1# Copyright 2016 The Chromium OS Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5"""This module provides utility functions to get the servers used by Autotest
6system, from server database or global config. The standalone module is needed
7to avoid circular imports.
8
9"""
10
11import copy
12
13import common
14from autotest_lib.client.common_lib import global_config
15from autotest_lib.client.common_lib import utils
16from autotest_lib.scheduler import scheduler_config
17from autotest_lib.site_utils import server_manager_utils
18
19
20def get_drones():
21    """Get a list of drones from server database or global config.
22    """
23    if server_manager_utils.use_server_db():
24        return server_manager_utils.get_drones()
25    else:
26        drones = global_config.global_config.get_config_value(
27                scheduler_config.CONFIG_SECTION, 'drones', default='localhost')
28        return [hostname.strip() for hostname in drones.split(',')]
29
30
31def get_shards():
32    """Get a list of shards from server database or global config.
33    """
34    if server_manager_utils.use_server_db():
35        return server_manager_utils.get_shards()
36    else:
37        config = global_config.global_config
38        shards = config.get_config_value(
39                'SERVER', 'shards', default='')
40        return [hostname.strip() for hostname in shards.split(',')]
41
42
43class DroneCache(object):
44    """A cache object to store drone list related data.
45
46    The cache is added to avoid repeated calls from each agent task. The cache
47    should be refreshed every tick.
48    """
49
50    # A cache of unrestricted drones.
51    unrestricted_drones = None
52
53    # A cache of a dict of (drone, ip).
54    drone_ip_map = None
55
56    @classmethod
57    def refresh(cls, restricted_subnets=utils.RESTRICTED_SUBNETS):
58        """Refresh the cache.
59
60        @param restricted_subnets: A list of restricted subnet, default is set
61                to restricted_subnets in global config.
62        """
63        new_drone_ip_map = {}
64        new_unrestricted_drones = []
65        for drone in get_drones():
66            new_drone_ip_map[drone] = utils.get_ip_address(drone)
67            if (not restricted_subnets or
68                not utils.get_restricted_subnet(new_drone_ip_map[drone],
69                                                restricted_subnets)):
70                new_unrestricted_drones.append(drone)
71        cls.drone_ip_map = new_drone_ip_map
72        cls.unrestricted_drones = new_unrestricted_drones
73
74
75    @classmethod
76    def get_unrestricted_drones(
77                cls, restricted_subnets=utils.RESTRICTED_SUBNETS):
78        """Get a list of cached unrestricted drones.
79
80        @param restricted_subnets: A list of restricted subnet, default is set
81                to restricted_subnets in global config.
82        """
83        if not cls.unrestricted_drones:
84            cls.refresh(restricted_subnets)
85
86        return copy.copy(cls.unrestricted_drones)
87
88
89    @classmethod
90    def get_drone_ip_map(cls, restricted_subnets=utils.RESTRICTED_SUBNETS):
91        """Get a dict of (drone, ip).
92
93        @param restricted_subnets: A list of restricted subnet, default is set
94                to restricted_subnets in global config.
95        """
96        if not cls.drone_ip_map:
97            cls.refresh(restricted_subnets)
98
99        return copy.copy(cls.drone_ip_map)
100