Updated to support python2.6 and python2.7; added a simple test

Author: cnelson

.gitignore

@@ -1,3 +1,5 @@
 build
 dist
 *.egg*
+*.pyc
+.tox

nsenter/__init__.py

@@ -9,7 +9,10 @@
 import os
 import logging
 from pathlib import Path
-from contextlib import ExitStack
+try:
+    from contextlib import ExitStack
+except ImportError:
+    from contextlib2 import ExitStack
 
 NAMESPACE_NAMES = frozenset('mnt ipc net pid user uts'.split())
 
@@ -18,22 +21,24 @@
 libc = ctypes.CDLL('libc.so.6')
 
 
-def nsfd(process: str, ns_type: str) -> Path:
+def nsfd(process, ns_type):
     """
     Returns the namespace file descriptor for process (self or PID) and namespace type
     """
     return Path('/proc') / str(process) / 'ns' / ns_type
+nsfd.__annotations__ = {'process': str, 'ns_type': str, 'return': Path}
 
-
-class Namespace:
-    def __init__(self, pid: str, ns_type: str):
+class Namespace(object):
+    def __init__(self, pid, ns_type):
         self.pid = pid
         self.ns_type = ns_type
         self.parent_fd = nsfd('self', ns_type).open()
         self.parent_fileno = self.parent_fd.fileno()
         self.target_fd = nsfd(pid, ns_type).open()
         self.target_fileno = self.target_fd.fileno()
 
+    __init__.__annotations__  = {'pid': str, 'ns_type': str}
+
     def __enter__(self):
         log.debug('Entering %s namespace %s', self.ns_type, self.pid)
         libc.setns(self.target_fileno, 0)
@@ -53,7 +58,7 @@ def main():
     parser.add_argument('--target', '-t', required=True, metavar='PID',
                         help='Specify a target process to get contexts from.')
     for ns in NAMESPACE_NAMES:
-        parser.add_argument('--{}'.format(ns), action='store_true', help='Enter the {} namespace'.format(ns))
+        parser.add_argument('--{0}'.format(ns), action='store_true', help='Enter the {0} namespace'.format(ns))
     parser.add_argument('--all', action='store_true', help='Enter all namespaces')
     parser.add_argument('command', nargs='*', default=['/bin/sh'])
 
@@ -68,6 +73,5 @@ def main():
             stack.enter_context(ns)
         os.execl(args.command[0], *args.command)
 
-
 if __name__ == '__main__':
     main()

setup.py

@@ -25,12 +25,16 @@ def setup_package():
         classifiers=[
             'Development Status :: 4 - Beta',
             'Programming Language :: Python',
+            'Programming Language :: Python :: 2',
+            'Programming Language :: Python :: 2.6',
+            'Programming Language :: Python :: 2.7',
+            'Programming Language :: Python :: 3',
             'Programming Language :: Python :: 3.4',
             'Programming Language :: Python :: Implementation :: CPython',
             'Operating System :: POSIX :: Linux',
             'License :: OSI Approved :: Apache Software License'],
         test_suite='tests',
-        setup_requires=['flake8'],
+        setup_requires=['flake8', 'pathlib', 'contextlib2', 'argparse'],
         packages=setuptools.find_packages(exclude=['tests', 'tests.*']),
         entry_points={'console_scripts': ['nsenter = nsenter:main']}
     )

tests.py

@@ -0,0 +1,25 @@
+import unittest
+
+import subprocess
+
+from nsenter import Namespace, NAMESPACE_NAMES 
+
+class TestNamespaces(unittest.TestCase):
+
+    def setUp(self):
+        self._child = subprocess.Popen(['/bin/cat'])
+
+    def tearDown(self):
+        self._child.terminate()
+        self._child.wait()
+
+    def test_namespace(self):
+        for name in NAMESPACE_NAMES: 
+            with Namespace(self._child.pid, name):
+                assert True
+
+        pass
+
+if __name__ == '__main__':
+    unittest.main()
+

tox.ini

@@ -1,2 +1,6 @@
+[tox]
+envlist = py26,py27,py31,py32,py33,py34
+[testenv]
+commands=python setup.py test
 [flake8]
 max-line-length=120