To be squashed

In response to Brett's suggestion that we explicitly try eject
options rather than making assumptions about systemd.  Keeping
this as a separate commit so we can see the options.

cloudinit/distros/__init__.py

@@ -1316,9 +1316,17 @@ def _get_proc_stat_by_index(pid: int, field: int) -> Optional[int]:
 
     @staticmethod
     def eject_media(device: str) -> None:
-        cmd = ["/lib/udev/cdrom_id", "--eject-media", device]
-        if not uses_systemd():
+        cmd = None
+        if subp.which("eject"):
             cmd = ["eject", device]
+        elif subp.which("/lib/udev/cdrom_id"):
+            cmd = ["/lib/udev/cdrom_id", "--eject-media", device]
+        else:
+            raise subp.ProcessExecutionError(
+                cmd="eject_media_cmd",
+                description="eject command not found",
+                reason="neither eject nor /lib/udev/cdrom_id are found",
+            )
         subp.subp(cmd)
 
 def _apply_hostname_transformations_to_url(url: str, transformations: list):