message: only create if not existing
diff: @@ -23,7 +23,7 @@ ENV TMPDIR=/tmp \
  # we need root for the fix-permissions to work
  USER root
  -RUN mkdir /var/solr
  +RUN mkdir -p /var/solr
  RUN fix-permissions /var/solr \
  && fix-permissions /opt/solr/server/logs \
  && fix-permissions /opt/solr/server/solr
  