oras installed from snap cannot access config file and credential store/helpers

[qweeah]

What happened in your environment?

As is discussed in #1079, oras CLI installed from snap will be run in a snap sandbox, which have limited access to docker config file in the home directory and other cred store/helper binaries.

What did you expect to happen?

oras on snap should disable strict confinement and user should use classic snap install to avoid above limitation.

How can we reproduce it?

See #1079

What is the version of your ORAS CLI?

1.0.0 installed from snap

What is your OS environment?

20.04

Are you willing to submit PRs to fix it?

• Yes, I am willing to fix it.

[qweeah]

I have automated the build and publishing process in my own fork but found that the publishing is rejected by Snapcraft because the classic confinement is not granted by default. Following their instructions, I raise a discussion in the forum to ask to an exception, see https://forum.snapcraft.io/t/request-for-classic-confinement-oras-and-oras-test/36826

[qweeah]

Closing this issue as the classic confinement request is already approved