During a snapshot, when a file changed and not its parent directories,
the parent directories weren't added to the layer. This is inconsistent
with Docker's behavior which always add parent directories to the layer.
In some edge-cases, it could lead to problems with docker considering
that parent directories where owned by root in forthcoming layers
although they shouldn't (see #1163).
Also, Docker seems to be POSIX compliant regarding the name of
directories in the archive, which always have a slash appended. This
commit also fixes this.
Fixes#1163
When using cache, the rootfs may not have been extracted. This prevents uname/gname from resolving
as there is no /etc/password or /etc/group. This makes this layer unnecessarily differ from
a cached layer which does contain this information. Omitting these should be consistent with Docker's
behavior.
filesToAdd is sorted in TakeSnapshotFS, but not here. This makes ordering unpredictable within the layer's tarball,
causing the SHA to differ even if layer contents haven't changed
When a Dockerfile command requires using the TakeSnapshotFS function,
the resulting layer has a random ordering of files. This causes the
layer to have a non-deterministic hash defeating the reproducible flag.
Issue #710 appears to document this issue as well.
To fix, always sort the list of files to be added in scanFullFilesystem.
This avoids trying to sort the file list during execution, and takes
almost no time to complete.
* Add parent directories of adding files
* Add integration Dockerfile to test parent directory permissions
* Remove unnecessary helper method
* Use a file on the internet for integration Dockerfile
Tejal Desai