Previous to this commit, the entire test driver environment was shared
with the actual python test environment.
This is a hefty api surface. This commit selectively exposes only those
symbols to the test environment that are actually meant to be used by
tests.
This is relevant for `nixos-build-vms(8)` which doesn't have a
test-script. In that case it's more intuitive to directly go into the
interactive mode which is IMHO more intuitive.
Previously the driver was configured exclusively through convoluted
environment variables.
Now the driver's defaults are configured through env variables.
Some additional concerns are in the github comments of this PR.
Less nesting, where that improves readability. More nesteing, where
that improves readability, but most importantly:
Expose individual functions separately so that they can be more easily
built directly, eg.:
`nix build --impure --expr '(import ./testing-python.nix {system = builtins.currentSystem;}).mkTestDriver'`
At nixpkgs root:
`rg redirectSerial ./` does not result in any other match
nor does
`rg USE_SERIAL ./` except for an unrelated match in:
pkgs/tools/graphics/argyllcms/default.nix
Bash's standard behavior of not propagating non-zero exit codes
through a pipeline is unexpected and almost universally
unwanted. Default to setting `pipefail` for the command being run;
it can still be turned off by prefixing the pipeline with
`set +o pipefail` if needed.
Also, set `errexit` and `nonunset` options to make the first command
of consecutive commands separated by `;` fail, and disallow
dereferencing unset variables respectively.
For now you had to know that the actions are retried for 900s when
seeing an error like
> Traceback (most recent call last):
> File "/nix/store/dbvmxk60sv87xsxm7kwzzjm7a4fhgy6y-nixos-test-driver/bin/.nixos-test-driver-wrapped", line 927, in run_tests
> exec(tests, globals())
> File "<string>", line 1, in <module>
> File "<string>", line 31, in <module>
> File "/nix/store/dbvmxk60sv87xsxm7kwzzjm7a4fhgy6y-nixos-test-driver/bin/.nixos-test-driver-wrapped", line 565, in wait_for_file
> retry(check_file)
> File "/nix/store/dbvmxk60sv87xsxm7kwzzjm7a4fhgy6y-nixos-test-driver/bin/.nixos-test-driver-wrapped", line 142, in retry
> raise Exception("action timed out")
> Exception: action timed out
in your (hydra) build failure. Due to the absence of timestamps you were
left guessing if the machine was just slow, someone passed a low timeout
value (which they couldn't until now) or whatever might have happened.
By making this error a bit more descriptive (by including the elapsed
time) these hopefully become more useful.
On my system I have XWayland disabled and therefore only WAYLAND_DISPLAY
is set. This ensures that the graphical output will still be enabled on
such setups (both Wayland and X11 are supported by the viewer).
When performing OCR, some of the Tesseract settings perform better than
others on a variety of different workloads, but they mostly take
~negligible incremental time to run compared to the overhead of running
the ImageMagick filters.
After this commit, we try using all three of the current Tesseract
models (classic, LSTM, and classic+LSTM) to generate output text. This
fixes chromium-90's tests at release-20.09, and should make cases where
you're looking for *specific* text better, with the tradeoff of running
Tesseract multiple times.
To make it sensible to cherrypick this into release-20.09, this doesn't
change the existing API surface for the test driver. In particular,
get_screen_text continues to have the existing behaviour.
According to Python documentation [0], `bufsize=1` is only meaningful in
text mode. As we don't pass in an argument called `universal_newlines`,
`encoding`, `errors` or `text` the file objects aren't opened in text
mode, which means the argument is ignored with a warning in Python 3.8.
line buffering (buffering=1) isn't supported in binary mode,
the default buffer size will be used
This commit removes this warning that appared when using
interactive test driver built with `-A driver`. This is done by
removing `bufsize=1` from Popen calls.
The default parameter when unspecified for `bufsize` is `-1` which
according to the documentation will be interpreted as
`io.DEFAULT_BUFFER_SIZE`. As mentioned by a warning, Python already
uses default buffer size when providing `buffering=1` parameter for
file objects not opened in text mode.
