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Hosted control planes

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OpenShift Container Platform 4.15

Using hosted control planes with OpenShift Container Platform

Red Hat OpenShift Documentation Team

Abstract

This document provides instructions for managing hosted control planes for OpenShift Container Platform. With hosted control planes, you create control planes as pods on a hosting cluster without the need for dedicated physical or virtual machines for each control plane.

Chapter 1. Hosted control planes overview

You can deploy OpenShift Container Platform clusters by using two different control plane configurations: standalone or hosted control planes. The standalone configuration uses dedicated virtual machines or physical machines to host the control plane. With hosted control planes for OpenShift Container Platform, you create control planes as pods on a hosting cluster without the need for dedicated virtual or physical machines for each control plane.

1.1. Glossary of common concepts and personas for hosted control planes

When you use hosted control planes for OpenShift Container Platform, it is important to understand its key concepts and the personas that are involved.

1.1.1. Concepts

hosted cluster
An OpenShift Container Platform cluster with its control plane and API endpoint hosted on a management cluster. The hosted cluster includes the control plane and its corresponding data plane.
hosted cluster infrastructure
Network, compute, and storage resources that exist in the tenant or end-user cloud account.
hosted control plane
An OpenShift Container Platform control plane that runs on the management cluster, which is exposed by the API endpoint of a hosted cluster. The components of a control plane include etcd, the Kubernetes API server, the Kubernetes controller manager, and a VPN.
hosting cluster
See management cluster.
managed cluster
A cluster that the hub cluster manages. This term is specific to the cluster lifecycle that the multicluster engine for Kubernetes Operator manages in Red Hat Advanced Cluster Management. A managed cluster is not the same thing as a management cluster. For more information, see Managed cluster.
management cluster
An OpenShift Container Platform cluster where the HyperShift Operator is deployed and where the control planes for hosted clusters are hosted. The management cluster is synonymous with the hosting cluster.
management cluster infrastructure
Network, compute, and storage resources of the management cluster.
node pool
A resource that contains the compute nodes. The control plane contains node pools. The compute nodes run applications and workloads.

1.1.2. Personas

cluster instance administrator
Users who assume this role are the equivalent of administrators in standalone OpenShift Container Platform. This user has the cluster-admin role in the provisioned cluster, but might not have power over when or how the cluster is updated or configured. This user might have read-only access to see some configuration projected into the cluster.
cluster instance user
Users who assume this role are the equivalent of developers in standalone OpenShift Container Platform. This user does not have a view into OperatorHub or machines.
cluster service consumer
Users who assume this role can request control planes and worker nodes, drive updates, or modify externalized configurations. Typically, this user does not manage or access cloud credentials or infrastructure encryption keys. The cluster service consumer persona can request hosted clusters and interact with node pools. Users who assume this role have RBAC to create, read, update, or delete hosted clusters and node pools within a logical boundary.
cluster service provider

Users who assume this role typically have the cluster-admin role on the management cluster and have RBAC to monitor and own the availability of the HyperShift Operator as well as the control planes for the tenant’s hosted clusters. The cluster service provider persona is responsible for several activities, including the following examples:

  • Owning service-level objects for control plane availability, uptime, and stability
  • Configuring the cloud account for the management cluster to host control planes
  • Configuring the user-provisioned infrastructure, which includes the host awareness of available compute resources

1.2. Introduction to hosted control planes

You can use hosted control planes for Red Hat OpenShift Container Platform to reduce management costs, optimize cluster deployment time, and separate management and workload concerns so that you can focus on your applications.

