[Libguestfs] [PATCH nbdkit] s3: Only run the tests if boto3 is installed

[Richard W.M. Jones]

On Tue, May 17, 2022 at 11:53:44AM +0200, Laszlo Ersek wrote:
> On 05/17/22 10:55, Richard W.M. Jones wrote:
> > ERROR: S3 (unittest.loader._FailedTest)
> > ----------------------------------------------------------------------
> > ImportError: Failed to import test module: S3
> > Traceback (most recent call last):
> >   File "/usr/lib64/python3.10/unittest/loader.py", line 154, in loadTestsFromName
> >     module = __import__(module_name)
> >   File "/home/rjones/d/nbdkit/plugins/S3/S3.py", line 41, in <module>
> >     import boto3
> > ModuleNotFoundError: No module named 'boto3'
> > 
> > Reported-by: Laszlo Ersek
> > Fixes: commit 5130c43bc1f9
> > ---
> >  tests/test-S3-unit.sh | 1 +
> >  tests/test-S3.sh      | 1 +
> >  2 files changed, 2 insertions(+)
> > 
> > diff --git a/tests/test-S3-unit.sh b/tests/test-S3-unit.sh
> > index 6b6adf02..8a32dd4c 100755
> > --- a/tests/test-S3-unit.sh
> > +++ b/tests/test-S3-unit.sh
> > @@ -37,6 +37,7 @@ set -x
> >  
> >  requires $PYTHON --version
> >  requires $PYTHON -c 'import unittest'
> > +requires $PYTHON -c 'import boto3'
> >  
> >  # Python has proven very difficult to valgrind, therefore it is disabled.
> >  if [ "$NBDKIT_VALGRIND" = "1" ]; then
> > diff --git a/tests/test-S3.sh b/tests/test-S3.sh
> > index de94751e..e51ef2ac 100755
> > --- a/tests/test-S3.sh
> > +++ b/tests/test-S3.sh
> > @@ -36,6 +36,7 @@ set -x
> >  
> >  requires hexdump --version
> >  requires $PYTHON --version
> > +requires $PYTHON -c 'import boto3'
> >  requires nbdcopy --version
> >  requires_plugin python
> >  
> > 
> 
> This was my very first idea too, but does it not conflict with having a
> fake boto3 module too, at "tests/test-S3/boto3"?

Yeah I guess the real problem is that the mocked boto3 isn't working
for some reason.  FWIW this works (with mocked boto3) in nbdkit 1.30.

> In particular, "tests/test-S3.sh" already contains:
> 
>   # There is a fake boto3 module in test-S3/ which we use as a test
>   # harness for the plugin.
>   requires test -d test-S3
>   export PYTHONPATH=$srcdir/test-S3:$PYTHONPATH
> 
> In other words, if you added the new line
> 
>   requires $PYTHON -c 'import boto3'
> 
> to the same file, but under the PYTHONPATH extension, then I *think* the
> new "requires" would succeed, but the test case would fail the same way
> -- because the fake module does not expose the new exception type.
> 
> Of course I'm also 100% fine if we make both test cases dependent on the
> *real* boto3 module, but should we then eliminate the "test-S3"
> directory? (The fake module, that is?)

So I think we shouldn't ever be using the real boto3 module, because
that might mean we try to connect to an S3 instance.

Let's ditch this patch and I'll have another look.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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