Merge ~vorlon/utah/+git/utah:check-access-not-owner into utah:master

[Steve Langasek]

Pet peeve: don't make me log back into my desktop after installing your software.

[Steve Langasek (vorlon)]

assumes https://code.launchpad.net/~vorlon/utah/+git/utah/+merge/375307 as a predep.

[Paride Legovini (paride)]

Should we use config.logpath instead of hardcoding /var/log/utah?

[Steve Langasek (vorlon)]

On Fri, Nov 08, 2019 at 03:19:09PM -0000, Paride Legovini wrote:
> Should we use config.logpath instead of hardcoding /var/log/utah?

Yes, I think we should, thanks. Pushed that change.

[Paride Legovini (paride)]

Thanks!

review: Approve

diff --git a/debian/changelog b/debian/changelog
index 29d86ac..532cab7 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -9,6 +9,8 @@ utah (0.19) UNRELEASED; urgency=medium
   * Drop dependency on libvirt-bin; it's a transitional package and none of
     the binaries included in the xenial version of the package are
     referenced at all in the utah source.
+  * Don't check membership in a utah group when what we actually care about
+    is /var/log/utah being writable by the current user.
 
  -- Paride Legovini <[e-mail]>  Thu, 11 Jul 2019 11:20:10 +0200
 
diff --git a/examples/run_utah_tests.py b/examples/run_utah_tests.py
index 9677e70..489cb2e 100755
--- a/examples/run_utah_tests.py
+++ b/examples/run_utah_tests.py
@@ -27,7 +27,7 @@ import utah
 from utah.cleanup import cleanup
 from utah.config import config
 from utah.exceptions import UTAHException
-from utah.group import check_user_group, print_group_error_message
+from utah.group import check_user_writable, print_group_error_message
 from utah.iso import ISO
 from utah.parser import get_parser, parse_args  # NOQA
 from utah.provisioning.ssh import ProvisionedMachine
@@ -109,7 +109,7 @@ def run_utah_tests(argv=None):
     except SystemExit:
         sys.exit(ReturnCodes.CMD_PARSING_ERROR)
 
-    if not check_user_group():
+    if not check_user_writable():
         print_group_error_message(__file__)
         return ReturnCodes.GROUP_ERROR
 
diff --git a/utah/group.py b/utah/group.py
index a482c2a..f035c6e 100644
--- a/utah/group.py
+++ b/utah/group.py
@@ -24,19 +24,16 @@ import getpass
 from utah.config import config
 
 
-def check_user_group(group=config.group):
-    """Return whether the user is a member of the given group."""
-    user_gids = os.getgroups()
-    gid = grp.getgrnam(group).gr_gid
-
-    return gid in user_gids
+def check_user_writable(path=config.logpath):
+    """Return whether the user has write access to the given path."""
+    return os.access(path, os.W_OK)
 
 
 def print_group_error_message(script):
     """Print error message to stderr to be used by scripts."""
     argv = list(sys.argv)
     argv[0] = os.path.abspath(script)
-    message = ["Error: you are not in the utah group.",
+    message = ["Error: you do not have write access to /var/log/utah.",
                ("If you believe you have properly configured "
                 "your user account for UTAH use, try:"),
                '    sudo usermod -a -G utah {}'.format(getpass.getuser()),