Description

When the driver gets the same CreateVolume request more than once, it should return the exact same response each time. Unfortunately, it does not return the same Volume in the CreateVolume Response when using NFS.

The first time a driver creates a NFS volume, it will return a CSI volume with the available capacity of that volume: total size - reserved size for overhead (1.5 Gb)
When the driver receives a CreateVolume request for a NFS volume that already exists, the driver will return a CSI volume with the total size of the volume, not accounting for the 1.5 Gb of overhead. This can lead to a few issues, so this PR is:

1. Fixing the issue with idempotent CreateVolume NFS calls
2. Adds more logging to the driver to make debugging easier
3. Overhauling the csi-sanity scripts to make running/configuring the tests easier
4. Several small tweaks to pass more csi-sanity tests; these changes are:

• CreateVolume will now check SC params to determine if NFS should be used, since sanity test seems to expect the params to be enough to tell the driver which fstype to use
• CreateVolume will check requisite topology after checking Preferred topology, since sanity test only adds requisite topology to CreateVolume request, not preferred topology (see here)
• When source snapshot/volume cannot be found, CreateVolume will return a NotFound error code
• When NodePublish can't find the nodeID, it will return a NotFound error code
• During NodeUnpublish, the targetPath is now removed after unmount
• During NodeExpandVolume, if volume is not found, it will return a NotFound error code
• In NodeExpandVolume, moved the targetPath param check before the NFS check, to ensure the func is csi spec compliant in cases where NFS is used

GitHub Issues

List the GitHub issues impacted by this PR:

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• Backward compatibility is not broken

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

• Tested out creating and deleting a NFS volume 1000x, verified that in the idempotent cases, the size was still set correctly, results tracked internally
• Added and ran UT
• Ran cert-csi certify with NFS storage class, results tracked internally
• csi-sanity tests were run with NFS, results tracked internally
• csi-sanity tests were run with ext4, results tracked internally

Ran 68 of 92 Specs in 706.781 seconds
SUCCESS! -- 68 Passed | 0 Failed | 1 Pending | 23 Skipped