Description of problem:

The oci-systemd-hook tries to propagate the journal from systemd-based container to the host by creating and mounting host's directory to the container.

However, when /var/log is not available in the container image, oci-systemd-hook mounts under /run/journal instead of under /run/log/journal. And systemd-journald(8) says:

       The journal service stores log data either persistently below
       /var/log/journal or in a volatile way below /run/log/journal/ (in the
       latter case it is lost at reboot).

So the directory on the host is created and mounted but not used by systemd in the container.

Version-Release number of selected component (if applicable):

oci-systemd-hook-0.1.17-3.gitbd86a79.fc28.x86_64

How reproducible:

Deterministic.

Steps to Reproduce:
1. Have Dockerfile

FROM registry.fedoraproject.org/fedora:28
RUN mkdir -p /data-template/var && mv /var/log /data-template/var/log && ln -s /data/var/log /var/log
VOLUME [ "/data" ]
ENTRYPOINT [ "/usr/sbin/init" ]

2. Build image: docker build -t journald .
3. Run container: docker run --name systemd --rm -i journald
4. In different terminal, check the mounted directory:
   $ docker exec systemd mount | grep journal
/dev/mapper/vg_host-lv_fedora on /run/journal/92bfd207a8dc5f5e097172aa5adff47c type ext4 (rw,relatime,seclabel)
5. Check where the journal is actually stored in the container:
   $ docker exec systemd ls -dla /run/journal/92bfd207a8dc5f5e097172aa5adff47c/system.journal /run/log/journal/92bfd207a8dc5f5e097172aa5adff47c/system.journal
6. Check if the journal is stored on host:
   $ ls -la /var/log/journal/92bfd207a8dc5f5e097172aa5adff47c/

Actual results:

The ls in the container:

-rw-r-----+ 1 root systemd-journal 839680 Sep 12 15:31 /run/log/journal/92bfd207a8dc5f5e097172aa5adff47c/system.journal
ls: cannot access '/run/journal/92bfd207a8dc5f5e097172aa5adff47c/system.journal': No such file or directory

The ls on the host:

total 80
drwxr-sr-x+    2 root root             4096 Sep 12 17:31 .
drwxr-sr-x+ 1119 root systemd-journal 65536 Sep 12 17:31 ..

Expected results:

The ls in the container:

-rw-r-----+ 1 root systemd-journal 839680 Sep 12 15:31 /run/log/journal/92bfd207a8dc5f5e097172aa5adff47c/system.journal
ls: cannot access '/run/journal/92bfd207a8dc5f5e097172aa5adff47c/system.journal': No such file or directory

The ls on the host:

total 80
drwxr-sr-x+    2 root root             4096 Sep 12 17:31 .
drwxr-sr-x+ 1119 root systemd-journal 65536 Sep 12 17:31 ..
-rw-r-----+    1 root systemd-journal 839680 Sep 12 15:31 system.journal

Additional info: