core: Look up live user from PKEXEC_UID

anaconda can be run as gnome-initial-setup or liveuser on live
images, depending on how its started by the use.

It currently assumes it will be started as liveuser always.

This commit makes it look up the username and home directory by
querying PKEXEC_UID environment variable.

Resolves: rhbz#2235728

pyanaconda/core/live_user.py

@@ -19,11 +19,14 @@
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 #
 
+import os
 from collections import namedtuple
-from pwd import getpwnam
+from pwd import getpwuid
 
+from pyanaconda.anaconda_loggers import get_module_logger
 from pyanaconda.core.configuration.anaconda import conf
 
+log = get_module_logger(__name__)
 
 User = namedtuple("User", ["name", "uid", "env_add", "env_prune"])
 
@@ -37,18 +40,32 @@ def get_live_user():
  if not conf.system.provides_liveuser:
  return None
 
+ if "PKEXEC_UID" not in os.environ:
+ return None
+
+ pkexec_value = os.environ.get("PKEXEC_UID")
+
  try:
- username = "liveuser"
- uid = getpwnam(username).pw_uid
- env_prune = ("GDK_BACKEND",)
- env_add = {
- "XDG_RUNTIME_DIR": "/run/user/{}".format(uid),
- "USER": username,
- "HOME": "/home/{}".format(username),
- }
- return User(name=username,
- uid=uid,
- env_add=env_add,
- env_prune=env_prune)
+ uid = int(pkexec_value)
+ except ValueError:
+ log.error("Wrong UID obtained from system '%s'", pkexec_value)
+ return None
+
+ try:
+ passwd_entry = getpwuid(uid)
  except KeyError:
+ log.error("Can't obtain user information from pkexec UID: '%s'", pkexec_value)
  return None
+
+ username = passwd_entry.pw_name
+ home_dir = passwd_entry.pw_dir
+ env_prune = ("GDK_BACKEND",)
+ env_add = {
+ "XDG_RUNTIME_DIR": "/run/user/{}".format(uid),
+ "USER": username,
+ "HOME": home_dir,
+ }
+ return User(name=username,
+ uid=uid,
+ env_add=env_add,
+ env_prune=env_prune)

tests/unit_tests/pyanaconda_tests/core/test_live_user.py

@@ -25,16 +25,20 @@
 class GetLiveUserTests(TestCase):
 
  @patch("pyanaconda.core.live_user.conf")
- @patch("pyanaconda.core.live_user.getpwnam")
- def test_get_live_user(self, getpwnam_mock, conf_mock):
+ @patch("pyanaconda.core.live_user.getpwuid")
+ def test_get_live_user_not_on_live(self, getpwuid_mock, conf_mock):
  # not live = early exit
  conf_mock.system.provides_liveuser = False
  assert get_live_user() is None
- getpwnam_mock.assert_not_called()
+ getpwuid_mock.assert_not_called()
 
+ @patch("pyanaconda.core.live_user.conf")
+ @patch("pyanaconda.core.live_user.getpwuid")
+ @patch.dict("pyanaconda.core.live_user.os.environ", {"PKEXEC_UID": "1024"})
+ def test_get_live_user(self, getpwuid_mock, conf_mock):
  # live and has user
  conf_mock.system.provides_liveuser = True
- getpwnam_mock.return_value = Mock(pw_uid=1024)
+ getpwuid_mock.return_value = Mock(pw_uid=1024, pw_dir='/home/liveuser', pw_name='liveuser')
  assert get_live_user() == User(name="liveuser",
  uid=1024,
  env_prune=("GDK_BACKEND",),
@@ -43,10 +47,52 @@ def test_get_live_user(self, getpwnam_mock, conf_mock):
  "USER": "liveuser",
  "HOME": "/home/liveuser",
  })
- getpwnam_mock.assert_called_once_with("liveuser")
- getpwnam_mock.reset_mock()
+ getpwuid_mock.assert_called_once_with(1024)
+ getpwuid_mock.reset_mock()
+
+ @patch("pyanaconda.core.live_user.conf")
+ @patch("pyanaconda.core.live_user.getpwuid")
+ @patch.dict("pyanaconda.core.live_user.os.environ", {"PKEXEC_UID": "1024"})
+ def test_get_live_user_with_failed_getpwuid(self, getpwuid_mock, conf_mock):
+ # supposedly live but missing user
+ conf_mock.system.provides_liveuser = True
+ getpwuid_mock.side_effect = KeyError
+ assert get_live_user() is None
+ getpwuid_mock.assert_called_once_with(1024)
+
+ @patch("pyanaconda.core.live_user.conf")
+ @patch("pyanaconda.core.live_user.getpwuid")
+ @patch.dict("pyanaconda.core.live_user.os.environ", dict())
+ def test_get_live_user_with_missing_pkexec_env(self, getpwuid_mock, conf_mock):
+ # supposedly live but missing user
+ conf_mock.system.provides_liveuser = True
+ assert get_live_user() is None
+ getpwuid_mock.assert_not_called()
+
+ @patch("pyanaconda.core.live_user.conf")
+ @patch.dict("pyanaconda.core.live_user.os.environ", {"PKEXEC_UID": ""})
+ def test_get_live_user_with_empty_pkexec_env(self, conf_mock):
+ # supposedly live but missing user
+ conf_mock.system.provides_liveuser = True
+ assert get_live_user() is None
+
+ @patch("pyanaconda.core.live_user.conf")
+ @patch.dict("pyanaconda.core.live_user.os.environ", {"PKEXEC_UID": "hello world"})
+ def test_get_live_user_with_text_pkexec_env(self, conf_mock):
+ # supposedly live but missing user
+ conf_mock.system.provides_liveuser = True
+ assert get_live_user() is None
 
+ @patch("pyanaconda.core.live_user.conf")
+ @patch.dict("pyanaconda.core.live_user.os.environ", {"PKEXEC_UID": "-1"})
+ def test_get_live_user_with_negative_pkexec_env(self, conf_mock):
  # supposedly live but missing user
- getpwnam_mock.side_effect = KeyError
+ conf_mock.system.provides_liveuser = True
+ assert get_live_user() is None
+
+ @patch("pyanaconda.core.live_user.conf")
+ @patch.dict("pyanaconda.core.live_user.os.environ", {"PKEXEC_UID": "999999999999999999999999"})
+ def test_get_live_user_with_high_pkexec_env(self, conf_mock):
+ # supposedly live but missing user
+ conf_mock.system.provides_liveuser = True
  assert get_live_user() is None
- getpwnam_mock.assert_called_once_with("liveuser")