Re: [Qemu-devel] [PATCH v4 1/3] Bootstrap Python venv for tests

[Philippe Mathieu-Daudé]

On 16/10/2018 15:56, Cleber Rosa wrote:
> On 10/15/18 6:28 PM, Philippe Mathieu-Daudé wrote:
>> Hi Caio,
>>
>> On 15/10/2018 20:41, Caio Carrara wrote:
>>> On 13-10-2018 00:37, Eduardo Habkost wrote:
>>>> On Fri, Oct 12, 2018 at 11:30:39PM +0200, Philippe Mathieu-Daudé wrote:
>>>>> Hi Cleber,
>>>>>
>>>>> On 12/10/2018 18:53, Cleber Rosa wrote:
>>>>>> A number of QEMU tests are written in Python, and may benefit
>>>>>> from an untainted Python venv.
>>>>>>
>>>>>> By using make rules, tests that depend on specific Python libs
>>>>>> can set that rule as a requirement, along with rules that require
>>>>>> the presence or installation of specific libraries.
>>>>>>
>>>>>> The tests/venv-requirements.txt is supposed to contain the
>>>>>> Python requirements that should be added to the venv created
>>>>>> by check-venv.
>>>>>
>>>>> Maybe you (or Eduardo...) what you wrote in the cover:
>>>>>
>>>>>  There's one current caveat: it requires Python 3, as it's based on the
>>>>>  venv module.
>>>>>
>>>>> To explain:
>>>>>
>>>>> $ make check-acceptance
>>>>> /usr/bin/python2: No module named venv
>>>>> make: *** [/home/phil/source/qemu/tests/Makefile.include:1033:] Error 1
>>>>
>>>> Oops, this doesn't look very friendly.
>>>>
>>>> But note that this would become a non-issue if we start requiring
>>>> Python 3 for building QEMU.
>>>>
>>>>
>>>>>
>>>>>>
>>>>>> Signed-off-by: Cleber Rosa <address@hidden>
>>>>>> ---
>>>>>>  tests/Makefile.include      | 20 ++++++++++++++++++++
>>>>>>  tests/venv-requirements.txt |  3 +++
>>>>>>  2 files changed, 23 insertions(+)
>>>>>>  create mode 100644 tests/venv-requirements.txt
>>>>>>
>>>>>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>>>>>> index 5eadfd52f9..b66180efa1 100644
>>>>>> --- a/tests/Makefile.include
>>>>>> +++ b/tests/Makefile.include
>>>>>> @@ -12,6 +12,7 @@ check-help:
>>>>>>          @echo " $(MAKE) check-block          Run block tests"
>>>>>>          @echo " $(MAKE) check-tcg            Run TCG tests"
>>>>>>          @echo " $(MAKE) check-report.html    Generates an HTML test 
>>>>>> report"
>>>>>> +        @echo " $(MAKE) check-venv           Creates a Python venv for 
>>>>>> tests"
>>>>>>          @echo " $(MAKE) check-clean          Clean the tests"
>>>>>>          @echo
>>>>>>          @echo "Please note that HTML reports do not regenerate if the 
>>>>>> unit tests"
>>>>>> @@ -1017,6 +1018,24 @@ check-decodetree:
>>>>>>            ./check.sh "$(PYTHON)" "$(SRC_PATH)/scripts/decodetree.py", \
>>>>>>            TEST, decodetree.py)
>>>>>>  
>>>>>> +# Python venv for running tests
>>>>>> +
>>>>>> +.PHONY: check-venv
>>>>>> +
>>>>>> +TESTS_VENV_DIR=$(BUILD_DIR)/tests/venv
>>>>>> +TESTS_VENV_REQ=$(SRC_PATH)/tests/venv-requirements.txt
>>>>>> +
>>>>>> +$(TESTS_VENV_DIR): $(TESTS_VENV_REQ)
>>>>>> +        $(call quiet-command, \
>>>>>> +            $(PYTHON) -m venv --system-site-packages $@, \
>>>>>> +            VENV, $@)
>>>>>> +        $(call quiet-command, \
>>>>>> +            $(TESTS_VENV_DIR)/bin/python -m pip -q install -r 
>>>>>> $(TESTS_VENV_REQ), \
>>>>>> +            PIP, $(TESTS_VENV_REQ))
>>>>>> +        $(call quiet-command, touch $@)
>>>>>
>>>>> Hmm maybe we should print something like:
>>>>>
>>>>>   "You can now activate this virtual environment using:
>>>>>     source $(TESTS_VENV_DIR)/tests/venv/bin/activate"
>>>>
>>>> I'm not sure this would be necessary: I expect usage of the venv
>>>> to be completely transparent.
>>>>
>>>> If we require people to learn what venv is and manually activate
>>>> it, I'd say we have failed to provide usable tools for running
>>>> the tests.
>>>>
>>>
>>> Actually this is not necessary since the avocado is being called from
>>> the "venv python binary" as you can see in the check-acceptance target.
>>>
>>> This way all the requirements installed in the test venv can be used
>>> without activating the virtual environment.
>>
>> Well this is only true if you call 'make check-acceptance', not if you
>> want to filter tests, or run the single file you are working on...
>> Or am I missing something? The only option user-configurable (without
>> activating the venv) is the output of all tests via the AVOCADO_SHOW env
>> var.
> 
> Allowing someone to just run `make check-acceptance` is the primary and
> most important goal here IMO.  It's supposed to be simple, which means,
> not having too many knobs.
> 
>>
>> This might be enough for a maintainer checking his subsystem, but I
>> don't find this practical for a acceptance test writer. And we want for
>> people to contribute adding tests, right?
>> Well, if we have maintainer running them, this is already a win :)
>>
> 
> Today, with the code AS-IS, you can still do:
> 
>  $ tests/venv/bin/avocado run [all your options] tests/acceptance

If this is documented, we don't need the other tricks and your series is
fine as it!

> 
> I think the subsystem and maintainers question will come, but it's a
> different discussion.  Contradicting myself now and getting into that
> discussion, :P, it could be as simple as `make TAG=foo check-acceptance`
> that gets passed to Avocado.  Or, in line with other check targets,
> `make check-acceptance-foo`.
> 
> - Cleber.
> 
>>>
>>>>
>>>>>
>>>>>> +
>>>>>> +check-venv: $(TESTS_VENV_DIR)
>>>>>> +
>>>>>>  # Consolidated targets
>>>>>>  
>>>>>>  .PHONY: check-qapi-schema check-qtest check-unit check check-clean
>>>>>> @@ -1030,6 +1049,7 @@ check-clean:
>>>>>>          rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
>>>>>>          rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), 
>>>>>> $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
>>>>>>          rm -f tests/test-qapi-gen-timestamp
>>>>>> +        rm -rf $(TESTS_VENV_DIR)
>>>>>>  
>>>>>>  clean: check-clean
>>>>>>  
>>>>>> diff --git a/tests/venv-requirements.txt b/tests/venv-requirements.txt
>>>>>> new file mode 100644
>>>>>> index 0000000000..d39f9d1576
>>>>>> --- /dev/null
>>>>>> +++ b/tests/venv-requirements.txt
>>>>>> @@ -0,0 +1,3 @@
>>>>>> +# Add Python module requirements, one per line, to be installed
>>>>>> +# in the tests/venv Python virtual environment. For more info,
>>>>>> +# refer to: https://pip.pypa.io/en/stable/user_guide/#id1
>>>>>>
>>>>>
>>>>> Tested-by: Philippe Mathieu-Daudé <address@hidden>
>>>>
>>>
>>>
>