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# -*- coding: utf-8 -*-
#
# This file is part of Glances.
#
# Copyright (C) 2018 Nicolargo <nicolas@nicolargo.com>
#
# Glances is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Glances is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Manage autodiscover Glances server (thk to the ZeroConf protocol)."""
import socket
import sys
from glances.globals import BSD
from glances.logger import logger
try:
from zeroconf import (
__version__ as __zeroconf_version,
ServiceBrowser,
ServiceInfo,
Zeroconf
)
zeroconf_tag = True
except ImportError:
zeroconf_tag = False
# Zeroconf 0.17 or higher is needed
if zeroconf_tag:
zeroconf_min_version = (0, 17, 0)
zeroconf_version = tuple([int(num) for num in __zeroconf_version.split('.')])
logger.debug("Zeroconf version {} detected.".format(__zeroconf_version))
if zeroconf_version < zeroconf_min_version:
logger.critical("Please install zeroconf 0.17 or higher.")
sys.exit(1)
# Global var
# Recent versions of the zeroconf python package doesnt like a zeroconf type that ends with '._tcp.'.
# Correct issue: zeroconf problem with zeroconf_type = "_%s._tcp." % 'glances' #888
zeroconf_type = "_%s._tcp.local." % 'glances'
class AutoDiscovered(object):
"""Class to manage the auto discovered servers dict."""
def __init__(self):
# server_dict is a list of dict (JSON compliant)
# [ {'key': 'zeroconf name', ip': '172.1.2.3', 'port': 61209, 'cpu': 3, 'mem': 34 ...} ... ]
self._server_list = []
def get_servers_list(self):
"""Return the current server list (list of dict)."""
return self._server_list
def set_server(self, server_pos, key, value):
"""Set the key to the value for the server_pos (position in the list)."""
self._server_list[server_pos][key] = value
def add_server(self, name, ip, port):
"""Add a new server to the list."""
new_server = {
'key': name, # Zeroconf name with both hostname and port
'name': name.split(':')[0], # Short name
'ip': ip, # IP address seen by the client
'port': port, # TCP port
'username': 'glances', # Default username
'password': '', # Default password
'status': 'UNKNOWN', # Server status: 'UNKNOWN', 'OFFLINE', 'ONLINE', 'PROTECTED'
'type': 'DYNAMIC'} # Server type: 'STATIC' or 'DYNAMIC'
self._server_list.append(new_server)
logger.debug("Updated servers list (%s servers): %s" %
(len(self._server_list), self._server_list))
def remove_server(self, name):
"""Remove a server from the dict."""
for i in self._server_list:
if i['key'] == name:
try:
self._server_list.remove(i)
logger.debug("Remove server %s from the list" % name)
logger.debug("Updated servers list (%s servers): %s" % (
len(self._server_list), self._server_list))
except ValueError:
logger.error(
"Cannot remove server %s from the list" % name)
class GlancesAutoDiscoverListener(object):
"""Zeroconf listener for Glances server."""
def __init__(self):
# Create an instance of the servers list
self.servers = AutoDiscovered()
def get_servers_list(self):
"""Return the current server list (list of dict)."""
return self.servers.get_servers_list()
def set_server(self, server_pos, key, value):
"""Set the key to the value for the server_pos (position in the list)."""
self.servers.set_server(server_pos, key, value)
def add_service(self, zeroconf, srv_type, srv_name):
"""Method called when a new Zeroconf client is detected.
Return True if the zeroconf client is a Glances server
Note: the return code will never be used
"""
if srv_type != zeroconf_type:
return False
logger.debug("Check new Zeroconf server: %s / %s" %
(srv_type, srv_name))
info = zeroconf.get_service_info(srv_type, srv_name)
if info:
new_server_ip = socket.inet_ntoa(info.address)
new_server_port = info.port
# Add server to the global dict
self.servers.add_server(srv_name, new_server_ip, new_server_port)
logger.info("New Glances server detected (%s from %s:%s)" %
(srv_name, new_server_ip, new_server_port))
else:
logger.warning(
"New Glances server detected, but Zeroconf info failed to be grabbed")
return True
def remove_service(self, zeroconf, srv_type, srv_name):
"""Remove the server from the list."""
self.servers.remove_server(srv_name)
logger.info(
"Glances server %s removed from the autodetect list" % srv_name)
class GlancesAutoDiscoverServer(object):
"""Implementation of the Zeroconf protocol (server side for the Glances client)."""
def __init__(self, args=None):
if zeroconf_tag:
logger.info("Init autodiscover mode (Zeroconf protocol)")
try:
self.zeroconf = Zeroconf()
except socket.error as e:
logger.error("Cannot start Zeroconf (%s)" % e)
self.zeroconf_enable_tag = False
else:
self.listener = GlancesAutoDiscoverListener()
self.browser = ServiceBrowser(
self.zeroconf, zeroconf_type, self.listener)
self.zeroconf_enable_tag = True
else:
logger.error("Cannot start autodiscover mode (Zeroconf lib is not installed)")
self.zeroconf_enable_tag = False
def get_servers_list(self):
"""Return the current server list (dict of dict)."""
if zeroconf_tag and self.zeroconf_enable_tag:
return self.listener.get_servers_list()
else:
return []
def set_server(self, server_pos, key, value):
"""Set the key to the value for the server_pos (position in the list)."""
if zeroconf_tag and self.zeroconf_enable_tag:
self.listener.set_server(server_pos, key, value)
def close(self):
if zeroconf_tag and self.zeroconf_enable_tag:
self.zeroconf.close()
class GlancesAutoDiscoverClient(object):
"""Implementation of the zeroconf protocol (client side for the Glances server)."""
def __init__(self, hostname, args=None):
if zeroconf_tag:
zeroconf_bind_address = args.bind_address
try:
self.zeroconf = Zeroconf()
except socket.error as e:
logger.error("Cannot start zeroconf: {}".format(e))
# XXX *BSDs: Segmentation fault (core dumped)
# -- https://bitbucket.org/al45tair/netifaces/issues/15
if not BSD:
try:
# -B @ overwrite the dynamic IPv4 choice
if zeroconf_bind_address == '0.0.0.0':
zeroconf_bind_address = self.find_active_ip_address()
except KeyError:
# Issue #528 (no network interface available)
pass
# Check IP v4/v6
address_family = socket.getaddrinfo(zeroconf_bind_address, args.port)[0][0]
# Start the zeroconf service
self.info = ServiceInfo(
zeroconf_type, '{}:{}.{}'.format(hostname, args.port, zeroconf_type),
address=socket.inet_pton(address_family, zeroconf_bind_address),
port=args.port, weight=0, priority=0, properties={}, server=hostname)
try:
self.zeroconf.register_service(self.info)
except socket.error as e:
logger.error("Error while announcing Glances server: {}".format(e))
else:
print("Announce the Glances server on the LAN (using {} IP address)".format(zeroconf_bind_address))
else:
logger.error("Cannot announce Glances server on the network: zeroconf library not found.")
@staticmethod
def find_active_ip_address():
"""Try to find the active IP addresses."""
import netifaces
# Interface of the default gateway
gateway_itf = netifaces.gateways()['default'][netifaces.AF_INET][1]
# IP address for the interface
return netifaces.ifaddresses(gateway_itf)[netifaces.AF_INET][0]['addr']
def close(self):
if zeroconf_tag:
self.zeroconf.unregister_service(self.info)
self.zeroconf.close()