Bash array join

ip_list_with_ports.sh

# turns a port and an IP array into a string like: "127.0.0.1:4430,10.33.0.6:4430"
function ip_list_with_ports {
  local port=$1
  shift 1
  local ips=("$@")
  for ((i=0; i<${#ips[@]}; i++)); do
    echo -n "${ips[$i]}:$port"
    if [ $i != $(( ${#ips[@]} - 1 )) ]; then
      echo -n ","
    fi
  done
}

# usage
ip_list_with_ports 4430 ${node_ips[@]}