OpenShift Dedicated provides a Customer Cloud Subscription (CCS) model that allows Red Hat to deploy and manage clusters into a customer’s existing Amazon Web Service (AWS) account.

Understanding Customer Cloud Subscriptions on AWS

To deploy OpenShift Dedicated into your existing Amazon Web Services (AWS) account using the Customer Cloud Subscription (CCS) model, Red Hat requires several prerequisites be met.

Red Hat recommends the usage of an AWS Organization to manage multiple AWS accounts. The AWS Organization, managed by the customer, hosts multiple AWS accounts. There is a root account in the organization that all accounts will refer to in the account hierarchy.

It is recommended for the OpenShift Dedicated cluster using a CCS model to be hosted in an AWS account within an AWS Organizational Unit. A Service Control Policy (SCP) is created and applied to the AWS Organizational Unit that manages what services the AWS sub-accounts are permitted to access. The SCP applies only to available permissions within a single AWS account for all AWS sub-accounts within the Organizational Unit. It is also possible to apply a SCP to a single AWS account. All other accounts in the customer’s AWS Organization are managed in whatever manner the customer requires. Red Hat Site Reliability Engineers (SRE) will not have any control over SCPs within the AWS Organization.

Customer requirements

OpenShift Dedicated clusters using a Customer Cloud Subscription (CCS) model on Amazon Web Services (AWS) must meet several prerequisites before they can be deployed.

Account

  • The customer ensures that AWS limits are sufficient to support OpenShift Dedicated provisioned within the customer-provided AWS account.

  • The customer-provided AWS account should be in the customer’s AWS Organization with the applicable Service Control Policy (SCP) applied.

    It is not a requirement that the customer-provided account be within an AWS Organization or for the SCP to be applied, however Red Hat must be able to perform all the actions listed in the SCP without restriction.

  • The customer-provided AWS account must not be transferable to Red Hat.

  • The customer may not impose AWS usage restrictions on Red Hat activities. Imposing restrictions severely hinders Red Hat’s ability to respond to incidents.

  • Red Hat deploys monitoring into AWS to alert Red Hat when a highly privileged account, such as a root account, logs into the customer-provided AWS account.

  • The customer can deploy native AWS services within the same customer-provided AWS account.

    Customers are encouraged, but not mandated, to deploy resources in a Virtual Private Cloud (VPC) separate from the VPC hosting OpenShift Dedicated and other Red Hat supported services.

Access requirements

  • To appropriately manage the OpenShift Dedicated service, Red Hat must have the AdministratorAccess policy applied to the administrator role at all times.

    This policy only provides Red Hat with permissions and capabilities to change resources in the customer-provided AWS account.

  • Red Hat must have AWS console access to the customer-provided AWS account. This access is protected and managed by Red Hat.

  • The customer must not utilize the AWS account to elevate their permissions within the OpenShift Dedicated cluster.

  • Actions available in the OpenShift Cluster Manager (OCM) must not be directly performed in the customer-provided AWS account.

Support requirements

  • Red Hat recommends that the customer have at least Business Support from AWS.

  • Red Hat has authority from the customer to request AWS support on their behalf.

  • Red Hat has authority from the customer to request AWS resource limit increases on the customer-provided account.

  • Red Hat manages the restrictions, limitations, expectations, and defaults for all OpenShift Dedicated clusters in the same manner, unless otherwise specified in this requirements section.

Security requirements

  • The customer-provided IAM credentials must be unique to the customer-provided AWS account and must not be stored anywhere in the customer-provided AWS account.

  • Volume snapshots will remain within the customer-provided AWS account and customer-specified region.

  • Red Hat must have ingress access to EC2 hosts and the API server through white-listed Red Hat machines.

  • Red Hat must have egress allowed to forward system and audit logs to a Red Hat managed central logging stack.

Required customer procedure

The Customer Cloud Subscription (CCS) model allows Red Hat to deploy and manage OpenShift Dedicated into a customer’s Amazon Web Services (AWS) account. Red Hat requires several prerequisites in order to provide these services.

Procedure
  1. If the customer is using AWS Organizations, you must either use an AWS account within your organization or create a new one.

  2. To ensure that Red Hat can perform necessary actions, you must either create a Service Control Policy (SCP) or ensure that none is applied to the AWS account.

  3. Attach the SCP to the AWS account.

  4. Within the AWS account, you must create an osdCcsAdmin IAM user with the following requirements:

    • This user needs at least Programmatic access enabled.

    • This user must have the AdministratorAccess policy attached to it.

  5. Provide the IAM user credentials to Red Hat.

Minimum required Service Control Policy (SCP)

Service Control Policy (SCP) management is the responsibility of the customer. These policies are maintained in the AWS Organization and control what services are available within the attached AWS accounts.

