Removed the requirement for worker nodes.

Author: johnwilkins

installing/installing_bare_metal_ipi/ipi-install-installation-workflow.adoc

@@ -5,7 +5,7 @@ include::modules/common-attributes.adoc[]
 
 toc::[]
 
-include::modules/ipi-install-installing-rhel-on-the-provision-node.adoc[leveloffset=+1]
+include::modules/ipi-install-installing-rhel-on-the-provisioner-node.adoc[leveloffset=+1]
 
 include::modules/ipi-install-preparing-the-provisioner-node-for-openshift-install.adoc[leveloffset=+1]
 

installing/installing_bare_metal_ipi/ipi-install-prerequisites.adoc

@@ -10,7 +10,6 @@ Installer-provisioned installation of {product-title} requires:
 
 . One provisioner node with RHEL 8.1 installed.
 . Three Control Plane nodes.
-. At least two worker nodes.
 . Baseboard Management Controller (BMC) access to each node.
 ifeval::[{release} > 4.5]
 . At least one network:

modules/ipi-install-installing-rhel-on-the-provision-node.adoc

@@ -0,0 +1,8 @@
+// Module included in the following assemblies:
+//
+// * list of assemblies where this module is included
+// ipi-install-installation-workflow.adoc
+[id="installing-rhel-on-the-provisioner-node_{context}"]
+= Installing RHEL on the provisioner node
+
+With the networking configuration complete, the next step is to install {op-system-base} 8.x on the provisioner node. The installer uses the provisioner node as the orchestrator while installing the {product-title} cluster. For the purposes of this document, installing RHEL on the provisioner node is out of scope. However, options include but are not limited to using a RHEL Satellite server, PXE, or installation media.

modules/ipi-install-installing-rhel-on-the-provisioner-node.adoc

@@ -5,7 +5,7 @@
 [id='network-requirements_{context}']
 = Network requirements
 
-Installer-provisioned installation of {product-title} involves several network requirements by default. First, installer-provisioned installation involves a non-routable `provisioning` network for provisioning the OS on each bare metal node and a routable `baremetal` network. Since installer-provisioned installation deploys `ironic-dnsmasq`, the networks should have no other DHCP servers running on the same broadcast domain. Network administrators *must* reserve IP addresses for each node in the {product-title} cluster.
+Installer-provisioned installation of {product-title} involves several network requirements by default. First, installer-provisioned installation involves a non-routable `provisioning` network for provisioning the operating system on each bare metal node and a routable `baremetal` network. Since installer-provisioned installation deploys `ironic-dnsmasq`, the networks should have no other DHCP servers running on the same broadcast domain. Network administrators must reserve IP addresses for each node in the {product-title} cluster.
 
 .Network Time Protocol (NTP)
 
@@ -40,18 +40,35 @@ For example:
 test-cluster.example.com
 ----
 
+ifdef::upstream[]
+For assistance in configuring the DNS server, check xref:ipi-install-upstream-appendix[Appendix] section for:
+
+- xref:creating-dns-records-on-a-dns-server-option1_{context}[Creating DNS Records with Bind (Option 1)]
+- xref:creating-dns-records-using-dnsmasq-option2_{context}[Creating DNS Records with dnsmasq (Option 2)]
+
+endif::[]
+
+
 .Reserving IP Addresses for Nodes with the DHCP Server
 
 For the `baremetal` network, a network administrator must reserve a number of IP addresses, including:
 
+ifeval::[{release} > 4.5]
 . Two virtual IP addresses.
+endif::[]
+ifeval::[{release} <= 4.5]
+. Three virtual IP addresses
+endif::[]
 +
-- 1 IP address for the API endpoint
-- 1 IP address for the wildcard ingress endpoint
+- One IP address for the API endpoint
+- One IP address for the wildcard ingress endpoint
+ifeval::[{release} <= 4.5]
+- One IP address for the name server
+endif::[]
 
-. One IP Address for the provisioner node.
-. One IP address for each Control Plane (Master) node.
-. One IP address for each worker node.
+. One IP address for the provisioner node.
+. One IP address for each control plane (master) node.
+. One IP address for each worker node, if applicable.
 
 
 The following table provides an exemplary embodiment of hostnames for each node in the {product-title} cluster.
@@ -61,6 +78,9 @@ The following table provides an exemplary embodiment of hostnames for each node
 | Usage | Hostname | IP
 | API | api.<cluster-name>.<domain> | <ip>
 | Ingress LB (apps) |  *.apps.<cluster-name>.<domain>  | <ip>
+ifeval::[{release} <= 4.5]
+| Nameserver | ns1.<cluster-name>.<domain> | <ip>
+endif::[]
 | Provisioner node | provisioner.<cluster-name>.<domain> | <ip>
 | Master-0 | openshift-master-0.<cluster-name>.<domain> | <ip>
 | Master-1 | openshift-master-1.<cluster-name>-.<domain> | <ip>
@@ -70,6 +90,13 @@ The following table provides an exemplary embodiment of hostnames for each node
 | Worker-n | openshift-worker-n.<cluster-name>.<domain> | <ip>
 |=====
 
+ifdef::upstream[]
+For assistance in configuring the DHCP server, check xref:ipi-install-upstream-appendix[Appendix] section for:
+
+- xref:creating-dhcp-reservations-option1_{context}[Creating DHCP reservations with dhcpd (Option 1)]
+- xref:creating-dhcp-reservations-using-dnsmasq-option2_{context}[Creating DHCP reservations with dnsmasq (Option 2)]
+endif::[]
+
 .Additional requirements with no provisioning network
 
 All installer-provisioned installations require a `baremetal` network. The `baremetal` network is a routable network used for external network access to the outside world. In addition to the IP address supplied to the {product-title} cluster node, installations without a `provisioning` network require the following:

modules/ipi-install-network-requirements.adoc

@@ -28,7 +28,7 @@ endif::[]
 
 - **Control plane:** Installer-provisioned installation requires three control plane nodes for high availability.
 
-- **Worker nodes:** A typical production cluster will have many worker nodes. Installer-provisioned installation in a high availability environment requires at least two worker nodes in an initial cluster.
+- **Worker nodes:** While not required, a typical production cluster has one or more worker nodes. Smaller clusters are more resource efficient for administrators and developers during development and testing. 
 
 - **Network interfaces:** Each node must have at least one 10GB network interface for the routable `baremetal` network. Each node must have one 10GB network interface for a `provisioning` network *when using the `provisioning` network* for deployment. Using the `provisioning` network is the default configuration. Network interface names must follow the same naming convention across all nodes. For example, the first NIC name on a node, such as `eth0` or `eno1`, must be the same name on all of the other nodes. The same principle applies to the remaining NICs on each node.