Hosted control planes is available by using the multicluster engine for Kubernetes Operator version 2.0 or later on the following platforms:

  • Bare metal by using the Agent provider
  • OpenShift Virtualization, as a Generally Available feature in connected environments and a Technology Preview feature in disconnected environments
  • Amazon Web Services (AWS), as a Technology Preview feature
  • IBM Z, as a Technology Preview feature
  • IBM Power, as a Technology Preview feature

1.2.1. Architecture of hosted control planes

OpenShift Container Platform is often deployed in a coupled, or standalone, model, where a cluster consists of a control plane and a data plane. The control plane includes an API endpoint, a storage endpoint, a workload scheduler, and an actuator that ensures state. The data plane includes compute, storage, and networking where workloads and applications run.

The standalone control plane is hosted by a dedicated group of nodes, which can be physical or virtual, with a minimum number to ensure quorum. The network stack is shared. Administrator access to a cluster offers visibility into the cluster’s control plane, machine management APIs, and other components that contribute to the state of a cluster.

Although the standalone model works well, some situations require an architecture where the control plane and data plane are decoupled. In those cases, the data plane is on a separate network domain with a dedicated physical hosting environment. The control plane is hosted by using high-level primitives such as deployments and stateful sets that are native to Kubernetes. The control plane is treated as any other workload.

Diagram that compares the hosted control plane model against OpenShift with a coupled control plane and workers

1.2.2. Benefits of hosted control planes

With hosted control planes for OpenShift Container Platform, you can pave the way for a true hybrid-cloud approach and enjoy several other benefits.

  • The security boundaries between management and workloads are stronger because the control plane is decoupled and hosted on a dedicated hosting service cluster. As a result, you are less likely to leak credentials for clusters to other users. Because infrastructure secret account management is also decoupled, cluster infrastructure administrators cannot accidentally delete control plane infrastructure.
  • With hosted control planes, you can run many control planes on fewer nodes. As a result, clusters are more affordable.
  • Because the control planes consist of pods that are launched on OpenShift Container Platform, control planes start quickly. The same principles apply to control planes and workloads, such as monitoring, logging, and auto-scaling.
  • From an infrastructure perspective, you can push registries, HAProxy, cluster monitoring, storage nodes, and other infrastructure components to the tenant’s cloud provider account, isolating usage to the tenant.
  • From an operational perspective, multicluster management is more centralized, which results in fewer external factors that affect the cluster status and consistency. Site reliability engineers have a central place to debug issues and navigate to the cluster data plane, which can lead to shorter Time to Resolution (TTR) and greater productivity.

1.3. Relationship between hosted control planes, multicluster engine Operator, and RHACM

You can configure hosted control planes by using the multicluster engine for Kubernetes Operator. The multicluster engine is an integral part of Red Hat Advanced Cluster Management (RHACM) and is enabled by default with RHACM. The multicluster engine Operator cluster lifecycle defines the process of creating, importing, managing, and destroying Kubernetes clusters across various infrastructure cloud providers, private clouds, and on-premises data centers.

The multicluster engine Operator is the cluster lifecycle Operator that provides cluster management capabilities for OpenShift Container Platform and RHACM hub clusters. The multicluster engine Operator enhances cluster fleet management and supports OpenShift Container Platform cluster lifecycle management across clouds and data centers.

Figure 1.1. Cluster life cycle and foundation

Cluster life cycle and foundation

You can use the multicluster engine Operator with OpenShift Container Platform as a standalone cluster manager or as part of a RHACM hub cluster.

Tip

A management cluster is also known as the hosting cluster.

You can deploy OpenShift Container Platform clusters by using two different control plane configurations: standalone or hosted control planes. The standalone configuration uses dedicated virtual machines or physical machines to host the control plane. With hosted control planes for OpenShift Container Platform, you create control planes as pods on a management cluster without the need for dedicated virtual or physical machines for each control plane.

Figure 1.2. RHACM and the multicluster engine Operator introduction diagram

RHACM and the multicluster engine Operator introduction diagram

1.4. Versioning for hosted control planes

With each major, minor, or patch version release of OpenShift Container Platform, two components of hosted control planes are released:

  • The HyperShift Operator
  • The hcp command-line interface (CLI)

The HyperShift Operator manages the lifecycle of hosted clusters that are represented by the HostedCluster API resources. The HyperShift Operator is released with each OpenShift Container Platform release. The HyperShift Operator creates the supported-versions config map in the hypershift namespace. The config map contains the supported hosted cluster versions.

