Set the propagation a mount asks for - #864
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The reaper that runs at a concurrency of one deletes everything in the test directory except the unpacked rootfs it means to preserve. It held that rootfs path as FileManager reports it, under /var, and compared it against the entries of contentsOfDirectory, which reports them under /private/var, so the preserved path never matched any entry and the rootfs was deleted along with the per-test files. The unpack coordinator still held it as unpacked, so the next test opened a rootfs that was no longer there and failed with a missing file error. Resolve both sides with resolvingSymlinksInPathWithPrivate, which exists for this difference between the two views of the same directory.
Tests guarded for Linux are compiled out on macOS, so `make test` reports success without having run them, and nothing says so. The target that does run them is not mentioned anywhere outside the makefile.
The default kernel the tests fetch had drifted from the one users run. container installs kata 3.28.0 and its 6.18.15 kernel, while these tests fetched 3.17.0, so the suite exercised a guest with a different feature set to the one it is meant to represent. Nested runtimes are the visible case: 3.17.0 was built without nf_tables, so a docker daemon inside a container fails there and works on what ships. Kata moved from xz to zstd between those releases, so the archive is no longer named for its compression and tar is left to recognise it rather than being told, which also holds if the format changes again.
The mount options a runtime spec carries include propagation, which the kernel takes in a mount call of its own rather than alongside the mount it applies to. The call was already here, but nothing set the flags it acts on: option parsing knew every flag except these, so `rshared` and its siblings fell through to the mount data, where the kernel rejects them and the container fails to start. Parse them into their own set, and make the propagation calls from it. A mount can then ask for what runc's spec conversion offers, and the flags a mount is given no longer have to be sifted for propagation bits that never belonged among them.
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Summary
The mount options a runtime spec carries include propagation, which the kernel takes in a mount call of its own rather than alongside the mount it applies to. The call was already here, but nothing set the flags it acts on: option parsing knew every flag except these, so
rsharedand its siblings fell through to the mount data, where the kernel rejects them and the container fails to start.Parse them into their own set, and make the propagation calls from it. A mount can then ask for what runc's spec conversion offers, and the flags a mount is given no longer have to be sifted for propagation bits that never belonged among them.
Dependency and Merge Order
This targets stock
apple/containerization:mainand depends on #863. Please merge #863 first.The head carries #863's three commits as prerequisites, because both PRs target stock
mainand GitHub only allows a fork PR to base on a branch in this repository. Once #863 merges, this branch can take currentmainand its remaining diff is onlySources/ContainerizationOS/Mount/Mount.swiftand the integration test.The dependency is on the test suite work, not the fix: the propagation test needs the kernel #863 selects, since the guest has to be one where the propagation calls behave as the spec describes.
Motivation and Context
The failure is opaque from the outside: a container asking for
rshareddoes not start, and the rejection comes from the kernel refusing an option string it was handed rather than from anything naming propagation. runc's spec conversion offers these flags, so a spec that sets them is well-formed and should work.Testing
swift buildandmake checkclean.swift test: 603 tests in 83 suites passed.container mount propagationasserts the mount is shared by checking that the kernel gave it a peer group, which only a mount told to share carries.Type of Change