The reason to patch QEMU is that with latest Nix, tests like "printing"
or "misc" fail because they expect the store paths to be owned by uid 0
and gid 0.
Starting with NixOS/nix@5e51ffb1c2, Nix
builds inside of a new user namespace. Unfortunately this also means
that bind-mounted store paths that are part of the derivation's inputs
are no longer owned by uid 0 and gid 0 but by uid 65534 and gid 65534.
This in turn causes things like sudo or cups to fail with errors about
insecure file permissions.
So in order to avoid that, let's make sure the VM always gets files
owned by uid 0 and gid 0 and does a no-op when doing a chmod on a store
path.
In addition, this adds a virtualisation.qemu.program option so that we
can make sure that we only use the patched version if we're *really*
running NixOS VM tests (that is, whenever we have imported
test-instrumentation.nix).
Tested against the "misc" and "printing" tests.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
... rather than ~/.xsession-errors. It might make sense to make this
the default, in order to eliminate ad hoc, uncentralised, poorly
discoverable log files.
This hopefully fixes intermittent test failures like
http://hydra.nixos.org/build/29962437
router# [ 240.128835] INFO: task mke2fs:99 blocked for more than 120 seconds.
router# [ 240.130135] Not tainted 3.18.25 #1-NixOS
router# [ 240.131110] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
assuming that these are caused by high load on the host.
This reverts commit 02b568414d.
With a5bc11f and 6353f58 in place, we really don't need this anymore.
After running about 500 VM tests on my Hydra, it still didn't improve
very much.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
We hit page allocation failures a lot at random for VM tests, in case of
my own Hydra when it comes to the installer tests. The reason for this
is that once the memory of the VM gets heavily fragmented the kernel is
unable to allocate new pages.
Setting vm.min_free_kbytes to 16MB forces the kernel to keep a minimum
of 16 MB free.
I've done some testing accross repeated runs of the installer tests with
and without vm.min_free_kbytes set. So accross 30 test runs for each
settings, all of the tests with the option being set passed while 14
tests without that sysctl option triggered page allocation failures.
Sure, running 30 tests is not a guarantee that 16MB is enough, but we'll
see how it turns out in the long run across all VM tests.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Regression introduced in f496c3cbe4.
Previously when we used security.initialRootPassword, the default
priority for this option was 1001, because it was a default value set by
the option itself.
With the mentioned commit, it is no longer an option default but a
mkDefault, which is priority 1000.
I'm setting this to 150 now, as test-instrumentation.nix is using this
for overriding other options and because I think it still makes it
possible to simple-override it, because if no priority is given, we get
priority 100.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
The attribute ‘config.systemd.services.<service-name>.runner’
generates a script that runs the service outside of systemd. This is
useful for testing, and also allows NixOS services to be used outside
of NixOS. For instance, given a configuration file foo.nix:
{ config, pkgs, ... }:
{ services.postgresql.enable = true;
services.postgresql.package = pkgs.postgresql92;
services.postgresql.dataDir = "/tmp/postgres";
}
you can build and run PostgreSQL as follows:
$ nix-build -A config.systemd.services.postgresql.runner -I nixos-config=./foo.nix
$ ./result
This will run the service's ExecStartPre, ExecStart, ExecStartPost and
ExecStopPost commands in an appropriate environment. It doesn't work
well yet for "forking" services, since it can't track the main
process. It also doesn't work for services that assume they're always
executed by root.
