rofiles-fuse man page
rofiles-fuse — Use FUSE to create a view where directories are writable, files are immutable
rofiles-fuse SRCDIR MNTPOINT
Creating a checkout from an OSTree repository by default uses hard links, which means an in-place mutation to any file corrupts the repository and all checkouts. This can be problematic if one wishes to run arbitrary programs against such a checkout. For example, RPM %post scripts or equivalent.
In the case where one wants to create a tree commit derived from other content, using rofiles-fuse in concert with ostree commit --link-checkout-speedup (or the underlying API) can ensure that only new files are checksummed.
Example: Update an Ostree Commit
# Initialize a checkout and mount $ ostree --repo=repo checkout somebranch branch-checkout $ mkdir mnt $ rofiles-fuse branch-checkout mnt # Now, arbitrary changes to mnt/ are reflected in branch-checkout $ echo somenewcontent > mnt/anewfile $ mkdir mnt/anewdir $ rm mnt/someoriginalcontent -rf # Commit and cleanup $ fusermount -u mnt $ ostree --repo=repo commit --link-checkout-speedup -b somebranch -s 'Commit new content' --tree=dir=branch-checkout $ rm mnt branch-checkout -rf