Before, we'd create a separate image for each test, in
/var/tmp/systemd-test.XXXXX/rootdisk.img. Most of the images
where very similar, except that each one had some unit files installed
specifically for the test. The installation of those custom unit files
was removed in previous commits (all the unit files are always installed).
The new approach is to only create as few distinct images as possible.
We have:
default.img: the "normal" image suitable for almost all the tests
basic.img: the same as default image but doesn't mask any services
cryptsetup.img: p2 is used for encrypted /var
badid.img: /etc/machine-id is overwritten with stuff
selinux.img: with selinux added for fun and fun
and a few others:
ls -l build/test/*img
lrwxrwxrwx 1 root root 38 Mar 21 21:23 build/test/badid.img -> /var/tmp/systemd-test.PJFFeo/badid.img
lrwxrwxrwx 1 root root 38 Mar 21 21:17 build/test/basic.img -> /var/tmp/systemd-test.na0xOI/basic.img
lrwxrwxrwx 1 root root 43 Mar 21 21:18 build/test/cryptsetup.img -> /var/tmp/systemd-test.Tzjv06/cryptsetup.img
lrwxrwxrwx 1 root root 40 Mar 21 21:19 build/test/default.img -> /var/tmp/systemd-test.EscAsS/default.img
lrwxrwxrwx 1 root root 39 Mar 21 21:22 build/test/nspawn.img -> /var/tmp/systemd-test.HSebKo/nspawn.img
lrwxrwxrwx 1 root root 40 Mar 21 21:20 build/test/selinux.img -> /var/tmp/systemd-test.daBjbx/selinux.img
lrwxrwxrwx 1 root root 39 Mar 21 21:21 build/test/test08.img -> /var/tmp/systemd-test.OgnN8Z/test08.img
I considered trying to use the same image everywhere. It would probably be
possible, but it would be very brittle. By using separate images where it is
necessary we keep various orthogonal modifications independent.
The way that images are cached is complicated by the fact that we still
want to keep them in /var/tmp. Thus, an image is created on first use and
linked to from build/test/ so it can be found by other tests.
Tests cannot be run in parallel. I think that is an acceptable limitation.
Creation of the images was probably taking more resources then the actual
tests, so we should be better off anyway.
We had an fstab for the sole purpose of remounting "/" rw. Mounting root ro
is a pointless excercise in obsolete approaches. More importantly, the nspawn
image is now the same as the qemu one.
The two timezone files are now installed in the global setup. I am not too
happy about this, but it still seems better than to create a completely
separate image just for this.
I picked the list of zone files to install by grepping through the code. This
is is a bit brittle, but installing all of them takes a while, and more
importantly, writes a lot of lines to the log.
The kernel does not sanitize /proc/cmdline. E.g. when running under qemu, it is
easy to pass a string with newline by mistake. We use read_one_line_file(), so
we would read only the first list of the file, and
write_string_file(WRITE_STRING_FILE_VERIFY_ON_FAILURE) would fail because the
target file is obviously different. Change to a kernel-generated file to avoid
the issue.
v2:
- use /proc/version instead of /proc/uptime for attempted writes, so the test
test passes even if test_write_string_file_verify() takes more than 10 ms ;]
Sometimes the test would fail there, nondeterministically. I'm not sure why,
but relying on PID1 not caching the file is clearly very brittle. Let's instead
call daemon-reload.
