Connect to a vCenter via the API
    :param host: Hostname or IP of the vCenter
    :type host: str or unicode
    :param username: Username
    :type user: str or unicode
    :param password: Password
    :type user: str or unicode
    :param port: Port on which the vCenter API is running (default: 443)
    :type port: int
    :param verify: Whether to verify SSL certs upon connection (default: False)
    :type verify: bool
    :param debug: Debug option (default: False)
    :type debug: bool
    :return: Content
    :rtype: vim.ServiceInstanceContent

def connect(host, username, password, port=443, verify=False, debug=False):
    '''
    Connect to a vCenter via the API
    :param host: Hostname or IP of the vCenter
    :type host: str or unicode
    :param username: Username
    :type user: str or unicode
    :param password: Password
    :type user: str or unicode
    :param port: Port on which the vCenter API is running (default: 443)
    :type port: int
    :param verify: Whether to verify SSL certs upon connection (default: False)
    :type verify: bool
    :param debug: Debug option (default: False)
    :type debug: bool
    :return: Content
    :rtype: vim.ServiceInstanceContent
    '''
    context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
    if not verify:
        # Disable warnings about unsigned certificates
        context.verify_mode = ssl.CERT_NONE
        requests.packages.urllib3.disable_warnings()

    try:
        si = SmartConnect(
            host=host,
            user=username,
            pwd=password,
            port=port,
            sslContext=context
        )
        # Register auto disconnect
        atexit.register(Disconnect, si)
        # Return content
        return si.RetrieveContent()
    except IOError as e:
        print('I/O error({0}): {1}'.format(e.errno, e.strerror))
    except vmodl.MethodFault as e:
        print('Connection could not be established', file=sys.stderr)
        raise ConnectionError('Connection could not be established')
        print('Caught vmodl fault: ', e.msg, file=sys.stderr)
        if debug:
            traceback.print_exc()
    except Exception as e:
        print('Caught exception:', str(e), file=sys.stderr)
        if debug:
            traceback.print_exc()