+class FQDNEnvironmentMixin(Environment):
+ """A mixin that sets the host's FQDN to its constructor argument."""
+
+ def __init__(self, fqdn, **kw):
+ super(FQDNEnvironmentMixin, self).__init__(**kw)
+ self.COMPUTED_KEYS += ['fqdn']
+ self.__fqdn = fqdn
+
+ def get_fqdn(self):
+ """Return the fully-qualified domain name for this host.
+
+ Return None if it is unavailable or unwanted."""
+
+ return self.__fqdn
+
+
+class ConfigFQDNEnvironmentMixin(
+ ConfigEnvironmentMixin,
+ FQDNEnvironmentMixin,
+ ):
+ """Read the FQDN from the config."""
+
+ def __init__(self, config, **kw):
+ fqdn = config.get('fqdn')
+ super(ConfigFQDNEnvironmentMixin, self).__init__(
+ config=config,
+ fqdn=fqdn,
+ **kw
+ )
+
+
+class ComputeFQDNEnvironmentMixin(FQDNEnvironmentMixin):
+ """Get the FQDN by calling socket.getfqdn()."""
+
+ def __init__(self, **kw):
+ super(ComputeFQDNEnvironmentMixin, self).__init__(
+ fqdn=socket.getfqdn(),
+ **kw
+ )
+
+