bashrc port forward helper

portforward.sh

# add these functions in ~/.bashrc
#
# Easier port forwarding - usage:
#
# $ portforward 9204 stageX localhost 9200
#
# where 'stageX' is an alias from ~/.ssh/config
# 9200 is the remote port on localhost
# 9204 is local port
#
function portforward() {
    if [[ $# -le 1 ]]
    then
        echo "Usage: portforward LOCAL_PORT HOST REMOTE_HOST REMOTE_PORT";
        return
    fi

    LOCAL_PORT=$1
    HOST=$2
    REMOTE_HOST=$3
    REMOTE_PORT=$4

    if ! [[ `lsof -i :$LOCAL_PORT | grep COMMAND` ]]
    then
        # Port is free - woop!
        echo "ssh -L $LOCAL_PORT:$REMOTE_HOST:$REMOTE_PORT $HOST -N"
        ssh -L $LOCAL_PORT:$REMOTE_HOST:$REMOTE_PORT $HOST -N 2> /dev/null
        [[ $? -ne 0 ]] && echo "Unable to connect to $HOST"
    else
        # Recursion ftw
        portforward $HOST $REMOTE_PORT
    fi
}

function _portforward() {
    # Only autocomplete on the first arg
    if [[ ${COMP_WORDS[COMP_CWORD-1]} == "portforward" ]]
    then
        # Extract host aliases from ~/.ssh/config
        HOSTS=$(grep --color=never "^Host " ~/.ssh/config | awk '{if ($2 != "*") print $2}')
        CURRENT_WORD="${COMP_WORDS[COMP_CWORD]}"
        COMPREPLY=($(compgen -W "$HOSTS" -- $CURRENT_WORD))
        return 0
    fi
}

complete -F _portforward portforward