pair-ssh-instance

#!/bin/bash

DEBUG="${DEBUG:-false}"

if [ ! "$DEBUG" = "false" ]; then
    set -x
fi

POSITIONAL=()
while [[ $# -gt 0 ]]; do
    key="$1"

    case $key in
        -s|--ssh-opts)
            SSH_OPTS="$2"
            shift # past argument
            shift # past value
            ;;
        -n|--no-keys)
            SSH_OPTS="-t -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
            shift
            ;;
        -c|--command)
            COMMAND="$2"
            shift
            shift
            ;;
        *)    # unknown option
            POSITIONAL+=("$1") # save it in an array for later
            shift # past argument
            ;;
  esac
done

set -- "${POSITIONAL[@]}" # restore positional parameters

PROG_NAME="$(basename $0)"
PAIR_ADDR="${1:-$PAIR_ADDR}"
PAIR_BASE_ADDR="${PAIR_BASE_ADDR:-pair.sharing.io}"
SSH_OPTS="${SSH_OPTS:--tA -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null}"

if [ $# -eq 0 ]; then
cat << EOF
Usage: ${PROG_NAME} [OPTS...] INSTANCE

-s|--ssh-opts specify SSH parameters
-n|--no-keys  don't forward SSH keys
-c|--command  change the command on connection

Examples:
- ${PROG_NAME} coolbox
- ${PROG_NAME} bobymcbobs
- ${PROG_NAME} 133.7.0.0
- ${PROG_NAME} -c bash heyste.pair.sharing.io
- ${PROG_NAME} -n bernokl

Notes:
- to not forward SSH keys set the 'SSH_OPTS' var to something like '-t'.
  example: SSH_OPTS=-t ${PROG_NAME} heyste
- default SSH_OPTS are '${SSH_OPTS}'
- default Pair domain is '${PAIR_BASE_ADDR}'
EOF
    exit 0
fi

function errorMsg {
        echo "error: $*" > /dev/stderr
        exit 1
}

function envEmpty {
    if [ -z "$2" ]; then
        errorMsg "'$1' is empty and is required"
    fi
}

envEmpty PAIR_ADDR "${PAIR_ADDR}"

echo "${PAIR_ADDR}" | grep -q '\.'
PAIR_ADDR_IS_FQDN_OR_IPADDR=$?
if [ "${PAIR_ADDR_IS_FQDN_OR_IPADDR}" -eq 1 ]; then
    PAIR_ADDR="${PAIR_ADDR}.${PAIR_BASE_ADDR}"
fi

COMMAND="${COMMAND:-attach}"
ssh ${SSH_OPTS} ii@${PAIR_ADDR} -- $COMMAND