[xwiki-users] skins, configuration, properties and symlinks

Hello, I am trying to create a docker container (based on tomcat:jre8) for xwiki which keeps configuration and skins in volumes. So far, I have made enough progress that the xwiki is being deployes and the configuration is accepted. My skins, however, are not. I am using /var/local/xwiki/ as environment.PermanentDirectory and I have 3 extras stored in there - xwiki.cfg, xwiki.properties and a customSkin-directory. I already tried to create symlinks in the container, pointing to the files at the mount point, this was not working as the properties file was simply ignored and the symlink was not followed. I understood this concerning the properties file, I do not quite understand why the cfg seems to be ignored as well (since several template files were not loaded at all). So I had a workaround for this. My problem is, that the symlink to the custom skin directory is present, working, and it SHOULD work, but whenever I add ?skin=mySkin to the current page URL (and the folder is named mySkin), my browser displays the flamingo skin. Is there another place, or another way, to keep the skins persisted, in a volume to be mounted on docker? Thanks in advance