Add pages for new OpenShift on OpenStack provider

The new shift-on-stack provider [0] complements and will replace some of
the existing documentation and reference architectures for OCP 3.4/3.6
on OSP 10. It is planned to be the supported solution in the OSP 13 time frame.

[0] https://github.com/openshift/openshift-ansible-contrib

Changes:

* Clarify on-premises and cloud providers cases in
  the Getting Started, Planning and Advanced Installation pages for
  the openshift-origin/enterprise distros.
* Link documentation pages for the shift-on-stack provider, which
  is currently hosted in-repo docs.
* Add links for published OCP on OSP ref. architectures
* Add a deprecation note for OCP 3.4 on OSP 10 reference
  architecture based on Heat Templates.

Note that the new provider is being moved under the openshift-ansible
repo [1]. The links must be updated after the documentation moved as
the part of that change request.
"Configuring OpenShift Origin for OpenStack with Ansible" will likely
need some updates as well.

[1] openshift/openshift-ansible#5797 .

Signed-off-by: Bogdan Dobrelya <[email protected]>

Author: bogdando

getting_started/administrators.adoc

@@ -40,6 +40,19 @@ networking. Ensure that local firewall rules and other software making iptable
 changes do not alter the {product-title} and Docker service setup.
 ====
 
+ifdef::openshift-origin[]
+
+[[get-started-cloud-providers]]
+=== On-premises vs Cloud Providers
+
+{product-title} can be installed on-premises or hosted on public or private
+clouds. For more details,
+xref:../install_config/install/advanced_install.adoc#advanced-cloud-providers[see the advanced installation guide].
+
+Once you have your cluster nodes provisioned, choose the
+installation method that fits your case the best.
+endif::[]
+
 [[installation-methods]]
 == Installation Methods
 

install_config/install/advanced_install.adoc

@@ -71,9 +71,49 @@ see the
 xref:../../scaling_performance/install_practices.adoc#scaling-performance-install-best-practices[Scaling and Performance Guide].
 
 After following the instructions in the
-xref:../../install_config/install/prerequisites.adoc#install-config-install-prerequisites[Prerequisites] topic and
-deciding between the RPM and containerized methods, you can continue in this
-topic to xref:configuring-ansible[Configuring Ansible Inventory Files].
+xref:../../install_config/install/prerequisites.adoc#install-config-install-prerequisites[Prerequisites]
+topic, deciding between the RPM and containerized methods and
+xref:advanced-cloud-providers[choosing from the on-premises or cloud scenarios],
+you can continue in this topic to
+xref:configuring-ansible[Configuring Ansible Inventory Files].
+
+[[advanced-cloud-providers]]
+=== Choosing clouds over on-premises
+
+Provisioning of VMs in a cloud, defining your cloud infrastructure and applying
+the required post-provision configuration tasks may be assisted with Ansible
+automation playbooks for the supported cloud providers. This advanced installation
+guide is happen to fulfill that purpose as well.
+
+==== OpenStack provider
+
+In order to install {product-title} with manual steps using OpenStack CLI,
+see the
+link:https://access.redhat.com/documentation/en-us/reference_architectures/2017/html-single/deploying_and_managing_red_hat_openshift_container_platform_3.6_on_red_hat_openstack_platform_10[reference architecture],
+which is actual for {product-title} 3.6 and Red Hat OpenStack Platform 10.
+
+As a prerequisite, you will have to provision VMs and configure the cloud
+infrastructure, like network, storage, firewall and security groups.
+Some of the basic configuration may be assisted by that reference architecture
+and the
+xref:../../install_config/install/prerequisites#prereq-cloud-provider-considerations[cloud provider considerations].
+For advanced configuration prerequisites, like DNS, load balancing and high
+availability, you may want to use the
+link:https://github.com/openshift/openshift-ansible-contrib/tree/master/playbooks/provisioning/openstack[Ansible automation playbooks]
+instead. For automated installations, see also
+xref:../../install_config/configuring_openstack#install-config-configuring-openstack[Configuring for OpenStack]
+and
+xref:configuring-ansible[Configuring Ansible Inventory Files].
+
+====
+[IMPORTANT]
+The reference architecture for automated installations based on
+link:https://docs.openstack.org/heat/latest[OpenStack Heat] templates for
+link:https://access.redhat.com/documentation/en-us/reference_architectures/2017/html/deploying_red_hat_openshift_container_platform_3.4_on_red_hat_openstack_platform_10[{product-title} (OCP 3.4) on Red Hat OpenStack Platform 10]
+is deprecated. For OSP 13 time frame, it is being replaced with the
+link:https://github.com/openshift/openshift-ansible-contrib/tree/master/playbooks/provisioning/openstack[Ansible driven deployment solution].
+For automated installations, please follow that guide instead!
+====
 
 [[configuring-ansible]]
 == Configuring Ansible Inventory Files

install_config/install/planning.adoc

@@ -17,6 +17,9 @@ toc::[]
 For production environments, several factors influence installation. Consider
 the following questions as you read through the documentation:
 
+* _Do you install on-premises or in public/private clouds?_ The xref:planning-cloud-providers[Installation Methods]
+section provides more information about the cloud providers options available.
+
 * _Which installation method do you want to use?_ The xref:installation-methods[Installation Methods]
 section provides some information about the quick and advanced installation
 methods.
@@ -65,6 +68,14 @@ the same installer tool. If you wanted to later switch to using the advanced
 method, you can create an inventory file for your configuration and carry on
 that way.
 
+[[planning-cloud-providers]]
+=== On-premises vs Cloud Providers
+
+{product-title} can be installed on-premises or hosted on public or private
+clouds. The aforementioned Ansible playbooks will help you with automation of
+the provisioning and installation processes. For more details,
+xref:../../install_config/install/advanced_install.adoc#advanced-cloud-providers[see the advanced installation guide].
+
 [[sizing]]
 == Sizing Considerations