Re: [PATCH v2 06/22] test: Add exeter+Avocado based build tests

[Stefano Brivio <sbrivio@redhat.com>]

On Mon,  5 Aug 2024 22:36:45 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> Add a new test script to run the equivalent of the tests in build/all
> using exeter and Avocado.  This new version of the tests is more robust
> than the original, since it makes a temporary copy of the source tree so
> will not be affected by concurrent manual builds.

I think this is much more readable than the previous Python attempt.

On the other hand, I guess it's not an ideal candidate for a fair
comparison because this is exactly the kind of stuff where shell
scripting shines: it's a simple test that needs a few basic shell
commands.

On that subject, the shell test is about half the lines of code (just
skipping headers, it's 48 lines instead of 90... and yes, this version
now uses a copy of the source code, but that would be two lines).

In terms of time overhead, dropping delays to make the display capture
nice (a feature that we would anyway lose with exeter plus Avocado, if
I understood correctly):

$ time (make clean; make passt; make clean; make pasta; make clean; make qrap; make clean; make; d=$(mktemp -d); prefix=$d make install; prefix=$d make uninstall; )
[...]
real	0m17.449s
user	0m15.616s
sys	0m2.136s

compared to:

$ time ./run
[...]
real	0m18.217s
user	0m0.010s
sys	0m0.001s

...which I would call essentially no overhead. I didn't try out this
version yet, I suspect it would be somewhere in between.

> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  test/Makefile         |  19 +++++---
>  test/build/.gitignore |   1 +
>  test/build/build.py   | 105 ++++++++++++++++++++++++++++++++++++++++++
>  test/run_avocado      |   2 +-
>  4 files changed, 120 insertions(+), 7 deletions(-)
>  create mode 100644 test/build/build.py
> 
> diff --git a/test/Makefile b/test/Makefile
> index dae25312..d24fce14 100644
> --- a/test/Makefile
> +++ b/test/Makefile
> @@ -64,15 +64,19 @@ LOCAL_ASSETS = mbuto.img mbuto.mem.img podman/bin/podman QEMU_EFI.fd \
>  ASSETS = $(DOWNLOAD_ASSETS) $(LOCAL_ASSETS)
>  
>  EXETER_SH = build/static_checkers.sh
> -EXETER_JOBS = $(EXETER_SH:%.sh=%.json)
> +EXETER_PY = build/build.py
> +EXETER_JOBS = $(EXETER_SH:%.sh=%.json) $(EXETER_PY:%.py=%.json)
>  
>  AVOCADO_JOBS = $(EXETER_JOBS) avocado/static_checkers.json
>  
> -SYSTEM_PYTHON = python3
> +PYTHON = python3
>  VENV = venv
> -PYTHON = $(VENV)/bin/python3
>  PIP = $(VENV)/bin/pip3
> -RUN_AVOCADO = cd .. && test/$(PYTHON) test/run_avocado
> +PYPATH = exeter/py3
> +SPACE = $(subst ,, )
> +PYPATH_TEST = $(subst $(SPACE),:,$(PYPATH))
> +PYPATH_BASE = $(subst $(SPACE),:,$(PYPATH:%=test/%))
> +RUN_AVOCADO = cd .. && PYTHONPATH=$(PYPATH_BASE) test/$(VENV)/bin/python3 test/run_avocado

At least intuitively, I would have no clue what this all does. But it
doesn't matter so much, I could try to find out the day that something
doesn't work.

>  
>  CFLAGS = -Wall -Werror -Wextra -pedantic -std=c99
>  
> @@ -131,13 +135,16 @@ big.bin:
>  	dd if=/dev/urandom bs=1M count=10 of=$@
>  
>  .PHONY: venv
> -venv:
> -	$(SYSTEM_PYTHON) -m venv $(VENV)
> +venv: pull-exeter
> +	$(PYTHON) -m venv $(VENV)
>  	$(PIP) install avocado-framework
>  
>  %.json: %.sh pull-exeter
>  	cd ..; sh test/$< --avocado > test/$@
>  
> +%.json: %.py pull-exeter
> +	cd ..; PYTHONPATH=$(PYPATH_BASE) $(PYTHON) test/$< --avocado > test/$@
> +

Same here.

