connect.sh

#!/bin/bash

set -e -o pipefail

if [[ "$#" -ne 1 && "$#" -ne 2 ]]; then
    echo "Usage: $(basename $0) subdomain.domain.tld [github_username]"
    exit 1
fi

SCRIPT_DIRECTORY=$(dirname $0)

NODE_DOMAIN=$1
#RELAY_SUBDOMAIN=""


if [[ -f "$SCRIPT_DIRECTORY/settings_field_node.yml" ]]; then
    RELAY_SUBDOMAIN=$(cat $SCRIPT_DIRECTORY/settings_field_node.yml | grep "manager_domain_name" | perl -lape 's/(.*):\s*(\S*)/$2/g')
    RELAY_DOMAIN=$(cat $SCRIPT_DIRECTORY/settings_field_node.yml | grep "^domain_name" | perl -lape 's/(.*):\s*(\S*)/$2/g')

    # append the relay domain if only the node name is given
    if [[ ! -z "$RELAY_DOMAIN" ]] && [[ -z "$(echo $1 | grep ${RELAY_DOMAIN})" ]]; then
        echo "foo"
        NODE_DOMAIN="$NODE_DOMAIN.$RELAY_DOMAIN"
    fi
else
    MATCHED_BASE_DOMAIN="$(echo $1 | rev | perl -lape 's/^(\w+\.[^\.\/]+)\.(.*)/$1/g' | rev)"
    MATCHED_SUB_DOMAIN="$(echo $1 | rev | perl -lape 's/^(\w+\.[^\.\/]+)\.(.*)/$2/g' | rev)"

    if [[ "$MATCHED_BASE_DOMAIN" == "$MATCHED_SUB_DOMAIN" ]]; then
        echo "Looks like only the node name, '$MATCHED_SUB_DOMAIN', was given, but the base domain is unknown."
        echo "The base domain should be included, or 'manager_domain_name' should be present in: $SCRIPT_DIRECTORY/settings_field_node.yml"
        exit 1
    else
        # infer relay domain from base domain if yml file is not present 
        # This assumes it is on the same IP as the base domain, which is not necessarily the case.
        RELAY_SUBDOMAIN="${MATCHED_BASE_DOMAIN}"
        NODE_DOMAIN="${MATCHED_SUB_DOMAIN}.${MATCHED_BASE_DOMAIN}"
    fi
fi

CONNECT_USERNAME=""
if [[ ! -z "$2" && "$2" != " " ]]; then
    CONNECT_USERNAME=$2
else
    CONNECT_USERNAME="$(whoami)"
fi

# get the IP of the manager node
# use the AWS nameserver to ensure most current DNS records
MANAGER_IP=$(dig A +short $RELAY_SUBDOMAIN @ns-491.awsdns-61.com)

# get the port from the DNS TXT record for this subdomain
# use the AWS nameserver to ensure most current DNS records
PORT_ON_RELAY=$(dig TXT +short $NODE_DOMAIN @ns-491.awsdns-61.com | perl -lape 's/^"P(?<port_num>[0-9]+).*"/$+{port_num}/g')

if [[ -z "$PORT_ON_RELAY" || "$PORT_ON_RELAY" == " " ]]; then
        echo "The TXT record for the subdomain specified does begin have a ^PNNN; ... entry"
        exit 1
fi

echo "Connecting to '$NODE_DOMAIN' via local port '$PORT_ON_RELAY' on relay '$RELAY_SUBDOMAIN'"
echo ""
echo "Note: a live reverse tunnel must be present between '$NODE_DOMAIN' and '$RELAY_SUBDOMAIN'"
echo "      binding the SSH port of '$NODE_DOMAIN' to the local port '$PORT_ON_RELAY' on '$RELAY_SUBDOMAIN.'"
echo ""

echo "ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR -o ProxyCommand=\"ssh -W %h:%p $CONNECT_USERNAME@$MANAGER_IP\" $CONNECT_USERNAME@localhost -p $PORT_ON_RELAY"
ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR -o ProxyCommand="ssh -W %h:%p $CONNECT_USERNAME@$MANAGER_IP" $CONNECT_USERNAME@localhost -p "$PORT_ON_RELAY"