container/store: Process whiteouts #359
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This is just cleaner. Or it WOULD be if there wasn't a bug in `OstreeRepoFile` we need to work around.
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Draft since this passes unit test CI, but I want to test it out for real on a host system and more carefully check that e.g. we're not doing anything stupid like physical file copies during the checkout/commit phase. |
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OK yep, been playing with this some more and it looks like it's working quite well! |
lucab
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Aug 26, 2022
A long time ago, in a galaxy far far away, a few of us in the ostree space did some initial work on Docker-related things; specifically support for whiteouts landed in ostreedev/ostree@baaf745 I wish at that time we'd realized how we could more natively support fetching containers; but, it never occurred to me to fork off skopeo to do all the heavy lifting for the *fetch* side, which would have been a lot of work to reimplement particularly in C. Oh well, better late than never! Anyways, that whiteout processing was only designed to happen at checkout time - i.e. when materializing the final filesystem tree. I think this was actually a misdesign and we should add `ostree_mutable_tree_write_with_whiteouts` so that the whiteouts are processed in-memory. However for now, there's a relatively low cost to temporarily materializing the merged tree via hardlinks and handle whiteouts via the existing code, so let's do that. Closes: ostreedev#273
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Also dropped the manual |
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A long time ago, in a galaxy far far away, a few of us in the
ostree space did some initial work on Docker-related things; specifically
support for whiteouts landed in
ostreedev/ostree@baaf745
I wish at that time we'd realized how we could more natively
support fetching containers; but, it never occurred to me to fork
off skopeo to do all the heavy lifting for the fetch side, which
would have been a lot of work to reimplement particularly in C.
Oh well, better late than never!
Anyways, that whiteout processing was only designed to happen at
checkout time - i.e. when materializing the final filesystem tree. I
think this was actually a misdesign and we should add
ostree_mutable_tree_write_with_whiteoutsso that the whiteoutsare processed in-memory.
However for now, there's a relatively low cost to temporarily
materializing the merged tree via hardlinks and handle whiteouts
via the existing code, so let's do that.
Closes: #273