4.4.5 Required machines
A standard OpenShift Container Platform installation creates the following vCenter resources:
• 1 Folder
• 1 Tag category
• 1 Tag
• Virtual machines:
o 1 template
o 1 temporary bootstrap node
o 3 control plane nodes
o 3 compute machines
4.4.6 Network connectivity requirements
A DHCP server must be used for the network, so ensure that this DHCP server is configured to provide persistent IP addresses to the cluster machines. The VMware WorkStation Pro host supports the DHCP functionality here. Additionally, the following networking resources must be created before installation of the OpenShift Container Platform cluster:
Each OpenShift Container Platform node in the cluster must, ideally, has access to a Network Time Protocol (NTP) server accessible using DHCP. Installation works without an NTP server, but if the server clocks are not synchronized errors will occur.
Each node of the server cluster requires two static IP addresses:
The API address is used to access the cluster API.
The Ingress address is used for cluster ingress network traffic.
The required IP addresses have to be entered during the installation of the OpenShift Container Platform cluster. DNS records for two static IP addresses are required in a DNS server for the OpenShift Container Platform cluster.
In each record, <cluster_name>is the cluster name and is the cluster base domain that is specified during cluster installation.
A complete DNS record is in the format: <component>.<cluster_name>.<base_domain>..
The required entries in the DNS server record are as follows:
Note that both records must be resolvable by both external and internal cluster client systems from all the cluster nodes.
api.<cluster_name>.<base_domain>.
This DNS A/AAAA or CNAME record points to the load balancer for the control plane machines. Ingress VIP:
*.apps.<cluster_name>.<base_domain>.
This is a wildcard DNS A/AAAA or CNAME record that points to the load balancer that targets the machines running the Ingress pods. By default, these are the worker nodes.
4.4.7 Certificate signing requests
This is covered in detail in the BPB Publications book, IBM DB2 Administration Guide, Chapter 2, On-Premise Server Configurations and Prerequisites, section 2.3.11 Generating an SSH private key (ISBN 978-93-55511-669).
4.4.8 Creating the user-provisioned infrastructure
This is covered in detail in the BPB Publications book, IBM DB2 Administration Guide, Chapter 2, On-Premise Server Configurations and Prerequisites, section 2.3.2: Machine requirements for a cluster (ISBN 978-93-55511-669).