Is there official Docker image of Oracle XE database?
there is no official docker image available but you can refer following git repo to make it
https://github.com/freneticdisc/oracle-blog-examples/tree/master/Docker%20-%20Oracle%20Database
or
https://github.com/wnameless/docker-oracle-xe-11g
This seems to be Oracle's official repository for docker - https://github.com/oracle/docker-images More details here - https://blogs.oracle.com/oraclemagazine/deliver-oracle-database-18c-express-edition-in-containers