Subprocess class and tests, fix some other stuff

src/netns/node.py

@@ -64,6 +64,7 @@ def _start_child(debug = False):
         s1.close()
         return (s0, pid)
 
+    # FIXME: clean up signal handers, atexit functions, etc.
     try:
         s0.close()
         srv = netns.protocol.Server(s1, debug)

src/netns/subprocess.py

@@ -76,17 +76,17 @@ def spawn(executable, argv = None, cwd = None, env = None,
             if cwd != None:
                 os.chdir(cwd)
             if not argv:
-                argv = [ file ]
-            if '/' in file: # Should not search in PATH
+                argv = [ executable ]
+            if '/' in executable: # Should not search in PATH
                 if env != None:
-                    os.execve(file, argv, env)
+                    os.execve(executable, argv, env)
                 else:
-                    os.execv(file, argv)
+                    os.execv(executable, argv)
             else: # use PATH
                 if env != None:
-                    os.execvpe(file, argv, env)
+                    os.execvpe(executable, argv, env)
                 else:
-                    os.execvp(file, argv)
+                    os.execvp(executable, argv)
             raise RuntimeError("Unreachable reached!")
         except:
             try:
@@ -119,6 +119,7 @@ def spawn(executable, argv = None, cwd = None, env = None,
     os.waitpid(pid, 0)
     exc = pickle.loads(s)
     # XXX: sys.excepthook
+    #print exc.child_traceback
     raise exc
 
 # Used to print extra info in nested exceptions
@@ -145,3 +146,44 @@ def wait(pid):
     """Wait for process to die and return the exit code."""
     return os.waitpid(pid, 0)[1]
 
+class Subprocess(object):
+    # FIXME: this is the visible interface; documentation should move here.
+    """OO-style interface to spawn(), but invoked through the controlling
+    process."""
+    # FIXME
+    default_user = None
+    def __init__(self, node, executable, argv = None, cwd = None, env = None,
+            stdin = None, stdout = None, stderr = None, user = None):
+        self._slave = node._slave
+
+        if user == None:
+            user = Subprocess.default_user
+
+        # confusingly enough, to go to the function at the top of this file,
+        # I need to call it thru the communications protocol: remember that
+        # happens in another process!
+        self._pid = self._slave.spawn(executable, argv = argv, cwd = cwd,
+                env = env, stdin = stdin, stdout = stdout, stderr = stderr,
+                user = user)
+
+        node._add_subprocess(self)
+
+    @property
+    def pid(self):
+        return self._pid
+
+    def poll(self):
+        r = self._slave.poll(self._pid)
+        if r != None:
+            del self._pid
+            self.return_value = r
+        return r
+
+    def wait(self):
+        r = self._slave.wait(self._pid)
+        del self._pid
+        self.return_value = r
+        return r
+
+    def signal(self, sig = signal.SIGTERM):
+        return self._slave.signal(self._pid, sig)

t/test_subprocess.py

@@ -54,37 +54,64 @@ class TestSubprocess(unittest.TestCase):
     # XXX: unittest still cannot skip tests
     #@unittest.skipUnless(os.getuid() == 0, "Test requires root privileges")
     @test_util.skipUnless(os.getuid() == 0, "Test requires root privileges")
-    def test_popen_chuser(self):
+    def test_spawn_chuser(self):
         user = 'nobody'
-        pid = netns.subprocess.spawn(user, '/bin/sleep', ['/bin/sleep', '100'])
+        pid = netns.subprocess.spawn('/bin/sleep', ['/bin/sleep', '100'],
+                user = user)
         self._check_ownership(user, pid)
         os.kill(pid, signal.SIGTERM)
         self.assertEquals(netns.subprocess.wait(pid), signal.SIGTERM)
 
-    def test_popen_basic(self):
+    def test_spawn_basic(self):
         # User does not exist
         self.assertRaises(ValueError, netns.subprocess.spawn,
-                self.nouser, '/bin/sleep', ['/bin/sleep', '1000'])
+                '/bin/sleep', ['/bin/sleep', '1000'], user = self.nouser)
         self.assertRaises(ValueError, netns.subprocess.spawn,
-                self.nouid, '/bin/sleep', ['/bin/sleep', '1000'])
+                '/bin/sleep', ['/bin/sleep', '1000'], user = self.nouid)
         # Invalid CWD: it is a file
         self.assertRaises(OSError, netns.subprocess.spawn,
-                None, '/bin/sleep', None, cwd = '/bin/sleep')
+                '/bin/sleep', cwd = '/bin/sleep')
         # Invalid CWD: does not exist
         self.assertRaises(OSError, netns.subprocess.spawn,
-                None, '/bin/sleep', None, cwd = self.nofile)
+                '/bin/sleep', cwd = self.nofile)
         # Exec failure
-        self.assertRaises(OSError, netns.subprocess.spawn,
-                None, self.nofile, None)
+        self.assertRaises(OSError, netns.subprocess.spawn, self.nofile)
+
         # Test that the environment is cleared: sleep should not be found
         # XXX: This should be a python bug: if I don't set PATH explicitly, it
         # uses a default search path
         self.assertRaises(OSError, netns.subprocess.spawn,
-                None, 'sleep', None, env = {'PATH': ''})
+                'sleep', env = {'PATH': ''})
         #p = netns.subprocess.spawn(None, '/bin/sleep', ['/bin/sleep', '1000'],
         #        cwd = '/', env = [])
         # FIXME: tests fds
 
+    @test_util.skipUnless(os.getuid() == 0, "Test requires root privileges")
+    def test_Subprocess_basic(self):
+        node = netns.Node()
+        # User does not exist
+        self.assertRaises(RuntimeError, netns.subprocess.Subprocess, node,
+                '/bin/sleep', ['/bin/sleep', '1000'], user = self.nouser)
+        self.assertRaises(RuntimeError, netns.subprocess.Subprocess, node,
+                '/bin/sleep', ['/bin/sleep', '1000'], user = self.nouid)
+        # Invalid CWD: it is a file
+        self.assertRaises(RuntimeError, netns.subprocess.Subprocess, node,
+                '/bin/sleep', cwd = '/bin/sleep')
+        # Invalid CWD: does not exist
+        self.assertRaises(RuntimeError, netns.subprocess.Subprocess, node,
+                '/bin/sleep', cwd = self.nofile)
+        # Exec failure
+        self.assertRaises(RuntimeError, netns.subprocess.Subprocess, node,
+                self.nofile)
+        # Test that the environment is cleared: sleep should not be found
+        # XXX: This should be a python bug: if I don't set PATH explicitly, it
+        # uses a default search path
+        self.assertRaises(RuntimeError, netns.subprocess.Subprocess, node,
+                'sleep', env = {'PATH': ''})
+        #p = netns.subprocess.Subprocess(None, '/bin/sleep', ['/bin/sleep', '1000'], cwd = '/', env = [])
+        # FIXME: tests fds
+
+
 if __name__ == '__main__':
     unittest.main()