Search before asking
Version
In the GitHub repository for branch-3.0, and master the directory is build/docker is obsolete.
Minimal reproduce step
I looked for uses of the Dockerfile and https://hub.docker.com/r/apachepulsar/pulsar-build - the image is 9 months old.
What did you expect to see?
Either the README states this is obsolete, or the directory is removed.
What did you see instead?
The README refers to ubuntu:16.04 and this is old stuff that is not used, If you want to create a similar images then build/build_java_test_image.sh which uses Maven.
Anything else?
No response
Are you willing to submit a PR?