Update template to have bastion section

* Automatically infer bootstrap_os

* Rename bootstrap os to os_family

* Replace `openstack_compute_secgroup_v2` with `openstack_networking_secgroup_v2`

The `openstack_networking_secgroup_v2` resource allow specifications of
both ingress and egress. Nova security groups define ingress rules only.

This change will also allow for more user-friendly specified security
rules, as the different security group resources have different HCL
syntax.

allow masters, nodes and gluster nodes (within each group) to be scheduled
on differents AZ.

Attempting to clarify the language surrounding the etcd node deployment script failure mechanism. I had this error when doing a new cluster deployment last night and, though it should have been, it wasn't immediately apparent to me what was causing the issue (since my default master node hostnames do not specify whether they are also acting as etcd replicas).

This will make NodePort services work out of the box

Add TF_VAR_ to terraform env

* Add supplementary node groups

  To add additional ansible groups to the k8s nodes, such as
  `kube-ingress` for running ingress controller pods. Empty by default.

* [terraform/openstack] Restores ability to use existing public nodes and masters as bastion.

* [terraform/openstack] Uses network_id as output

* [terraform/openstack] Fixes link to inventory/local/group_vars

* [terraform/openstack] Adds supplementary master groups

* [terraform/openstack] Updates documentation avoiding manual setups for bastion (as they are not needed now).

* [terraform/openstack] Supplementary master groups in docs.

* [terraform/openstack] Fixes repeated usage of master fips instead of bastion fips

* [terraform/openstack] Missing change for network_id to subnet_id

* [terraform/openstack] Changes conditional to element( concat ) form to avoid type issues with empty lists.

Supports Kubespray workspace with multiple OpenStack-deployed k8s
clusters.

* Create sample inventory directory for template
* Moved broken `group_vars` symlink to sample directory
* Created sample cluster Terraform file
* Updated documentation

https://www.terraform.io/docs/providers/openstack/r/networking_router_v2.html#external_gateway

Hardcoded variables are removed from variables.tf file because it might
not be suitable for all OpenStack Cloud depending on Identity API
version available (between v2 or v3) and preferred authentication
method.

For distribution who ship python3 as default python, it breaks the
inventory script as it is not compatible with python3.

* Adding bastion and private network provisioning for openstack terraform

* Remove usage of floating-ip property

* Combine openstack instances + floating ips

* Fix relating floating IPs to hosts for openstack builds

* Tighten up security groups

Allow ssh into all instances with floating IP

* Add the gluster hosts to the no-floating group

* Break terraform into modules

* Update README and var descriptions to match current config

* Remove volume property in gluster compute def

* Include cluster name in internal network and router names

* Make dns_nameservers a variable

* Properly tag instances and subnets with `kubernetes.io/cluster/$cluster_name`

This is required by kubernetes to support multiple clusters in a single vpc/az

* Get rid of loadbalancer_apiserver_address as it is no longer needed