Required/optional Service Actions Effect

Required

Amazon EC2

All

Allow

Amazon EC2 Auto Scaling

All

Allow

Amazon S3

All

Allow

Identity And Access Management

All

Allow

Elastic Load Balancing

All

Allow

Elastic Load Balancing V2

All

Allow

Amazon CloudWatch

All

Allow

Amazon CloudWatch Events

All

Allow

Amazon CloudWatch Logs

All

Allow

AWS Support

All

Allow

AWS Key Management Service

All

Allow

AWS Security Token Service

All

Allow

AWS Resource Tagging

All

Allow

AWS Route53 DNS

All

Allow

AWS Service Quotas

ListServices

GetRequestedServiceQuotaChange

GetServiceQuota

RequestServiceQuotaIncrease

ListServiceQuotas

Allow

Optional

AWS Billing

ViewAccount

Viewbilling

ViewUsage

Allow

AWS Cost and Usage Report

All

Allow

AWS Cost Explorer Services

All

Allow

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "autoscaling:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "s3:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "iam:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticloadbalancing:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "cloudwatch:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "events:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "logs:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "support:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "kms:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "sts:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "tag:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "route53:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "servicequotas:ListServices",
                "servicequotas:GetRequestedServiceQuotaChange",
                "servicequotas:GetServiceQuota",
                "servicequotas:RequestServiceQuotaIncrease",
                "servicequotas:ListServiceQuotas"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}

Red Hat managed IAM references for AWS

Red Hat is responsible for creating and managing the following Amazon Web Services (AWS) resources: IAM policies, IAM users, and IAM roles.

IAM policies

IAM policies are subject to modification as the capabilities of OpenShift Dedicated change.

  • The AdministratorAccess policy is used by the administration role. This policy provides Red Hat the access necessary to administer the OpenShift Dedicated cluster in the customer-provided AWS account.

    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Action": "*",
                "Resource": "*",
                "Effect": "Allow"
            }
        ]
    }
  • The CustomerAdministatorAccess role provides the customer access to administer a subset of services within the AWS account. At this time, the following are allowed:

    • VPC Peering

    • VPN Setup

    • Direct Connect (only available if granted through the Service Control Policy)

      {
          "Version": "2012-10-17",
          "Statement": [
              {
                  "Effect": "Allow",
                  "Action": [
                      "ec2:AttachVpnGateway",
                      "ec2:DescribeVpnConnections",
                      "ec2:AcceptVpcPeeringConnection",
                      "ec2:DeleteVpcPeeringConnection",
                      "ec2:DescribeVpcPeeringConnections",
                      "ec2:CreateVpnConnectionRoute",
                      "ec2:RejectVpcPeeringConnection",
                      "ec2:DetachVpnGateway",
                      "ec2:DeleteVpnConnectionRoute",
                      "ec2:DeleteVpnGateway",
                      "ec2:DescribeVpcs",
                      "ec2:CreateVpnGateway",
                      "ec2:ModifyVpcPeeringConnectionOptions",
                      "ec2:DeleteVpnConnection",
                      "ec2:CreateVpcPeeringConnection",
                      "ec2:DescribeVpnGateways",
                      "ec2:CreateVpnConnection",
                      "ec2:DescribeRouteTables",
                      "ec2:CreateTags",
                      "ec2:CreateRoute",
                "directconnect:*"
                  ],
                  "Resource": "*"
              }
          ]
      }
  • If enabled, the BillingReadOnlyAccess role provides read-only access to view billing and usage information for the account.

    Billing and usage access is only granted if the root account in the AWS Organization has it enabled. This is an optional step the customer must perform to enable read-only billing and usage access and does not impact the creation of this profile and the role that uses it. If this role is not enabled, users will not see billing and usage information. See this tutorial on how to enable access to billing data.

    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": [
                    "aws-portal:ViewAccount",
                    "aws-portal:ViewBilling"
                ],
                "Resource": "*"
            }
        ]
    }

IAM users

The osdManagedAdmin user is created immediately after taking control of the customer-provided AWS account. This is the user that will perform the OpenShift Dedicated cluster installation.

IAM roles

  • The network-mgmt role provides customer-federated administrative access to the AWS account through a separate AWS account. It also has the same access as a read-only role. The following policies are attached to the role:

    • AmazonEC2ReadOnlyAccess

    • CustomerAdministratorAccess

  • The read-only role provides customer-federated read-only access to the AWS account through a separate AWS account. The following policies are attached to the role:

    • AWSAccountUsageReportAccess

    • AmazonEC2ReadOnlyAccess

    • AmazonS3ReadOnlyAccess

    • IAMReadOnlyAccess

    • BillingReadOnlyAccess

Provisioned AWS Infrastructure

This is an overview of the provisioned Amazon Web Services (AWS) components on a deployed OpenShift Dedicated cluster. For a more detailed listing of all provisioned AWS components, see the OpenShift Container Platform documentation.

AWS Elastic Computing (EC2) instances

AWS EC2 instances are required to deploy the control plane and data plane functions of OpenShift Dedicated in the AWS public cloud. Instance types might vary for control plane and infrastructure nodes depending on worker node count.