You can host different versions of control planes on the same management cluster.

Example supported-versions config map object

    apiVersion: v1
    data:
      supported-versions: '{"versions":["4.15"]}'
    kind: ConfigMap
    metadata:
      labels:
        hypershift.openshift.io/supported-versions: "true"
      name: supported-versions
      namespace: hypershift

You can use the hcp CLI to create hosted clusters.

You can use the hypershift.openshift.io API resources, such as, HostedCluster and NodePool, to create and manage OpenShift Container Platform clusters at scale. A HostedCluster resource contains the control plane and common data plane configuration. When you create a HostedCluster resource, you have a fully functional control plane with no attached nodes. A NodePool resource is a scalable set of worker nodes that is attached to a HostedCluster resource.

The API version policy generally aligns with the policy for Kubernetes API versioning.

Chapter 2. Getting started with hosted control planes

To get started with hosted control planes for OpenShift Container Platform, you first configure your hosted cluster on the provider that you want to use. Then, you complete a few management tasks.

You can view the procedures by selecting from one of the following providers:

2.1. Bare metal

2.2. OpenShift Virtualization

2.3. Amazon Web Services (AWS)

Important

Hosted control planes on the AWS platform is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

2.4. IBM Z

Important

Hosted control planes on the IBM Z platform is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

2.5. IBM Power

Important

Hosted control planes on the IBM Power platform is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

2.6. Non bare metal agent machines

Important

Hosted control planes clusters using non bare metal agent machines is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Chapter 3. Authentication and authorization for hosted control planes

The OpenShift Container Platform control plane includes a built-in OAuth server. You can obtain OAuth access tokens to authenticate to the OpenShift Container Platform API. After you create your hosted cluster, you can configure OAuth by specifying an identity provider.

3.1. Configuring the OAuth server for a hosted cluster by using the CLI

You can configure the internal OAuth server for your hosted cluster by using an OpenID Connect identity provider (oidc).

You can configure OAuth for the following supported identity providers:

  • oidc
  • htpasswd
  • keystone
  • ldap
  • basic-authentication
  • request-header
  • github
  • gitlab
  • google

Adding any identity provider in the OAuth configuration removes the default kubeadmin user provider.

Prerequisites

  • You created your hosted cluster.

Procedure

  1. Edit the HostedCluster custom resource (CR) on the hosting cluster by running the following command:

    $ oc edit <hosted_cluster_name> -n <hosted_cluster_namespace>
  2. Add the OAuth configuration in the HostedCluster CR by using the following example:

    apiVersion: hypershift.openshift.io/v1alpha1
    kind: HostedCluster
    metadata:
      name: <hosted_cluster_name> 1
      namespace: <hosted_cluster_namespace> 2
    spec:
      configuration:
        oauth:
          identityProviders:
          - openID: 3
              claims:
                email: 4
                  - <email_address>
                name: 5
                  - <display_name>
                preferredUsername: 6
                  - <preferred_username>
              clientID: <client_id> 7
              clientSecret:
                name: <client_id_secret_name> 8
              issuer: https://example.com/identity 9
            mappingMethod: lookup 10
            name: IAM
            type: OpenID
    1
    Specifies your hosted cluster name.
    2
    Specifies your hosted cluster namespace.
    3
    This provider name is prefixed to the value of the identity claim to form an identity name. The provider name is also used to build the redirect URL.
    4
    Defines a list of attributes to use as the email address.
    5
    Defines a list of attributes to use as a display name.
    6
    Defines a list of attributes to use as a preferred user name.
    7
    Defines the ID of a client registered with the OpenID provider. You must allow the client to redirect to the https://oauth-openshift.apps.<cluster_name>.<cluster_domain>/oauth2callback/<idp_provider_name> URL.
    8
    Defines a secret of a client registered with the OpenID provider.
    9
    The Issuer Identifier described in the OpenID spec. You must use https without query or fragment component.
    10
    Defines a mapping method that controls how mappings are established between identities of this provider and User objects.
  3. Save the file to apply the changes.

