Merge pull request #46 from edx/cdyer/tmpdir-issue

Fix command line handling so it works when no user is specified.

codejail/jail_code.py

@@ -179,6 +179,7 @@ def jail_code(command, code=None, files=None, extra_files=None, argv=None,
         os.chmod(tmptmp, 0777)
 
         argv = argv or []
+        env = {'TMPDIR': 'tmp'}
 
         # All the supporting files are copied into our directory.
         for filename in files or ():
@@ -209,11 +210,9 @@ def jail_code(command, code=None, files=None, extra_files=None, argv=None,
         user = COMMANDS[command]['user']
         if user:
             # Run as the specified user
-            cmd.extend(['sudo', '-u', user])
+            cmd.extend(['sudo', '-u', user, 'TMPDIR=tmp'])
             rm_cmd.extend(['sudo', '-u', user])
 
-        # Point TMPDIR at our temp directory.
-        cmd.extend(['TMPDIR=tmp'])
         # Start with the command line dictated by "python" or whatever.
         cmd.extend(COMMANDS[command]['cmdline_start'])
 
@@ -232,7 +231,7 @@ def jail_code(command, code=None, files=None, extra_files=None, argv=None,
 
         # Run the subprocess.
         status, stdout, stderr = run_subprocess_fn(
-            cmd=cmd, cwd=homedir, env={}, slug=slug,
+            cmd=cmd, cwd=homedir, env=env, slug=slug,
             stdin=stdin,
             realtime=LIMITS["REALTIME"], rlimits=create_rlimits(),
             )

codejail/tests/helpers.py

+"""
+Helper code to facilitate testing
+"""
+
+from contextlib import contextmanager
+
+from codejail import jail_code
+
+SAME = object()
+
+
+@contextmanager
+def override_configuration(command, bin_path, user):
+    """
+    Context manager to temporarily alter the configuration of a codejail
+    command.
+    """
+    old = jail_code.COMMANDS.get(command)
+    if bin_path is SAME:
+        bin_path = old['cmdline_start'][0]
+    if user is SAME:
+        user = old['user']
+    try:
+        jail_code.configure(command, bin_path, user)
+        yield
+    finally:
+        if old is None:
+            del jail_code.COMMANDS[command]
+        else:
+            jail_code.COMMANDS[command] = old

codejail/tests/test_jail_code.py

 """Test jail_code.py"""
 
-import json
 import logging
 import os
 import os.path
 import shutil
 import signal
-import textwrap
+import sys
 import tempfile
+import textwrap
 import time
 import unittest
 
@@ -16,6 +16,7 @@ from nose.plugins.skip import SkipTest
 
 from codejail.jail_code import jail_code, is_configured, set_limit, LIMITS
 from codejail import proxy
+from . import helpers
 
 
 def jailpy(code=None, *args, **kwargs):
@@ -44,8 +45,8 @@ def text_of_logs(mock_calls):
 
     """
     text = ""
-    for m in mock_calls:
-        level, msg, args = m[1]
+    for call in mock_calls:
+        level, msg, args = call[1]
         msg_formatted = msg % args
         text += "%s: %s\n" % (logging.getLevelName(level), msg_formatted)
     return text
@@ -74,6 +75,13 @@ class TestFeatures(JailCodeHelpers, unittest.TestCase):
         self.assertResultOk(res)
         self.assertEqual(res.stdout, 'Hello, world!\n')
 
+    def test_hello_world_without_user(self):
+        # The default jail executable might not grant execute permission to the
+        # current user, but we know the current python executable does, so use
+        # that to test userless execution.
+        with helpers.override_configuration("python", bin_path=sys.executable, user=None):
+            self.test_hello_world()
+
     def test_argv(self):
         res = jailpy(
             code="import sys; print ':'.join(sys.argv[1:])",
@@ -227,7 +235,7 @@ class TestFeatures(JailCodeHelpers, unittest.TestCase):
 
     @mock.patch("codejail.subproc.log._log")
     def test_slugs_get_logged(self, log_log):
-        res = jailpy(code="print 'Hello, world!'", slug="HELLO")
+        jailpy(code="print 'Hello, world!'", slug="HELLO")
         log_text = text_of_logs(log_log.mock_calls)
         self.assertRegexpMatches(log_text, r"INFO: Executed jailed code HELLO in .*, with PID .*")
 

pylintrc

@@ -169,7 +169,7 @@ notes=FIXME,XXX,TODO
 [FORMAT]
 
 # Maximum number of characters on a single line.
-max-line-length=79
+max-line-length=120
 
 # Maximum number of lines in a module
 max-module-lines=1000