Add information about beach-head services

[mestadler]

Initial PR for the servicetemplate usage guide.

[DinaBelova]

@mestadler can you please

1. share what's the status of this PR? Afair this was not in final stage yet, we discussed it with you and @wahabmk - are there any changes since that time? I do not see them in the commits, so maybe it was not yet updates, correct?
2. as a suggestion - can you also please extend quick start guide section in a form of separate commit in PR? Will be nice to have section w/ kyverno or nginx installation in quickstart

[wahabmk]

I re-organized some of the information already existing in this PR + more info into the following:

1. deploy-services-managedcluster.md: Shows how beach-head services can be deployed with a ManagedCluster object.
2. create-multiclusterservice.md: Shows how beach-head services can be deployed with a MultiClusterService object. Some portions are shared with ManagedCluster, so those portions refer to the deploy-services-managedcluster.md page.
3. Some additional information about ServiceTemplate in other sections of the docs as appropriate.

I think this is a good start for now for information on beach-head services.

[wahabmk]

@jjainschigg-r Feel free to add Nick Chase as well, I couldn't find his github handle.

[BROngineer]

I'd describe the naming convention for templates we use: template-name-sem-ver-with-dashes, replace concrete versions in provided outputs by X-Y-Z, like cluster-api-X-Y-Z, add separate pages for predefined templates:

• ./pre-defined-provider-templates.md
• ./pre-defined-cluster-templates.md
• ./pre-defined-service-templates.md (Description of bundled beach-head services #66)

where actual versions will be listed. And add references to them, like:

The output should be like the following:

NAME                                 VALID
cluster-api-X-Y-Z                    true
cluster-api-provider-aws-X-Y-Z       true
cluster-api-provider-azure-X-Y-Z     true
cluster-api-provider-vsphere-X-Y-Z   true
hmc-X-Y-Z                            true
k0smotron-X-Y-Z                      true
projectsveltos-X-Y-Z                 true

The actual list of pre-defined templates with versions could be found {link to corresponding file}

I believe it will simplify keeping documentation accurate in the future (for instance cluster template versions example is already outdated).

[BROngineer]

I'd reword it as:

1. MultiClusterService "global-ingress" will take precedence over ManagedCluster "dev-cluster-1" and ingress-nginx (v4.11.3) defined in MultiClusterService object will be deployed on the cluster.
2. ManagedCluster "dev-cluster-2" will take precedence over MultiClusterService "global-ingress" and ingress-nginx (v4.11.0) defined in ManagedCluster object will be deployed on the cluster.

[BROngineer]

Does not related to documentation itself, but need to be fixed asap. Issue: Mirantis/hmc#817