It looks like runc passes a sub-set of its state to the hooks it runs. This is at odds with the OCI specification which states that:

The state of the container is passed to the hooks over stdin, so the hooks could get the information they need to do their work.

The OCI spec also states:

The state of a container MUST include, at least, the following properties:

• ociVersion
• id
• status
• pid
• bundlePath
• annotations

Crucially, also runc passes a root element when it should be passing bundlePath. Further, https://github.com/projectatomic/oci-systemd-hook has a bug where it is relying on root even though it should be bundlePath:

• https://github.com/projectatomic/oci-systemd-hook/blob/master/src/systemdhook.c

See intel/cc-oci-runtime#270 for further details.