Restore compatibility with non-linux operating systems

This partially reverts fce48c2893 which
removes windows support along with the other non-linux operating
systems.

Some developers may run unit tests on non-linux operating systems such
as mac OS, and this avoids hard-failure in such usage.

Change-Id: Ia0deb0bce2b87df0297178c75b41f7bf065ddf2d
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

oslo_privsep/capabilities.py

@@ -14,6 +14,7 @@
 
 import enum
 import os
+import platform
 import sys
 
 import cffi
@@ -113,10 +114,17 @@ ffi = cffi.FFI()
 ffi.cdef(CDEF)
 
 
-crt = ffi.dlopen(None)
-_prctl = crt.prctl
-_capget = crt.capget
-_capset = crt.capset
+if platform.system() == 'Linux':
+    # mock.patching crt.* directly seems to upset cffi.  Use an
+    # indirection point here for easier testing.
+    crt = ffi.dlopen(None)
+    _prctl = crt.prctl
+    _capget = crt.capget
+    _capset = crt.capset
+else:
+    _prctl = None
+    _capget = None
+    _capset = None
 
 
 def set_keepcaps(enable):

oslo_privsep/daemon.py

@@ -46,11 +46,9 @@ The privsep daemon exits when the communication channel is closed,
 from concurrent import futures
 import enum
 import errno
-import fcntl
-import grp
 import logging as pylogging
 import os
-import pwd
+import platform
 import socket
 import subprocess
 import sys
@@ -70,6 +68,11 @@ from oslo_privsep._i18n import _
 from oslo_privsep import capabilities
 from oslo_privsep import comm
 
+if platform.system() == 'Linux':
+    import fcntl
+    import grp
+    import pwd
+
 LOG = logging.getLogger(__name__)
 
 

oslo_privsep/tests/test_daemon.py

@@ -17,6 +17,7 @@ import eventlet
 import fixtures
 import functools
 import logging as pylogging
+import platform
 import sys
 import time
 from unittest import mock
@@ -24,6 +25,7 @@ from unittest import mock
 from oslo_log import formatters
 from oslo_log import log as logging
 from oslotest import base
+import testtools
 
 from oslo_privsep import capabilities
 from oslo_privsep import comm
@@ -86,6 +88,8 @@ class LogRecorder(pylogging.Formatter):
         return super().format(record)
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class LogTest(testctx.TestContextTestCase):
     def test_priv_loglevel(self):
         logger = self.useFixture(fixtures.FakeLogger(
@@ -153,6 +157,8 @@ class LogTest(testctx.TestContextTestCase):
         formatter.format(record)
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class LogTestDaemonTraceback(testctx.TestContextTestCase):
     def setUp(self):
         self.config_override = {'log_daemon_traceback': True}
@@ -179,6 +185,8 @@ class LogTestDaemonTraceback(testctx.TestContextTestCase):
         self.assertEqual(logging.WARN, record.levelno)
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class DaemonTest(base.BaseTestCase):
 
     @mock.patch('os.setuid')
@@ -215,6 +223,8 @@ class DaemonTest(base.BaseTestCase):
             [])
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class WithContextTest(testctx.TestContextTestCase):
 
     def test_unexported(self):

oslo_privsep/tests/test_priv_context.py

@@ -15,12 +15,15 @@
 
 import logging
 import os
+import platform
 import shlex
 import sys
 import tempfile
 import time
 from unittest import mock
 
+import testtools
+
 from oslo_privsep import comm
 from oslo_privsep import daemon
 from oslo_privsep import priv_context
@@ -63,6 +66,8 @@ def fail(custom=False):
         raise RuntimeError("I can't let you do that Dave")
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class PrivContextTest(testctx.TestContextTestCase):
 
     def test_set_client_mode(self):
@@ -129,6 +134,8 @@ class PrivContextTest(testctx.TestContextTestCase):
         self.assertTrue(context.start_lock.__enter__.called)
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class SeparationTest(testctx.TestContextTestCase):
     def test_getpid(self):
         # Verify that priv_getpid() was executed in another process.
@@ -149,6 +156,8 @@ class SeparationTest(testctx.TestContextTestCase):
         self.assertNotMyPid(priv_getpid())
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class RootwrapTest(testctx.TestContextTestCase):
     def setUp(self):
         super().setUp()
@@ -186,6 +195,8 @@ class RootwrapTest(testctx.TestContextTestCase):
         self.assertEqual(42, res)
 
 
+@testtools.skipIf(platform.system() != 'Linux',
+                  'works only on Linux platform.')
 class SerializationTest(testctx.TestContextTestCase):
     def test_basic_functionality(self):
         self.assertEqual(43, add1(42))