>  .PHONY: avocado
>  avocado: venv $(AVOCADO_JOBS)
>  	$(RUN_AVOCADO) $(AVOCADO_JOBS)
> diff --git a/test/build/.gitignore b/test/build/.gitignore
> index a6c57f5f..4ef40dd0 100644
> --- a/test/build/.gitignore
> +++ b/test/build/.gitignore
> @@ -1 +1,2 @@
>  *.json
> +build.exeter
> diff --git a/test/build/build.py b/test/build/build.py
> new file mode 100644
> index 00000000..79668672
> --- /dev/null
> +++ b/test/build/build.py
> @@ -0,0 +1,105 @@
> +#! /usr/bin/env python3
> +#
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# PASST - Plug A Simple Socket Transport
> +#  for qemu/UNIX domain socket mode
> +#
> +# PASTA - Pack A Subtle Tap Abstraction
> +#  for network namespace/tap device mode
> +#
> +# test/build/build.sh - Test build and install targets
> +#
> +# Copyright Red Hat
> +# Author: David Gibson <david@gibson.dropbear.id.au>
> +
> +import contextlib
> +import os.path
> +import shutil
> +import subprocess
> +import tempfile
> +
> +import exeter
> +
> +
> +def host_run(*cmd, **kwargs):
> +    return subprocess.run(cmd, check=True, encoding='UTF-8', **kwargs)
> +
> +
> +def host_out(*cmd, **kwargs):
> +    return host_run(*cmd, capture_output=True, **kwargs).stdout

A vague idea only, so far, but I guess it's fine to have some amount of
boilerplate.

> +
> +
> +@contextlib.contextmanager
> +def clone_source_tree():
> +    with tempfile.TemporaryDirectory(ignore_cleanup_errors=False) as tmpdir:
> +        # Make a temporary copy of the sources
> +        srcfiles = host_out('git', 'ls-files').splitlines()
> +        for src in srcfiles:
> +            dst = os.path.join(tmpdir, src)
> +            os.makedirs(os.path.dirname(dst), exist_ok=True)
> +            shutil.copy(src, dst)
> +        os.chdir(tmpdir)
> +        yield tmpdir

This all makes sense.

Of course it would be more readable in shell script (including the trap
to remove the temporary directory on failure/interrupt), but I think
it's as clear as it can get in any other language.

> +
> +
> +def build_target(target, outputs):
> +    with clone_source_tree():
> +        for o in outputs:
> +            assert not os.path.exists(o)
> +        host_run('make', f'{target}', 'CFLAGS="-Werror"')

Compared to:

host	CFLAGS="-Werror" make

I would say it's not great, but again, it makes sense, and it's as good
as it gets, I suppose.

> +        for o in outputs:
> +            assert os.path.exists(o)
> +        host_run('make', 'clean')
> +        for o in outputs:
> +            assert not os.path.exists(o)

Same here,

check	[ -f passt ]
check	[ -h pasta ]
check	[ -f qrap ]

> +
> +
> +@exeter.test
> +def test_make_passt():
> +    build_target('passt', ['passt'])
> +
> +
> +@exeter.test
> +def test_make_pasta():
> +    build_target('pasta', ['pasta'])
> +
> +
> +@exeter.test
> +def test_make_qrap():
> +    build_target('qrap', ['qrap'])
> +
> +
> +@exeter.test
> +def test_make_all():
> +    build_target('all', ['passt', 'pasta', 'qrap'])

These all make sense and look relatively readable (while not as...
writable as shell commands "everybody" is familiar with).

> +
> +@exeter.test
> +def test_make_install_uninstall():
> +    with clone_source_tree():
> +        with tempfile.TemporaryDirectory(ignore_cleanup_errors=False) \
> +             as prefix:
> +            bindir = os.path.join(prefix, 'bin')
> +            mandir = os.path.join(prefix, 'share', 'man')
> +            exes = ['passt', 'pasta', 'qrap']
> +
> +            # Install
> +            host_run('make', 'install', 'CFLAGS="-Werror"', f'prefix={prefix}')
> +
> +            for t in exes:
> +                assert os.path.isfile(os.path.join(bindir, t))
> +                host_run('man', '-M', f'{mandir}', '-W', 'passt')
> +
> +            # Uninstall
> +            host_run('make', 'uninstall', f'prefix={prefix}')
> +
> +            for t in exes:
> +                assert not os.path.exists(os.path.join(bindir, t))
> +                cmd = ['man', '-M', f'{mandir}', '-W', 'passt']

Same, up to here: it's much more readable and obvious to write in shell
script, but I don't find it impossible to grasp in Python, either.

> +                exeter.assert_raises(subprocess.CalledProcessError,
> +                                     host_run, *cmd)

This, I have no idea why. Why is it only in this loop? How does it
affect the control flow?

> +
> +
> +if __name__ == '__main__':
> +    exeter.main()
> diff --git a/test/run_avocado b/test/run_avocado
> index d518b9ec..26a226ce 100755
> --- a/test/run_avocado
> +++ b/test/run_avocado
> @@ -41,7 +41,7 @@ def main():
>          "resolver.references": references,
>          "runner.identifier_format": "{args}",
>      }
> -    suite = TestSuite.from_config(config, name="static_checkers")
> +    suite = TestSuite.from_config(config, name="all")
>      with Job(config, [suite]) as j:
>          return j.run()
>  

Patch 22/22 will take me a bit longer (I'm just looking at these two
for the moment, as you suggested).

-- 
Stefano