Add support for enterprise edition

[ErwinJunge]

I've rebased the commits from #1477 onto current master and updated to the current structure of upstream gitlab. Credits for original idea go to original author of #1477 (@grimmy)

[ErwinJunge]

I've rebased on top of master, since the fixes in there are required for a working deploy.

[tiredofit]

There is still alot of work required to get a full EE working - While this may provide access to some of the EE features like multiple issue boards etc - There are timers and configuration settings that need to be added into the gitlab.yml, and also the inclusion of the Gitlab Elasticsearch Indexer. Just as an FYI!

[ErwinJunge]

@tiredofit Thanks for the tip! Can you perhaps point me in the direction of somewhere that I can find out what timers and configuration settings you're talking about? I'd love to add them, since we're actually using this build.

Note to self: Gitlab Elasticsearch Indexer docs are here: https://docs.gitlab.com/ee/integration/elasticsearch.html

[tiredofit]

Lines 316-415: https://github.com/tiredofit/docker-gitlab-ee/blob/master/install/assets/gitlab/config/gitlabhq/gitlab.yml
I learned this from reading https://docs.gitlab.com/ee/install/installation.html and as well this repository.

[adamlc]

I'd be interested to see where this goes as we're considering moving to EE!

Looks like officially its now recommended to install using kubernetes.