3.2. Configuring the OAuth server for a hosted cluster by using the web console

You can configure the internal OAuth server for your hosted cluster by using the OpenShift Container Platform web console.

You can configure OAuth for the following supported identity providers:

  • oidc
  • htpasswd
  • keystone
  • ldap
  • basic-authentication
  • request-header
  • github
  • gitlab
  • google

Adding any identity provider in the OAuth configuration removes the default kubeadmin user provider.

Prerequisites

  • You logged in as a user with cluster-admin privileges.
  • You created your hosted cluster.

Procedure

  1. Navigate to HomeAPI Explorer.
  2. Use the Filter by kind box to search for your HostedCluster resource.
  3. Click the HostedCluster resource that you want to edit.
  4. Click the Instances tab.
  5. Click the Options menu kebab next to your hosted cluster name entry and click Edit HostedCluster.
  6. Add the OAuth configuration in the YAML file:

    spec:
      configuration:
        oauth:
          identityProviders:
          - openID: 1
              claims:
                email: 2
                  - <email_address>
                name: 3
                  - <display_name>
                preferredUsername: 4
                  - <preferred_username>
              clientID: <client_id> 5
              clientSecret:
                name: <client_id_secret_name> 6
              issuer: https://example.com/identity 7
            mappingMethod: lookup 8
            name: IAM
            type: OpenID
    1
    This provider name is prefixed to the value of the identity claim to form an identity name. The provider name is also used to build the redirect URL.
    2
    Defines a list of attributes to use as the email address.
    3
    Defines a list of attributes to use as a display name.
    4
    Defines a list of attributes to use as a preferred user name.
    5
    Defines the ID of a client registered with the OpenID provider. You must allow the client to redirect to the https://oauth-openshift.apps.<cluster_name>.<cluster_domain>/oauth2callback/<idp_provider_name> URL.
    6
    Defines a secret of a client registered with the OpenID provider.
    7
    The Issuer Identifier described in the OpenID spec. You must use https without query or fragment component.
    8
    Defines a mapping method that controls how mappings are established between identities of this provider and User objects.
  7. Click Save.

Additional resources

3.3. Assigning components IAM roles by using the CCO in a hosted cluster on AWS

You can assign components IAM roles that provide short-term, limited-privilege security credentials by using the Cloud Credential Operator (CCO) in hosted clusters on Amazon Web Services (AWS). By default, the CCO runs in a hosted control plane.

Note

The CCO supports a manual mode only for hosted clusters on AWS. By default, hosted clusters are configured in a manual mode. The management cluster might use modes other than manual.

3.4. Verifying the CCO installation in a hosted cluster on AWS

You can verify that the Cloud Credential Operator (CCO) is running correctly in your hosted control plane.

Prerequisites

  • You configured the hosted cluster on Amazon Web Services (AWS).

Procedure

  1. Verify that the CCO is configured in a manual mode in your hosted cluster by running the following command:

    $ oc get cloudcredentials <hosted_cluster_name> -n <hosted_cluster_namespace> -o=jsonpath={.spec.credentialsMode}

    Expected output

    Manual

  2. Verify that the value for the serviceAccountIssuer resource is not empty by running the following command:

    $ oc get authentication cluster --kubeconfig <hosted_cluster_name>.kubeconfig -o jsonpath --template '{.spec.serviceAccountIssuer }'

    Example output

    https://aos-hypershift-ci-oidc-29999.s3.us-east-2.amazonaws.com/hypershift-ci-29999

3.5. Enabling Operators to support CCO-based workflows with AWS STS

As an Operator author designing your project to run on Operator Lifecycle Manager (OLM), you can enable your Operator to authenticate against AWS on STS-enabled OpenShift Container Platform clusters by customizing your project to support the Cloud Credential Operator (CCO).

