pin: new package for loading bpf pins and walking bpffs directories

[ti-mo]

See individual commits.

The API added in this PR:

type Pinner interface {
	Pin(string) error
}

// Load retrieves a pinned object from a bpf virtual filesystem. It returns one
// of [ebpf.Map], [ebpf.Program], or [link.Link].
//
// Trying to open anything other than a bpf object is an error.
func Load(path string, opts *ebpf.LoadPinOptions) (Pinner, error)

// WalkDirFunc is the type of the function called for each object visited by
// [WalkDir]. It's identical to [fs.WalkDirFunc], but with an extra [Pinner]
// argument. If the visited node is a directory, obj is nil.
//
// err contains any errors encountered during bpffs traversal or object loading.
type WalkDirFunc func(path string, d fs.DirEntry, obj Pinner, err error) error

// WalkDir walks the file tree rooted at path, calling bpffn for each node in
// the tree, including directories. Running WalkDir on a non-bpf filesystem is
// an error. Otherwise identical in behavior to [fs.WalkDir].
//
// See the [WalkDirFunc] for more information.
func WalkDir(root string, bpffn WalkDirFunc) error

[mtardy]

I love this!

[rgo3]

:very_nice:

[dylandreimerink]

Looking good to me 🚀

[mtardy]

This is so much better, look at the improvement cilium/tetragon@ef53ab5. It removed sketchy code. Thanks again!

[ti-mo]

This is so much better, look at the improvement cilium/tetragon@ef53ab5. It removed sketchy code. Thanks again!

Thanks for the feedback, enjoy!