CasperSecurity
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for L{twisted.python.systemd}.
"""
import os
from twisted.python.systemd import ListenFDs
from twisted.trial.unittest import TestCase
class InheritedDescriptorsMixin:
"""
Mixin for a L{TestCase} subclass which defines test methods for some kind of
systemd sd-daemon class. In particular, it defines tests for a
C{inheritedDescriptors} method.
"""
def test_inheritedDescriptors(self):
"""
C{inheritedDescriptors} returns a list of integers giving the file
descriptors which were inherited from systemd.
"""
sddaemon = self.getDaemon(7, 3)
self.assertEqual([7, 8, 9], sddaemon.inheritedDescriptors())
def test_repeated(self):
"""
Any subsequent calls to C{inheritedDescriptors} return the same list.
"""
sddaemon = self.getDaemon(7, 3)
self.assertEqual(
sddaemon.inheritedDescriptors(), sddaemon.inheritedDescriptors()
)
class MemoryOnlyMixin:
"""
Mixin for a L{TestCase} subclass which creates creating a fake, in-memory
implementation of C{inheritedDescriptors}. This provides verification that
the fake behaves in a compatible way with the real implementation.
"""
def getDaemon(self, start, count):
"""
Invent C{count} new I{file descriptors} (actually integers, attached to
no real file description), starting at C{start}. Construct and return a
new L{ListenFDs} which will claim those integers represent inherited
file descriptors.
"""
return ListenFDs(range(start, start + count))
class EnvironmentMixin:
"""
Mixin for a L{TestCase} subclass which creates a real implementation of
C{inheritedDescriptors} which is based on the environment variables set by
systemd. To facilitate testing, this mixin will also create a fake
environment dictionary and add keys to it to make it look as if some
descriptors have been inherited.
"""
def initializeEnvironment(self, count, pid):
"""
Create a copy of the process environment and add I{LISTEN_FDS} and
I{LISTEN_PID} (the environment variables set by systemd) to it.
"""
result = os.environ.copy()
result["LISTEN_FDS"] = str(count)
result["LISTEN_PID"] = str(pid)
return result
def getDaemon(self, start, count):
"""
Create a new L{ListenFDs} instance, initialized with a fake environment
dictionary which will be set up as systemd would have set it up if
C{count} descriptors were being inherited. The descriptors will also
start at C{start}.
"""
fakeEnvironment = self.initializeEnvironment(count, os.getpid())
return ListenFDs.fromEnvironment(environ=fakeEnvironment, start=start)
class MemoryOnlyTests(MemoryOnlyMixin, InheritedDescriptorsMixin, TestCase):
"""
Apply tests to L{ListenFDs}, explicitly constructed with some fake file
descriptors.
"""
class EnvironmentTests(EnvironmentMixin, InheritedDescriptorsMixin, TestCase):
"""
Apply tests to L{ListenFDs}, constructed based on an environment dictionary.
"""
def test_secondEnvironment(self):
"""
Only a single L{Environment} can extract inherited file descriptors.
"""
fakeEnvironment = self.initializeEnvironment(3, os.getpid())
first = ListenFDs.fromEnvironment(environ=fakeEnvironment)
second = ListenFDs.fromEnvironment(environ=fakeEnvironment)
self.assertEqual(list(range(3, 6)), first.inheritedDescriptors())
self.assertEqual([], second.inheritedDescriptors())
def test_mismatchedPID(self):
"""
If the current process PID does not match the PID in the environment, no
inherited descriptors are reported.
"""
fakeEnvironment = self.initializeEnvironment(3, os.getpid() + 1)
sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
self.assertEqual([], sddaemon.inheritedDescriptors())
def test_missingPIDVariable(self):
"""
If the I{LISTEN_PID} environment variable is not present, no inherited
descriptors are reported.
"""
fakeEnvironment = self.initializeEnvironment(3, os.getpid())
del fakeEnvironment["LISTEN_PID"]
sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
self.assertEqual([], sddaemon.inheritedDescriptors())
def test_nonIntegerPIDVariable(self):
"""
If the I{LISTEN_PID} environment variable is set to a string that cannot
be parsed as an integer, no inherited descriptors are reported.
"""
fakeEnvironment = self.initializeEnvironment(3, "hello, world")
sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
self.assertEqual([], sddaemon.inheritedDescriptors())
def test_missingFDSVariable(self):
"""
If the I{LISTEN_FDS} environment variable is not present, no inherited
descriptors are reported.
"""
fakeEnvironment = self.initializeEnvironment(3, os.getpid())
del fakeEnvironment["LISTEN_FDS"]
sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
self.assertEqual([], sddaemon.inheritedDescriptors())
def test_nonIntegerFDSVariable(self):
"""
If the I{LISTEN_FDS} environment variable is set to a string that cannot
be parsed as an integer, no inherited descriptors are reported.
"""
fakeEnvironment = self.initializeEnvironment("hello, world", os.getpid())
sddaemon = ListenFDs.fromEnvironment(environ=fakeEnvironment)
self.assertEqual([], sddaemon.inheritedDescriptors())
def test_defaultEnviron(self):
"""
If the process environment is not explicitly passed to
L{Environment.__init__}, the real process environment dictionary is
used.
"""
self.patch(os, "environ", {"LISTEN_PID": str(os.getpid()), "LISTEN_FDS": "5"})
sddaemon = ListenFDs.fromEnvironment()
self.assertEqual(list(range(3, 3 + 5)), sddaemon.inheritedDescriptors())