send_api_cmd() {
    if [ -z $PORT ]; then
        PORT=8083
    fi
    if [ -z $USER ]; then
        USER=admin
    fi

    auth="user=$USER&password=$PASSWORD&returncode=yes"
    cmd="cmd=$1"
    args="arg1=$2&arg2=$3&arg3=$4&arg4=$5&arg5=$6&arg6=$7&arg7=$8&arg8=$9"
    answer=$(curl -s -k --data "$auth&$cmd&$args" https://$HOST:$PORT/api/)
    if [ "$answer" != '0' ]; then
        return 1
    else
        return 0
    fi
}

send_ssh_cmd() {
    if [ -z $PORT ]; then
        PORT=22
    fi
    if [ -z $USER ]; then
        USER=admin
    fi
    if [ -z "$IDENTITY_FILE" ] && [ "$USER" = 'root' ]; then
        IDENTITY_FILE="/root/.ssh/id_rsa"
    fi
    if [ -z "$IDENTITY_FILE" ]; then
        IDENTITY_FILE="/home/$USER/.ssh/id_rsa"
    fi

    if [ "$USER" = 'root' ]; then
        args="$VESTA/bin/$1 \"$2\" \"$3\" \"$4\" \"$5\""
    else
        args="sudo $VESTA/bin/$1 \"$2\" \"$3\" \"$4\" \"$5\""
    fi
    ssh -i $IDENTITY_FILE $USER@$HOST -p $PORT "$args" > /dev/null 2>&1
    if [ "$?" -ne '0' ]; then
        return 1
    else
        return 0
    fi
}

scp_cmd() {
    if [ -z $PORT ]; then
        PORT=22
    fi
    if [ -z $USER ]; then
        USER=admin
    fi
    if [ -z "$IDENTITY_FILE" ]; then
        IDENTITY_FILE="/home/admin/.ssh/id_rsa"
    fi
    scp -P $PORT -i $IDENTITY_FILE $1 $USER@$HOST:$2 > /dev/null 2>&1
    if [ "$?" -ne '0' ]; then
        return 1
    else
        return 0
    fi
}

is_dnshost_new() {
    if [ -e "$VESTA/conf/dns-cluster.conf" ]; then
        check_host=$(grep "HOST='$host'" $VESTA/conf/dns-cluster.conf)
        if [ ! -z "$check_host" ]; then
            echo "Error: dns host $host exists"
            log_event "$E_EXISTS" "$EVENT"
            exit $E_EXISTS
        fi
    fi
}

is_dnshost_alive() {
    HOST=$host
    PORT=$port
    USER=$user
    PASSWORD=$password

    # Switch on connection type
    case $type in
        ssh) send_cmd="send_ssh_cmd" ;;
        *)  send_cmd="send_api_cmd" ;;
    esac

    # Check host connection
    $send_cmd v-list-sys-config
    if [ $? -ne 0 ]; then
        echo "Error: $type connection to $HOST failed"
        log_event "$E_CONNECT $EVENT"
        exit $E_CONNECT
    fi

    # Check recipient dns user
    if [ -z "$DNS_USER" ]; then
        DNS_USER='dns-cluster'
    fi
    if [ ! -z "$verbose" ]; then
        echo "DNS_USER: $DNS_USER"
    fi
    $send_cmd v-list-user $DNS_USER
    if [ $? -ne 0 ]; then
        echo "Error: dns user $DNS_USER doesn't exist"
        log_event "$E_NOTEXIST $EVENT"
        exit $E_NOTEXIST
    fi
}