Panic: Concurrent Map Writes

[cvgw]

Expected behavior

container-diff diff does not panic due to concurrent map writes

Actual behavior

container-diff/cmd/diff.go

Line 118 in bca8ca4

image1 = processImage(image1Arg, errChan)

Will cause a panic due to concurrent map writes

This is because processImage is called in two goroutines.
processImage eventually calls util.unpackTar which has unsynchronized access to util.hardlinks

container-diff/pkg/util/tar_utils.go

Line 137 in bca8ca4

hardlinks[target] = linkname

Information

• container-diff version: I'm trying to figure this out (it's the kaniko kokoro build)
• Operating system: I'm trying to figure this out (it's the kaniko kokoro build)

Steps to reproduce the behavior

1. I haven't seen this error locally; only in the kaniko kokoro build

[nkubala]

@cvgw thanks for the issue. our team doesn't really have the engineering bandwidth to fix this issue right now, but contributions are certainly welcome. this should be fixable by using a SyncMap