If sh is not bash, some builtin command behave slightly differently.
E.g. if sh is provided by busybox, its builtin test command does not check if
the path is a mount point or not, and 'test -w' only checks the access mode of
the inode. So, even if a readonly filesystem is mounted on a directory,
the test command may succeed.
To avoid such confusion, let's unconditionally use bash.
We want to retain *some* of the full paths in order to test more code paths.
But the default should be to use the command name only. This makes the tests
less visually cluttered.
When starting a service with a non-root user and a SystemCallFilter and
other settings (like ProtectClock), the no_new_privs flag should not be set.
Also, test that CapabilityBoundingSet behaves correctly, since we need
to preserve some capabilities to do the seccomp filter and restore the
ones set by the service before executing.
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Iago López Galeiras