nydusify supports localfs filesystem backend

[mhotan]

Relevant Issue (if applicable)

N/A

Details

Support localfs for nydusify commands. Specifically useful for convert for local filesystem-backed backend. The inspiration for this change was to test running Nydus with GCSFuse backend localfs on GKE. This is effectively a workaround as Nydus support for GCP Artifact Registry (#1594) is still a work in progress.

Types of changes

What types of changes does your PullRequest introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

Go over all the following points, and put an x in all the boxes that apply.

• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.67%. Comparing base (da2510b) to head (3fc325c).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1637      +/-   ##
==========================================
- Coverage   60.70%   60.67%   -0.04%     
==========================================
  Files         146      146              
  Lines       48355    48355              
  Branches    46322    46322              
==========================================
- Hits        29355    29339      -16     
- Misses      17232    17247      +15     
- Partials     1768     1769       +1     

Files with missing lines	Coverage Δ
contrib/nydusify/cmd/nydusify.go	13.40% <100.00%> (ø)

... and 3 files with indirect coverage changes

[imeoer]

LGTM, thanks! Do you need to use nydus snapshotter and make corresponding changes?

[mhotan]

LGTM, thanks! Do you need to use nydus snapshotter and make corresponding changes?

Yes, I am using/installing Nydus snapshotter in our own GCP cluster but I am currently unaware of what corresponding changes you are referring to.

In our own fork and branch of nydus-snapshotter we been patching snapshotter.sh boot script to fix containerd config updating logic. The currently logic was not working within our GKE provisioned containerd config.toml.