csshi

A ClusterSSH utility (like cssh) for iTerm2.

The command opens an iTerm2 Window and connects over ssh to each specified host in a split pane session, with any text typed or pasted replicated to all panes through iTerm2's 'broadcast' feature by default. iTerm2's split pane controls are available as normal, so broadcast input can be toggled per-pane, sessions can be restarted, etc.

Install

Installing first time round will take a while - pyobjc is a required package and it compiles a lot of stuff as it installs. Later installs and upgrades will be much faster as the packages will be cached.

Homebrew

• Install iTerm2 however you like.
• Install csshi:
  $ brew install ilikejam/csshi/csshi
• Enable the iTerm2 Python API at:
  iTerm2 -> Settings... -> General -> Magic
  The 'Require "Automation" permission' option is OK.

Manual

• Install iTerm2 however you like.
• Install python3 e.g. with homebrew:
  $ brew install python3
• Clone this repo (or just download the 'csshi' file), make the csshi file executable, and maybe copy or link it to somewhere in your $PATH.
• Install the python iterm2 and pyobjc libs through pip:
  $ pip3 install -r requirements.txt
• Enable the iTerm2 Python API at:
  iTerm2 -> Settings... -> General -> Magic
  The 'Require "Automation" permission' option is OK.

Usage

usage: csshi [-h] [-d] [-k] [-c] [-n] [-l USERNAME] [-p PORT] [-J JUMPHOST]
             [-s SLEEP] [-o OPTIONS] [-b BINARY] [-P PROFILE] [-C COLUMNS |
             -R ROWS]
             (-L | destination ...)

Run multiple ssh connections concurrently in an iTerm2 terminal.

positional arguments:
  destination           [user@]host[:port] ssh connection specification. NB:
                        Square brackets MUST be used around IPv6 IP adresses

options:
  -h, --help            show this help message and exit
  -d, --debug           Turn on debugging
  -k, --kill-inactive   Don't create spacer panes and kill inactive panes
  -c, --caffeinate      Try to keep the Mac awake
  -n, --no-broadcast    Don't enable input broadcast
  -l, --username USERNAME
                        Login username, overridden per-host by specifying
                        'user@host'
  -p, --port PORT       ssh server port, overridden per-host by specifying
                        'host:port'
  -J, --jump JUMPHOST   ProxyJump host specification, like
                        [user@]jumphost[:port]
  -s, --sleep SLEEP     Sleep time in seconds between hosts. Defaults to 0
  -o, --options OPTIONS
                        Raw ssh options string, e.g. '-i ~/.ssh/id_ansible'.
                        Can be specified multiple times.
  -b, --binary BINARY   SSH binary to use. Defaults to 'ssh'
  -P, --profile PROFILE
                        iTerm2 settings Profile to use for csshi window.
                        Defaults to your default Profile.
  -C, --columns COLUMNS
                        Maximum number of columns to use.
  -R, --rows ROWS       Maximum number of rows to use.
  -L, --list-sessions   Print space-separated list of csshi sessions, one line
                        per window

Bugs

• If running csshi from a different terminal emulator (e.g. Terminal) and -k or -d have been supplied; csshi will dump a stack trace if iTerm2 quits from under us. We still terminate normally, so only a cosmetic issue.
• When running with -k, sessions which exit (e.g. if the hostname is not found) before all of the sessions open may not be closed automatically.

Tips

If you have a file listing hostnames to connect to, use xargs:
$ cat file_of_hosts | xargs csshi

Some preferences to optimise for shell density if you find yourself opening a lot of terminals in one csshi session:

• Disable pane menubars:
  iTerm2 -> Settings... -> Appearance -> Panes -> Show per-pane title bar with split panes
  You can still access the menu for each pane with Ctrl-click instead of the menubar burger icon
• Decrease the 'Side' and 'Top & bottom' margins:
  iTerm2 -> Settings... -> Appearance -> Panes
• Add an iTerm2 Profile (iTerm2 -> Settings... -> Profiles) with optimised font size etc, and run csshi with -P <profile name> to use it.

If you are connecting to large numbers of hosts via a single Jumphost, it's advisable to set up multiplexing for the Jumphost:
https://en.wikibooks.org/wiki/OpenSSH/Cookbook/Multiplexing
Also consider raising MaxConnections on that host - the default on OpenSSH is 10.

Contribute

Throw a PR over, raise an issue, send me an email.