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

[Caio Carrara <ccarrara@redhat.com>]

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 <crosa@redhat.com>
>>> ---
>>>  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.

> 
>>
>>> +
>>> +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 <philmd@redhat.com>
> 


-- 
Caio Carrara
Software Engineer, Virt Team
Red Hat
ccarrara@redhat.com