For those of you like me who want to explicitly set the variable without relying on which of the two Docker images with the same tag you’re pulling down, and you’re using a Dockerfile to add on to make your own Solr Docker image, add these lines:
# Add option to mitigate log4j security vulnerability. USER root RUN echo 'SOLR_OPTS="$SOLR_OPTS -Dlog4j2.formatMsgNoLookups=true"' >> /etc/default/solr.in.sh USER solr Andy
