Ignition should fail validation if a file conflicts with the parent directory of another file/link/dir

[yasminvalim]

Issue Summary:

Ignition has a bug (tracked in GitHub issue #1457) where it lacks proper validation when a file conflicts with the parent directory of another file, link, or directory. This bug allows users to create configurations that lead to internal inconsistencies. Feel free to verify this in Jira as well.

Expected Behavior:

Ignition should reject configurations that result in internal inconsistencies. Specifically, it should fail validation when files, links, or directories conflict with implicit parent directories.

Actual Behavior:

Currently, users can specify a file that conflicts with the parent directory, leading to potential internal inconsistencies.

Reproduction Steps:

Write a configuration with a file at /foo/bar and a file/directory/link at /foo/bar/baz.
OR
Write a configuration with a file at /foo/bar and a directory at /foo/bar/baz.
OR
Write a configuration with a file at /foo/bar and a link at /foo/bar/baz.

[prestist]

Overall these look like a great start to TTD! looks like there is an understanding of the issue. Just a small pick and make sure to have a positive case that allows a file to be named the same as a parent directory as long as the parent directory is configured.

[yasminvalim]

Overall these look like a great start to TTD! looks like there is an understanding of the issue. Just a small pick and make sure to have a positive case that allows a file to be named the same as a parent directory as long as the parent directory is configured.

Thanks for your review! Good idea, I added positive cases!

[yasminvalim]

Some benchmarking to check performance:

func BenchmarkValidateParents(b *testing.B) {
    cfg := Config{
        Storage: Storage{
            Files: []File{
                {Node: Node{Path: "/foo/bar"}},
            },
            Directories: []Directory{
                {Node: Node{Path: "/foo/bar/baz"}},
            },
        },
    }

    for i := 0; i < b.N; i++ {
        _ = cfg.validateParents(path.New("json"))
    }
}

goos: linux
goarch: amd64
pkg: github.com/coreos/ignition/v2/config/v3_5_experimental/types
cpu: 12th Gen Intel(R) Core(TM) i7-1270P
BenchmarkValidateParents-16      2720104           417.5 ns/op       440 B/op          9 allocs/op
PASS
ok      github.com/coreos/ignition/v2/config/v3_5_experimental/types    1.588s

OTHER EXAMPLE:

[func BenchmarkValidateParents(b *testing.B) {
    cfg := Config{
        Storage: Storage{
            Files: []File{
                {Node: Node{Path: "/foo/bar"}},
            },
            Links: []Link{
                {Node: Node{Path: "/foo/bar/baz"}},
            },
        },
    }

    for i := 0; i < b.N; i++ {
        _ = cfg.validateParents(path.New("json"))
    }
}

goos: linux
goarch: amd64
pkg: github.com/coreos/ignition/v2/config/v3_5_experimental/types
cpu: 12th Gen Intel(R) Core(TM) i7-1270P
BenchmarkValidateParents-16      2664310           429.1 ns/op       440 B/op          9 allocs/op
PASS
ok      github.com/coreos/ignition/v2/config/v3_5_experimental/types    1.604s
](url)

OTHER EXAMPLE

func BenchmarkValidateParents(b *testing.B) {
    cfg := Config{
        Storage: Storage{
            Files: []File{
                {Node: Node{Path: "/foo/bar"}},
                {Node: Node{Path: "/foo/bar/baz"}},
            },
        },
    }

    for i := 0; i < b.N; i++ {
        _ = cfg.validateParents(path.New("json"))
    }
}

goos: linux
goarch: amd64
pkg: github.com/coreos/ignition/v2/config/v3_5_experimental/types
cpu: 12th Gen Intel(R) Core(TM) i7-1270P
BenchmarkValidateParents-16      2810596           423.6 ns/op       440 B/op          9 allocs/op
PASS
ok      github.com/coreos/ignition/v2/config/v3_5_experimental/types    1.630s

[travier]

That looks weird. Why are we validating this with Windows style paths here? This is only about the final system which Linux only AFAIK.

[yasminvalim]

Thanks for pointing that out.
I was having CI failures on Windows, so I created tests to see if my validations applied to Windows as well. They're now working on Windows, but the unit tests should indeed be exclusive to Linux.

[ravanelli]

You shouldn't merge the main branch here. You need to rebase instead

[prestist]

Have you had any luck with building the kola tests locally to see what is going on?