Plugin @id or path for <storage> required when 'persistent' is true about fluent-plugin-systemd

[Globegitter]

@errm I was just confused because of the error message saying @id or path so I expected I was able to set @id but @cosmo0920 gave the answer it seems - thanks :)

[errm]

If you set persistent true it is required to give a path to the file used to store the cursor...

A working example is given in the README, could you explain what you expect to happen with this configuration? since it just looks invalid to me.

[cosmo0920]

How about the following configurations?
Because storage plugin does not handle file path with @id.
Instead we can specify it storage directive's attributes.

    <source>
      @type systemd
      filters [{ "_SYSTEMD_UNIT": "kubelet.service" }]
      pos_file /var/log/gcp-journald-kubelet.pos
      read_from_head true
      tag kubelet
      @id in-systemd-kubelet
      <storage in-systemd-kubelet-storage>
        @type local
        persistent true
      </storage>
    </source>