From the PR that implemented empty_dirs, it seems there's support for defining dir owners (with the names argument) and mode into the add_empty_dir method of TarFile class.
But the container_image rule (and container_layer) supports only mode.
This works:
container_image(
name = "with_empty_dirs",
empty_dirs = [
"etc",
"foo",
"bar",
],
mode = "0o777",
)
But this returns an error: "ERROR: (...) no such attribute 'names' in 'containerimage' rule":
container_image(
name = "with_empty_dirs",
empty_dirs = [
"etc",
"foo",
"bar",
],
names = "nginx",
)
Do we need to “write a customized container_image” if we want to add support for owner of empty_dirs?
In a BUILD file, the attribute you're looking for is ownername. See the pkg_tar reference documentation documentation for more details. Also, I don't think you can pass it directly to container_image, you have to create a separate pkg_tar first. Like this:
pkg_tar(
name = "with_empty_dirs_tar",
empty_dirs = [
"etc",
"foo",
"bar",
],
ownername = "nginx.nginx",
)
container_image(
name = "with_empty_dirs",
tars = [":with_empty_dirs_tar"],
)
In general, container_image has a subset of pkg_tar as direct attributes to make simple forms of adding files, but for complex use cases you should create a pkg_tar yourself for full access to all of its features for adding/arranging files and setting their ownership.
The names you see in that PR is a variable in a Python helper tool which the BUILD file rules use as part of the implementation. There's a layer of abstraction between what you write in a BUILD file and that Python code.