ActiveMQ service improvements

[fkleon]

GitHub Issue: n/a

What does this Pull Request do?

Removes the need for an ubuntu user that is currently required to run ActiveMQ.

Similar background as raised for the old dev environment: islandora-deprecated/claw_vagrant#57

This PR adds a dedicated activemq system user.

What's new?

• Added the activemq system user.
• Added a systemd unit to manage the activemq service, which now runs as the activemq system user.
• Added a transitional task that removes the old init.d symlink

How should this be tested?

• Reprovision ActiceMQ to an existing environments with:
  ansible-playbook -i ./inventory/vagrant/hosts playbook.yml --tags activemq
• Cycle activemq: sudo systemctl restart activemq
• Access the ActiceMQ web UI and make sure it loads correctly: http://localhost:8161/admin/

Interested parties

@Islandora-CLAW/committers

[jonathangreen]

Hi @fkleon. These changes look awesome, much nicer way to deploy ActiveMQ. I will try to give this a test run tomorrow so we can get it merged.

[fkleon]

@jonathangreen Thanks!
I've just noticed that some of these internal ansible roles also have their own repositories, e.g. Islandora-Devops/ansible-role-activemq. I guess you're planning to migrate to those soon?
Which ones are the canonical source for now and should be used for pull requests?

[jonathangreen]

Good call @fkleon, @whikloj is working on breaking out the internal roles and putting them in galaxy in Islandora/documentation#743. I'm thinking we merge this here, and make a note for @whikloj to do a final sync before he does the switchover. @whikloj thoughts?

[jonathangreen]

Tested and looks good to me.

[jonathangreen]

Thanks for the contribution @fkleon!