this introduces tar extraction inside a chroot. This is done spawning a
new process. Instead of creating a new executable (difficult to find,
package etc...) it adds the concept of a multicall process (like busybox).
Now a new multicall command "extracttar" is added.
tar.ExtractTar executes this new command passing a pipe to send the
filesMap and the tar contents to stdin.
The incomplete "insecure link" checks are removed from the the tar
functions. Additionally these functions are now not exported and the
extraction directory is always the root directory.
The one provided by appc/spec creates the manifest file with uid=0 and gid=0,
this break tests launched as non root user, because pkg/tar cannot to lchown
the manifest.
Take two at getting the spec vendored into Rocket with Godep.
Since actool is used during the construction of the stage1.aci, it
really needs to be vendored too to prevent any unexpected divergence
between whatever version the user happens to have in their PATH. Thus,
we introduce a silly dummy package (stage1/dummy.go) to coerce Godep
into vendoring actool. This also requires a slight rearrangement of the
appc repo, moving some functionality from actool itself into the aci
package.
Alban Crequy