Add Docker Swarm config file, and Swarm & compose config file support

[SvenDowideit]

for #1362

see README.md changes for how&what it does

can be tested using the image at svendowideit/docker-gitlab

[r2evans]

Does this mean "If you're not using one of these files, then don't include its entry in the docker-compose file"? It's a little confusing as currently worded.

[SvenDowideit]

what do you think @solidnerd ?

[solidnerd]

Hey @SvenDowideit,

thanks for your work. I think it is a nice cool idea to support that.

I would like to see this as an additional content so for this case I would like to have it as feature. That means I think we should also need to set an environment variable that allows us to use this feature something like SUPPORT_DOCKER_SWARM_CONFIGS. Also I don't like the change in the standard docker-compose.yml because this a breaking change for the project because compose in version 2 is for single hosts and everything higher than 3.x is for the cluster approach. Also this feature could be used by kubernetes configmaps. I think it would be nice for the user to have an example with that. So i think we could gonna put this in contrib/docker-swarm. In future there will be also support for helm and pure k8s.

WDYT ?

[SvenDowideit]

@solidnerd idk - SUPPORT_DOCKER_SWARM_CONFIGS seems redundant - if you're not using Docker Swarm secrets, then there are no swarm files - so the new code in runtime/functions won't trigger.

wrt moving the contrib - can do...

[solidnerd]

I think we will support this for 10.8.0 and yes you have right an extra env will make this redundant .

I tested it and it's working for me. Thanks for the work ;)

[SvenDowideit]

@solidnerd awesome! looking forward to it :)