selftest/target/__init__.py

   1 # target.py -- Targets
   2 # Copyright (C) 2012 Jelmer Vernooij <jelmer@samba.org>
   3 #
   4 # This program is free software; you can redistribute it and/or
   5 # modify it under the terms of the GNU General Public License
   6 # as published by the Free Software Foundation; version 3
   7 # of the License or (at your option) any later version of
   8 # the License.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  18 # MA  02110-1301, USA.
  19
  20 """Selftest target management."""
  21
  22 __all__ = ['Target', 'Environment', 'EnvironmentManager']
  23
  24
  25 class EnvironmentDown(Exception):
  26     """Indicates an environment has gone down."""
  27
  28     def __init__(self, msg):
  29         super(EnvironmentDown, self).__init__("environment went down: %s" % msg)
  30
  31
  32 class UnsupportedEnvironment(Exception):
  33     """Indicates a particular environment is not supported."""
  34
  35     def __init__(self, target, envname):
  36         super(UnsupportedEnvironment, self).__init__(
  37             "Target %s does not support environment %s" % (target, envname))
  38
  39
  40 class Target(object):
  41     """A target for Samba tests."""
  42
  43     def setup_env(self, name, prefix):
  44         """Setup an environment.
  45
  46         :param name: name of the environment
  47         :param prefix: directory to create it in
  48         """
  49         raise NotImplementedError(self.setup_env)
  50
  51
  52 class Environment(object):
  53     """An environment for Samba tests.
  54
  55     Tests often need to run against a server with particular things set up,
  56     a "environment". This environment is provided by the test target.
  57     """
  58
  59     def check(self):
  60         """Check if this environment is still up and running.
  61
  62         :return: Boolean indicating whether environment is still running
  63         """
  64         raise NotImplementedError(self.check)
  65
  66     def get_log(self):
  67         """Retrieve the last log for this environment.
  68
  69         :return: String with log
  70         """
  71         raise NotImplementedError(self.get_log)
  72
  73     def teardown(self):
  74         """Tear down an environment.
  75
  76         """
  77         raise NotImplementedError(self.teardown)
  78
  79     def get_vars(self):
  80         """Retrieve the environment variables for this environment.
  81
  82         :return: Dictionary with string -> string values
  83         """
  84         raise NotImplementedError(self.get_vars)
  85
  86
  87 class NoneEnvironment(Environment):
  88     """Empty environment.
  89     """
  90
  91     def check(self):
  92         return True
  93
  94     def get_log(self):
  95         return ""
  96
  97     def teardown(self):
  98         return
  99
 100     def get_vars(self):
 101         return {}
 102
 103
 104 class NoneTarget(Target):
 105     """Target that can only provide the 'none' environment."""
 106
 107     name = "none"
 108
 109     def setup_env(self, envname, prefix):
 110         raise UnsupportedEnvironment(self.name, envname)
 111
 112
 113 class EnvironmentManager(object):
 114     """Manager of environments."""
 115
 116     def __init__(self, target):
 117         self.target = target
 118         self.running_envs = {}
 119
 120     def get_running_env(self, name):
 121         envname = name.split(":")[0]
 122         if envname == "none":
 123             return NoneEnvironment()
 124         return self.running_envs.get(envname)
 125
 126     def getlog_env(self, envname):
 127         env = self.get_running_env(envname)
 128         return env.get_log()
 129
 130     def check_env(self, envname):
 131         """Check if an environment is still up.
 132
 133         :param envname: Environment to check
 134         """
 135         env = self.get_running_env(envname)
 136         return env.check()
 137
 138     def teardown_env(self, envname):
 139         """Tear down an environment.
 140
 141         :param envname: Name of the environment
 142         """
 143         env = self.get_running_env(envname)
 144         env.teardown()
 145         del self.running_envs[envname]
 146
 147     def teardown_all(self):
 148         """Teardown all environments."""
 149         for env in self.running_envs.iterkeys():
 150             self.teardown_env(env)
 151
 152     def setup_env(self, envname, prefix):
 153         running_env = self.get_running_env(envname)
 154         if running_env is not None:
 155             if not running_env.check():
 156                 raise EnvironmentDown(running_env.get_log())
 157             return running_env
 158
 159         env = self.target.setup_env(envname, prefix)
 160         if env is None:
 161             return None
 162
 163         self.running_envs[envname] = env
 164
 165         return env