Problem when trying to attach local binary resource

[marceloneppel]

Hi Juju team!
I’m using this lib through pytest-operator in my charm integration tests where I add one .tar.gz as a resource in the deployment.

What happens is that I couldn’t find a way to attach the resource using the attach_resource method. I’m getting an error when I try to pass the resource as a binary content to that method:

resources = {"patroni": "patroni.tar.gz"}
app = await ops_test.model.deploy(
    charm, resources=resources, application_name=application_name, series=series
)
with open("patroni.tar.gz", 'rb') as f:
    app.attach_resource('patroni', "patroni.tar.gz", f)

Traceback (most recent call last):
  File "/home/neppel/Canonical/postgresql-operator/tests/integration/test_charm.py", line 60, in test_deploy
    app.attach_resource('patroni', "patroni.tar.gz", f)
  File "/home/neppel/Canonical/postgresql-operator/.tox/integration/lib/python3.8/site-packages/juju/application.py", line 454, in attach_resource
    headers['Content-Sha384'] = hashlib.sha384(bytes(data, 'utf-8')).hexdigest()
TypeError: encoding without a string argument

I could attach the resource only when using the juju function:

await ops_test.juju("attach-resource", "postgresql-focal", "patroni=patroni.tar.gz")

Am I doing something wrong when using attach_resource from the lib?

Some more details:

• It's a machine charm.
• I'm testing locally with a local charm (not present in charmhub).
• The test works if I use a plain text file instead of a binary file (it looks like that the lib code is trying to convert the content to bytes to generate a sha checksum, which breaks because the content is already as bytes).