Run ActiveMQ container as a non-root user

[pradeep85841]

Summary

This PR modifies the Dockerfile to run the ActiveMQ container
as a dedicated non-root user, improving security and following
Docker best practices.

Changes

• Added 'activemq' user and group
• Ensured all ActiveMQ directories are owned by this user
• Dropped root privileges before starting the broker
• Adjusted permissions of entrypoint script

Testing

• Verified container starts successfully
• Verified ActiveMQ process runs as 'activemq' user:

  docker exec -it <container> ps -ef | grep java
  docker exec -it <container> whoami
  docker exec -it <container_name_or_id> ls -l /usr/local/bin/entrypoint.sh

[jbonofre]

FYI a similar PR has been created a few months ago. I will take a look on this one.

[jeanouii]

The test has been merged already as part of the other PR. So you probably want to rebase this one.
I probably would have created an issue in JIRA and close the other PR, because they are both targeting the same file essentially improving Docker capabilities. They rely anyways on each other.

What do you think?

[pradeep85841]

Thanks, that’s helpful. I’ll rebase this PR on top of the merged changes so it aligns with the current Docker improvements. Let me know if you’d prefer a different approach.

[jbonofre]

@pradeep85841 I gonna review the PR tomorrow. Thanks !

[jbonofre]

FYI, here's the corresponding Jira: https://issues.apache.org/jira/browse/AMQ-9588

[jbonofre]

This is unrelated to the Docker image.

Can you please remove this file from the PR ?

[jeanouii]

The PR should have been rebased but it won't matter to much here because the test was part of another PR that got merged last week #1631
I think we are good to go.

[jbonofre]

Superseded by #1665