Chapter 2. Selecting a cluster installation method and preparing it for users
Before you install OpenShift Container Platform, decide what kind of installation process to follow and make sure you that you have all of the required resources to prepare the cluster for users.
2.1. Selecting a cluster installation type
Before you install an OpenShift Container Platform cluster, you need to select the best installation instructions to follow. Think about your answers to the following questions to select the best option.
2.1.1. Do you want to install and manage an OpenShift Container Platform cluster yourself?
If you want to install and manage OpenShift Container Platform yourself, you can install it on the following platforms:
- Amazon Web Services (AWS)
- Microsoft Azure
- Google Cloud Platform (GCP)
- IBM Z and LinuxONE
- IBM Power
- VMware vSphere
- VMware Cloud (VMC) on AWS
- Bare metal or other platform agnostic infrastructure
You can deploy an OpenShift Container Platform 4 cluster to both on-premise hardware and to cloud hosting services, but all of the machines in a cluster must be in the same datacenter or cloud hosting service.
If you want to use OpenShift Container Platform but do not want to manage the cluster yourself, you have several managed service options. If you want a cluster that is fully managed by Red Hat, you can use OpenShift Dedicated or OpenShift Online. You can also use OpenShift as a managed service on Azure, AWS, IBM Cloud, or Google Cloud. For more information about managed services, see the OpenShift Products page.
2.1.2. Have you used OpenShift Container Platform 3 and want to use OpenShift Container Platform 4?
If you used OpenShift Container Platform 3 and want to try OpenShift Container Platform 4, you need to understand how different OpenShift Container Platform 4 is. OpenShift Container Platform 4 weaves the Operators that package, deploy, and manage Kubernetes applications and the operating system that the platform runs on, Red Hat Enterprise Linux CoreOS (RHCOS), together seamlessly. Instead of deploying machines and configuring their operating systems so that you can install OpenShift Container Platform on them, the RHCOS operating system is an integral part of the OpenShift Container Platform cluster. Deploying the operating system for the cluster machines as part of the installation process for OpenShift Container Platform. See Comparing OpenShift Container Platform 3 and OpenShift Container Platform 4.
Because you need to provision machines as part of the OpenShift Container Platform cluster installation process, you cannot upgrade an OpenShift Container Platform 3 cluster to OpenShift Container Platform 4. Instead, you must create a new OpenShift Container Platform 4 cluster and migrate your OpenShift Container Platform 3 workloads to them. For more information about migrating, see OpenShift Migration Best Practices. Because you must migrate to OpenShift Container Platform 4, you can use any type of production cluster installation process to create your new cluster.
2.1.3. Do you want to use existing components in your cluster?
Because the operating system is integral to OpenShift Container Platform, it is easier to let the installation program for OpenShift Container Platform stand up all of the infrastructure. These are called installer provisioned infrastructure installations. In this type of installation, you can provide some existing infrastructure to the cluster, but the installation program deploys all of the machines that your cluster initially needs.
You can deploy an installer-provisioned infrastructure cluster without specifying any customizations to the cluster or its underlying machines to AWS, Azure, or GCP. These installation methods are the fastest way to deploy a production-capable OpenShift Container Platform cluster.
If you need to perform basic configuration for your installer-provisioned infrastructure cluster, such as the instance type for the cluster machines, you can customize an installation for AWS, Azure, or GCP.
For installer-provisioned infrastructure installations, you can use an existing VPC in AWS, vNet in Azure, or VPC in GCP. You can also reuse part of your networking infrastructure so that your cluster in AWS, Azure, or GCP can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations. If you have existing accounts and credentials on these clouds, you can re-use them, but you might need to modify the accounts to have the required permissions to install OpenShift Container Platform clusters on them.
If you want to reuse extensive cloud infrastructure, you can complete a user-provisioned infrastructure installation. With these installations, you manually deploy the machines that your cluster requires during the installation process. If you perform a user-provisioned infrastructure installation on AWS, Azure, or GCP, you can use the provided templates to help you stand up all of the required components. Otherwise, you can use the provider-agnostic installation method to deploy a cluster into other clouds.
You can also complete a user-provisioned infrastructure installation on your existing hardware. If you use RHOSP, RHV, IBM Z or LinuxONE, IBM Power, or vSphere, use the specific installation instructions to deploy your cluster. If you use other supported hardware, follow the bare metal installation procedure.
2.1.4. Do you need extra security for your cluster?
If you use a user-provisioned installation method, you can configure a proxy for your cluster. The instructions are included in each installation procedure.
If you need to install your cluster that has limited access to the Internet, such as a disconnected or restricted network cluster, you can mirror the installation packages and install the cluster from them. Follow detailed instructions for user provisioned infrastructure installations into restricted networks for AWS, GCP, IBM Z or LinuxONE, IBM Power, vSphere, or bare metal.
You can also configure the cluster machines to use FIPS Validated / Modules in Process cryptographic libraries during installation.
2.2. Preparing your cluster for users after installation
Some configuration is not required to install the cluster but recommended before your users access the cluster. You can customize the cluster itself by customizing the Operators that make up your cluster and integrate you cluster with other required systems, such as an identity provider.
For a production cluster, you must configure the following integrations:
2.3. Preparing your cluster for workloads
Depending on your workload needs, you might need to take extra steps before you begin deploying applications. For example, after you prepare infrastructure to support your application build strategy, you might need to make provisions for low-latency workloads or to protect sensitive workloads. You can also configure monitoring for application workloads. If you plan to run Windows workloads, you must enable hybrid networking with OVN-Kubernetes during the installation process; hybrid networking cannot be enabled after your cluster is installed.
2.4. Supported installation methods for different platforms
You can perform different types of installations on different platforms.
Not all installation options are supported for all platforms, as shown in the following tables.
Table 2.1. Installer-provisioned infrastructure options