Re: [Qemu-devel] [PATCH 1/2] Bootstrap Python venv for tests

[Cleber Rosa]

On 9/20/18 7:29 PM, Philippe Mathieu-Daudé wrote:
> Hi Cleber,
> 
> On 9/20/18 5:19 PM, 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 requiment, 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.
> 
> Very good idea!
> 
>> Signed-off-by: Cleber Rosa <address@hidden>
>> ---
>>  tests/Makefile.include      | 19 +++++++++++++++++++
>>  tests/venv-requirements.txt |  3 +++
>>  2 files changed, 22 insertions(+)
>>  create mode 100644 tests/venv-requirements.txt
>>
>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>> index 87c81d1dcc..9bb90a83d4 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 " $(MAKE) check-clean          Clean the tests"
>>      @echo
>>      @echo "Please note that HTML reports do not regenerate if the unit 
>> tests"
>> @@ -999,6 +1000,23 @@ check-decodetree:
>>            ./check.sh "$(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=$(BUILD_DIR)/tests/venv-requirements.txt
> 
> $ make check-venv
>   VENV    build/tests/venv
>   PIP     build/tests/venv-requirements.txt
> Could not open requirements file: [Errno 2] No such file or directory:
> 'build/tests/venv-requirements.txt'
> make: *** [tests/Makefile.include:1012: build/tests/venv] Error 1
> 
> This should be:
> 
> TESTS_VENV_REQ=$(SRC_PATH)/tests/venv-requirements.txt
> 

Right, nice catch.

>> +
>> +$(TESTS_VENV_DIR):
>> +    $(call quiet-command, \
>> +            $(PYTHON) -m venv $@, \
>> +            VENV, $@)
>> +    $(call quiet-command, \
>> +            $(TESTS_VENV_DIR)/bin/pip -q install -r $(TESTS_VENV_REQ), \
>> +            PIP, $(TESTS_VENV_REQ))
>> +
>> +check-venv: $(TESTS_VENV_DIR)
> 
> I'm not sure testing the directory creation is enough:
> 

I see your point.  On a previous version, I was looking at specific
Python files ("<module-name>.dist-info") as an extra condition for
successful module installation, but it was too much Python and module
version specific.  Maybe we can add a final command that touches a file
as a flag, say "touch $(TESTS_VENV_DIR)/.install_complete".

> $ make check-venv
>   VENV    build/tests/venv
> The virtual environment was not created successfully because ensurepip
> is not
> available.  On Debian/Ubuntu systems, you need to install the python3-venv
> package using the following command.
> 
>     apt-get install python3-venv
> 
> You may need to use sudo with that command.  After installing the
> python3-venv
> package, recreate your virtual environment.
> 

On Fedora/EL systems, python3 requires both python3-libs (which contains
venv) and python3-pip.  Thanks for testing on Debian/Ubuntu.

Now that questions is whether "tests-venv" should try to do anything
system wide or that requires sudo: I personally don't think it should.

> Failing command: ['build/tests/venv/bin/python3', '-Im', 'ensurepip',
> '--upgrade', '--default-pip']
> 
> make: *** [tests/Makefile.include:1011: build/tests/venv] Error 1
> 
> $ make check-venv
> make: Nothing to be done for 'check-venv'.
> 
> The dir is here but the venv is incomplete.
> 
> 
> Also, once applied your patch 2 which add the avocado dependency,
> running 'check-env' doesn't install the new requirements:
> 
> $ make check-venv
> make: Nothing to be done for 'check-venv'.
> 
> Maybe a make rule checking $(TESTS_VENV_REQ) is enough to trigger an
> install.
> 

That was also a simplification done purpose after the experiments with
the "<module-name>.dist-info" checks I mentioned before.  But, I think
we can fix that by having pip generate a timestamp flag file.  So, if
"venv-requirements.txt" changes, pip will execute again.

Thanks for the suggestions and testing here!
- Cleber.

>> +
>>  # Consolidated targets
>>  
>>  .PHONY: check-qapi-schema check-qtest check-unit check check-clean
>> @@ -1012,6 +1030,7 @@ 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
>>
> 
> Regards,
> 
> Phil.
> 

-- 
Cleber Rosa
[ Sr Software Engineer - Virtualization Team - Red Hat ]
[ Avocado Test Framework - avocado-framework.github.io ]
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