,/home/<user>/.sshcoll.li "ls -l""
When you specify a coll file and you want to add hosts which are missing
from that file, use the -W options. This will add the specified hosts to
the host list:
"dssh -f /home/<user>/.sshcoll.ce -W myhost1,myhost2 "ls -l""
This will also work:
"dsh -w myhost1,myhost2 -W myhost3,myhost4 "ls -l""
If you want to see the hosts on which a command will be executed, use
the -q option.
"dssh -f /home/<user>/.sshcoll.ce -W myhost1,myhost2 -q"
When executing a command on multiple hosts, it might take long before
dssh is finished. To see if dssh is still active, use to -a option to
display an activity symbol. Whenever a command gets executed or is
finished, the symbol will change.
"dssh -a "ls -l""
The default user for dssh commands is the current user name. If you want
your commands to be executed as a different user, specify one using the
-l option:
"dssh -l <myuser> "ls -l""
When a command is executed, a maximum time for executing will be set.
When this has expired, the command will be killed. The default time is
60, which might be too short for some commands to finish. Therefore you
can specify the timout using the -t option:
"dssh -t 65 "sleep 60""
On AIX systems which have PSSP installed, there's a program called
dshbak. This program collects output from the dsh command and
'compresses' it. When the output for certain hosts is the same, that
output will only be printed once.
"dssh -c "ls /usr/bin""
If you don't want to see the standard error output from a command, use
the -ne options:
"dssh -ne "ls -l idontexist""
If you don't want to see the standard output from a command, use the -no
options:
"dssh -no "ls -l""
Empty lines can be filtered by using the -nl option:
"dssh -nl "echo '';echo hi;echo ''""
If you only need the output without the fancy separators, use the -np
option.
"dssh -np "ls -l""
To leave out the hostname, use -nh:
"dssh -nh "ls -l""
Groups When you have a coll file for a certain customer, it might also be nice if there was another way of selecting hosts within that file without specifing them on the command line. This can be done using groups. A group is an identifier in a coll file, which groups together one or more hosts. Lets say that the following output is from our coll file and contains 6 hosts.
host1
host2
host3
host4
host5
host6
Now imagine, that host1 and host2 belong to SAP instance HB1, while
host3 and host4 are CWS's. When you want to execute a command on the
CWS's you have three options. Specify the hosts on the command line
using the -w option, create a separate coll file or create groups in the
current coll file. We'll take the last option.
@CWS:host3,host4
@HB1:host1,host2
host5
host6
If you want to execute a command on all the servers in your coll file,
you can use dssh without any additional parameters:
"dssh "ls -l""
dssh will totally ignore the groups and create a list from all the hosts
in your coll file. But what if you only want to execute a command on the
CWS's (host3 and host4)? Then you should use the -g option to specify
the group:
"dssh -g CWS "ls -l""
You can also specify multiple groups. Seperate them by a comma.
"dssh -g CWS,HB1 "ls -l""
Furthermore, it's also possible for a host to belong to multiple groups.
Whenever a command gets executed and a host has multiple entries in the
coll file, dssh will remove the duplicates internally.
Another example:
@CE:host1,host2,host3,host4
@LI:host5,host6,host7,host8
@CLASS:host9,host10
@CECWS:host1,host3
@LICWS:host5,host8
@TSM:host8
@HB1:host1
@HB2:host2
User configuration A user can create its own personal configuration file in which he can set some default settings which affect the behaviour of dssh. These settings shoud be placed in /.dssh . The format of this file is:
<identifier>=<value>
Just like other configuration files, the lines can be commented out, or
a comment can be put in at the end of a line. The user can specify the
following identifiers:
Exec *[0|1]*
Don't execute commands (0)
timeout *seconds*
Per process time out in seconds
hostFile *hostfile*
Absolute path to the default collective host file
groups *group1,group2*
Default host group(s)
showErr *[0|1]*
Don't display standard error output (0)
showOut *[0|1]*
Don't display standard output (0)
showHost *[0|1]*
Don't display hostname at beginning of line (0)
pretty *[0|1]*
Don't display separators (0)
user *username*
User as which the commands will be execute on the remote hosts
maxConcurrentChilds *number*
Set the maximum number of processes that can be running at the same
time. Don't touch this setting unless you know what your doing !!!
compress *[0|1]*
Compress output (1)
Example
user=sysmgr
hostFile=/home/<user>/.sshcoll.int
compress=1
groups=CWS,DNS
When a user issues a dssh command without any additional parameters the
command will be executed as user sysmgr, on hosts in the file
/home/<user>/.sshcoll.int which belong to the groups CWS or DNS and
compressed output.
bindAddress *IP adress or hostname*
Host of which the connection will be originating. This is usefull
for hosts which have multiple network adapter.
AUTHOR alexdepalex
KNOWN BUGS yes
REPORTING BUGS Report bugs to me
COPYRIGHT yes
POD ERRORS Hey! The above document had some coding errors, which are explained below:
Around line 1660:
'=item' outside of any '=over'
Around line 1664:
You forgot a '=back' before '=head1'