Some of the code was quite confusing inside libcontainer/user, so
refactor and comment it so future maintainers can understand what's
going and what edge cases we have to deal with.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Most shadow-related tools don't treat numeric ids as potential
usernames, so change our behaviour to match that. Previously, using an
explicit specification like 111:222 could result in the UID and GID not
being 111 and 222 respectively (which is confusing).
Signed-off-by: Aleksa Sarai <asarai@suse.de>
/etc/groups is not needed when specifying numeric group ids. This
change allows containers without /etc/groups to specify numeric
supplemental groups.
Signed-off-by: Sami Wagiaalla <swagiaal@redhat.com>
Update the tests to use the test-friendly GetAdditionalGroups API,
rather than making random files for no good reason.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
The old GetAdditionalGroups* API didn't match the rest of
libcontainer/user, we make functions that take io.Readers and then make
wrappers around them. Otherwise we have to do dodgy stuff when testing
our code.
Fixes: d4ece29c0b ("refactor GetAdditionalGroupsPath")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>