  • Single availability zone

    • 3 m5.xlarge minimum (control plane nodes)

    • 2 r5.xlarge minimum (infrastructure nodes)

    • 2 m5.xlarge minimum but highly variable (worker nodes)

  • Multiple availability zones

    • 3 m5.xlarge minimum (control plane nodes)

    • 3 r5.xlarge minimum (infrastructure nodes)

    • 3 m5.xlarge minimum but highly variable (worker nodes)

AWS Elastic Block Store (EBS) storage

Amazon EBS block storage is used for both local node storage and persistent volume storage.

Volume requirements for each EC2 instance:

  • Control plane volumes

    • Size: 350 GB

    • Type: io1

    • Input/output operations per second: 1000

  • Infrastructure volumes

    • Size: 300 GB

    • Type: gp2

    • Input/output operations per second: 100

  • Worker volumes

    • Size: 300 GB

    • Type: gp2

    • Input/output operations per second: 100

Elastic load balancers

Up to two Network Elastic Load Balancers (ELBs) for API and up to two Classic ELBs for application router. For more information, see the ELB documentation for AWS.

S3 storage

The image registry and Elastic Block Store (EBS) volume snapshots are backed by AWS S3 storage. Pruning of resources is performed regularly to optimize S3 usage and cluster performance.

Two buckets are required with a typical size of 2 TB each.

VPC

Customers should expect to see one VPC per cluster. Additionally, the VPC needs the following configurations:

  • Subnets: Two subnets for a cluster with a single availability zone, or six subnets for a cluster with multiple availability zones.

  • Router tables: One router table per private subnet, and one additional table per cluster.

  • Internet gateways: One Internet Gateway per cluster.

  • NAT gateways: One NAT Gateway per public subnet.

Security groups

AWS security groups provide security at the protocol and port-access level; they are associated with EC2 instances and Elastic Load Balancing. Each security group contains a set of rules that filter traffic coming in and out of an EC2 instance. You must ensure the ports required for the OpenShift Container Platform installation are open on your network and configured to allow access between hosts.

AWS account limits

The OpenShift Dedicated cluster uses a number of Amazon Web Services (AWS) components, and the default service limits affect your ability to install OpenShift Dedicated clusters. If you use certain cluster configurations, deploy your cluster in certain AWS regions, or run multiple clusters from your account, you might need to request additional resources for your AWS account.

The following table summarizes the AWS components whose limits can impact your ability to install and run OpenShift Dedicated clusters.

Component Number of clusters available by default Default AWS limit Description

Instance Limits

Varies

Varies

By default, each cluster creates the following instances:

  • One bootstrap machine, which is removed after installation

  • Three master nodes

  • Three worker nodes

These instance type counts are within a new account’s default limit. To deploy more worker nodes, enable autoscaling, deploy large workloads, or use a different instance type, review your account limits to ensure that your cluster can deploy the machines that you need.

In most regions, the bootstrap and worker machines uses an m4.large machines and the master machines use m4.xlarge instances. In some regions, including all regions that do not support these instance types, m5.large and m5.xlarge instances are used instead.

Elastic IPs (EIPs)

0 to 1

5 EIPs per account

To provision the cluster in a highly available configuration, the installation program creates a public and private subnet for each availability zone within a region. Each private subnet requires a NAT Gateway, and each NAT gateway requires a separate elastic IP. Review the AWS region map to determine how many availability zones are in each region. To take advantage of the default high availability, install the cluster in a region with at least three availability zones. To install a cluster in a region with more than five availability zones, you must increase the EIP limit.

To use the us-east-1 region, you must increase the EIP limit for your account.

Virtual Private Clouds (VPCs)

5

5 VPCs per region

Each cluster creates its own VPC.

Elastic Load Balancing (ELB/NLB)

3

20 per region

By default, each cluster creates internal and external network load balancers for the master API server and a single classic elastic load balancer for the router. Deploying more Kubernetes LoadBalancer Service objects will create additional load balancers.

NAT Gateways

5

5 per availability zone

The cluster deploys one NAT gateway in each availability zone.

Elastic Network Interfaces (ENIs)

At least 12

350 per region

The default installation creates 21 ENIs and an ENI for each availability zone in your region. For example, the us-east-1 region contains six availability zones, so a cluster that is deployed in that zone uses 27 ENIs. Review the AWS region map to determine how many availability zones are in each region.

Additional ENIs are created for additional machines and elastic load balancers that are created by cluster usage and deployed workloads.

VPC Gateway

20

20 per account

Each cluster creates a single VPC Gateway for S3 access.

S3 buckets

99

100 buckets per account

Because the installation process creates a temporary bucket and the registry component in each cluster creates a bucket, you can create only 99 OpenShift Dedicated clusters per AWS account.

Security Groups

250

2,500 per account

Each cluster creates 10 distinct security groups.