tmux cssh and ansible

tssh -e dev webservers

tssh -e prod webservers

tssh -e prod -l '.*-dc1-' webservers

#!/usr/bin/env bash

# by Divan Santana <divan@santanas.co.za>

# Starts a tmux CSSH session based on Ansible inventory.

# TODO: Add support for -e 'all' so can cssh across environments.

########
# docs #
########

# You need the following to make this work:
# - Your search domain must include .x.example.com, as we use DNS to
# resolve names.
# - ansible, tmux installed and in your $PATH
# - Clone ansible code repository[1] somewhere locally
# [1]: https://code.example.com:7990/projects/DEVOPS/repos/ansible
# - Set src_ansible to path of local git ansible repository
# Ideally symlink this script into your $PATH like so:
# ln -s ~/src/work/digital-ansible/extras/tssh ~/.local/bin/tssh
# - run it, like so:
# tssh -e int webserver_hosts
# or
# tssh -e prod -l '~.*-dc1- webserver_hosts

#############
# debugging #
#############

# export DEBUG='true'
# to enable debugging before running this.
[ "$DEBUG" == 'true' ] && set -x

##################
# config options #
##################
# Set this to where you clone the ansible site project.
src_ansible="${HOME}/src/work/digital-ansible"

##############
# help usage #
##############
usage() {
    echo "Usage: $0 [options] hostpattern" >&2
    echo "" >&2
    echo "Starts a tmux CSSH session based on Ansible inventory." >&2
    echo "" >&2
    echo "Options:" >&2
    echo "  -h                Show help" >&2
    echo "  -e <environment>  Ansible environment" >&2
    echo "  -l <limit>        Further limit selected hosts to an additional pattern" >&2
}

while [ $# -ne 0 ]; do
    case $1 in
	-e)
	    shift;
	    if [ $# -eq 0 ]; then
		usage
		exit 2
	    fi
	    env="$1"; shift
	    ;;
	-l)
	    shift;
	    if [ $# -eq 0 ]; then
		limit=""; shift
	    fi
	    limit="$1"; shift
	    ;;
	-h)
	    usage
	    exit 0
	    ;;
	-*)
	    usage
	    exit 2
	    ;;
	*)
	    gname=$1; shift
	    ;;
    esac
done

if [ -z "${gname}" ]; then
    usage
    exit 2
fi

######################
# requirements check #
######################

if ! type tmux > /dev/null 2>&1 ; then
    echo "tmux not found. Is it installed?" >&2
    exit 2
fi

if ! type ansible > /dev/null 2>&1 ; then
    echo "ansible not found. Is it installed?" >&2
    exit 2
fi

if ! [ -d "${src_ansible}" ] ; then
    echo "ansible code base '${src_ansible}' not found." >&2
    echo "Set var 'src_ansible' to location of ansible site git checkout." >&2
    exit 2
fi

cd "${src_ansible}"

if ! [ -f "inventories/manual_inventory_${env}.ini" ] ; then
    echo "File inventories/manual_inventory_${env}.ini not found." >&2
    echo "Set environment to either dev, int, pp, lt or prod. " >&2
    exit 2
fi

########
# main #
########

_tmux_session_name="tmux-${env}-${gname}"
# trim tmux session name, cut _hosts
tmux_session_name=`echo ${_tmux_session_name}|awk -F'_hosts' '{print $1}'`

_hosts=`ansible -i inventories/manual_inventory_${env}.ini --list-hosts ${gname} -l "${limit}" | sed -e '1,1d'`
# trim whitespace.
hosts="$(echo ${_hosts}|xargs)"

if [ -z "${hosts}" ]; then
    exit 1
fi

# Find a name for a new session
n=0; while tmux has-session -t "${tmux_session_name}-${n}" 2>/dev/null; do n=$(($n + 1)); done
tmux_session="${tmux_session_name}-${n}"

# Open a new session and split into new panes for each SSH session
for host in ${hosts}; do
    if ! tmux has-session -t "${tmux_session}" 2>/dev/null; then
	tmux new-session -s "${tmux_session}" -d "ssh ${ssh_options} ${host}"
    else
	tmux split-window -t "${tmux_session}" -d "ssh ${ssh_options} ${host}"
	# We have to reset the layout after each new pane otherwise the panes
	# quickly become too small to spawn any more
	tmux select-layout -t "${tmux_session}" tiled
    fi
done

# Synchronize panes by default
tmux set-window-option -t "${tmux_session}" synchronize-panes on

if [ -n "${TMUX}" ]; then
    # We are in a tmux, just switch to the new session
    tmux switch-client -t "${tmux_session}"
else
    # We are NOT in a tmux, attach to the new session
    tmux attach-session -t "${tmux_session}"
fi

exit 0