[0]: https://docs.python.org/3/library/subprocess.html#subprocess.Popen
ecb73fd555 introduced a new keepVmState
CLI flag for test-driver.py. This CLI flags gets forwarded to the
Machine class through create_machine.
It created a regression for the boot tests where __main__ end up not
being evaluated. See
https://github.com/NixOS/nixpkgs/pull/97346#issuecomment-690951837 for
bug report.
Defaulting keepVmState to false when __main__ ends up not being
evaluated.
The previous version of the code would only kick in if the state
directory path pointed at a *file*, which never occurs. Making that
codepath actually work reveals an ordering bug, which this patch fixes
as well.
It also replaces the confusing, imperative case log message "delete VM
state directory" with "deleting VM state directory".
Finally, we hint the user about how to prevent this deletion. IE. by
passing the --keep-vm-state flag.
Bug report:
https://github.com/NixOS/nixpkgs/pull/91046#issuecomment-685568750
Credit goes to Edef for the rebase on top of a recent nixpkgs commit
and for writing most of this commit message.
Co-authored-by: edef <edef@edef.eu>
This reverts commit 1bff6fe17c, reversing
changes made to 2995fa48cb.
There’s presumably nothing wrong with this PR, except that it
conflicts with reverting #96254 which broke several tests (#96699).
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
With the Perl driver, machine.sleep(N) was doing a sleep on the guest
machine instead of the host machine. The new Python test driver however
uses time.sleep(), which instead sleeps on the host.
While this shouldn't make a difference most of the time, it *does*
however make a huge difference if the test machine is loaded and you're
sleeping for a minimum duration of eg. an animation.
I stumbled on this while porting most of all my tests to the new Python
test driver and particularily my video game tests failed on a fairly
loaded machine, whereas they don't with the Perl test driver.
Switching the sleep() method to sleep on the guest instead of the host
fixes this.
Signed-off-by: aszlig <aszlig@nix.build>
Keeping the VM state test across several run sometimes lead to subtle
and hard to spot errors in practice. We delete the VM state which
contains (among other things) the qcow volume.
We also introduce a -K (--keep-vm-state) flag making VM state to
persist after the test run. This flag makes test-driver.py to match
its previous behaviour.
xchg is advertised as a bidirectional exchange dir, but file content
transfer from host to VM fails due to caching:
If a file is read in the VM and then modified on the host, subsequent
re-reads in the VM can yield old, cached data.
This is caused by the use of 9p's cache=loose mode that is explicitly
meant for read-only mounts.
9p doesn't provide any suitable cache modes, so fix this by disabling
caching.
Also, remove a now unnecessary sync in the test driver.
These syncs have the goal to transfer host filesystem changes to the VM,
but they have no effect because 1) syncing in the VM can't possibly pull
in host data and 2) 9p is accessing the host filesystem on the cached
layer anyways, so even syncing on the host would have no effect in the
VM.
The test harness provides the commands it wishes to run in Bourne
syntax. This fails if the user uses a different shell. For example,
with fish:
machine.wait_for_unit("graphical-session.target", "alice")
machine # fish: Unsupported use of '='. To run '-u`' with a modified environment, please use 'env XDG_RUNTIME_DIR=/run/user/`id -u`…'
machine # XDG_RUNTIME_DIR=/run/user/`id -u` systemctl --user --no-pager show "graphical-session.target"
machine # ^
machine # [ 16.329957] su[1077]: pam_unix(su:session): session closed for user alice
error: retrieving systemctl info for unit "graphical-session.target" under user "alice" failed with exit code 127
This completes the removal of the nested log feature, which previously
got removed from Nix, Hydra, stdenv and GNU Make. In particular, this
means that the output of VM builds no longer contains a copy of
jQuery.
If a program (e.g. nixos-install) writes more than 1000 lines to
stderr during execute(), then process_serial_output() deadlocks
waiting for the queue to be processed. So use an unbounded queue
instead.
We should probably get rid of the structured log output (log.xml),
since then we don't need the log queue anymore.
