Support for image export

[sipsma]

We only have localdir export at the moment. Image export would also be fairly easy to add support for.

[grouville]

Image export would also be fairly easy to add support for.

@sipsma What is the current dagger equivalent for this Image export primitive ? It it this:

dagger/plan/task/export.go

Lines 88 to 98 in 46b69ac

	// Export image
	resp, err := s.Export(ctx, st, &img, bk.ExportEntry{
	Type: opts.Type,
	Attrs: map[string]string{
	"name": tag.String(),
	},
	Output: func(a map[string]string) (io.WriteCloser, error) {
	file := filepath.Join(dir, opts.Path)
	return os.Create(file)
	},
	}, pctx.Platform.Get())

(To be sure I'm aware of everything)

[sipsma]

@grouville Yep that seems to be where it happens in dagger/dagger. In cloak, we currently have a local dir export here: https://github.com/dagger/cloak/blob/a3aad6f11e994def546a954ccc238877d1e4b56b/core/core.schema.go#L177-L200

Support for image export would probably look quite similar, just with a different exporter type.

However, just FYI we are working on redesigning the core api, which will impact how images are exported: dagger/cloak#163

So it may make sense to wait for that to be settled before adding this feature (unless there's a very immediate need).

[sipsma]

Gonna do this quickly since it is blocking multiple people, not worth waiting for the next API implementation to be merged.

[sipsma]

Implemented here, the upcoming API refactor will also have to port this but don't need this issue open anymore: dagger/cloak@7df6f64