With this method, the Operator is responsible for creating the CredentialsRequest object, which means the Operator requires RBAC permission to create these objects. Then, the Operator must be able to read the resulting Secret object.

Note

By default, pods related to the Operator deployment mount a serviceAccountToken volume so that the service account token can be referenced in the resulting Secret object.

Prerequisities

  • OpenShift Container Platform 4.14 or later
  • Cluster in STS mode
  • OLM-based Operator project

Procedure

  1. Update your Operator project’s ClusterServiceVersion (CSV) object:

    1. Ensure your Operator has RBAC permission to create CredentialsRequests objects:

      Example 3.1. Example clusterPermissions list

      # ...
      install:
        spec:
          clusterPermissions:
          - rules:
            - apiGroups:
              - "cloudcredential.openshift.io"
              resources:
              - credentialsrequests
              verbs:
              - create
              - delete
              - get
              - list
              - patch
              - update
              - watch
    2. Add the following annotation to claim support for this method of CCO-based workflow with AWS STS:

      # ...
      metadata:
       annotations:
         features.operators.openshift.io/token-auth-aws: "true"
  2. Update your Operator project code:

    1. Get the role ARN from the environment variable set on the pod by the Subscription object. For example:

      // Get ENV var
      roleARN := os.Getenv("ROLEARN")
      setupLog.Info("getting role ARN", "role ARN = ", roleARN)
      webIdentityTokenPath := "/var/run/secrets/openshift/serviceaccount/token"
    2. Ensure you have a CredentialsRequest object ready to be patched and applied. For example:

      Example 3.2. Example CredentialsRequest object creation

      import (
         minterv1 "github.com/openshift/cloud-credential-operator/pkg/apis/cloudcredential/v1"
         corev1 "k8s.io/api/core/v1"
         metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
      )
      
      var in = minterv1.AWSProviderSpec{
         StatementEntries: []minterv1.StatementEntry{
            {
               Action: []string{
                  "s3:*",
               },
               Effect:   "Allow",
               Resource: "arn:aws:s3:*:*:*",
            },
         },
      	STSIAMRoleARN: "<role_arn>",
      }
      
      var codec = minterv1.Codec
      var ProviderSpec, _ = codec.EncodeProviderSpec(in.DeepCopyObject())
      
      const (
         name      = "<credential_request_name>"
         namespace = "<namespace_name>"
      )
      
      var CredentialsRequestTemplate = &minterv1.CredentialsRequest{
         ObjectMeta: metav1.ObjectMeta{
             Name:      name,
             Namespace: "openshift-cloud-credential-operator",
         },
         Spec: minterv1.CredentialsRequestSpec{
            ProviderSpec: ProviderSpec,
            SecretRef: corev1.ObjectReference{
               Name:      "<secret_name>",
               Namespace: namespace,
            },
            ServiceAccountNames: []string{
               "<service_account_name>",
            },
            CloudTokenPath:   "",
         },
      }

      Alternatively, if you are starting from a CredentialsRequest object in YAML form (for example, as part of your Operator project code), you can handle it differently:

      Example 3.3. Example CredentialsRequest object creation in YAML form

      // CredentialsRequest is a struct that represents a request for credentials
      type CredentialsRequest struct {
        APIVersion string `yaml:"apiVersion"`
        Kind       string `yaml:"kind"`
        Metadata   struct {
           Name      string `yaml:"name"`
           Namespace string `yaml:"namespace"`
        } `yaml:"metadata"`
        Spec struct {
           SecretRef struct {
              Name      string `yaml:"name"`
              Namespace string `yaml:"namespace"`
           } `yaml:"secretRef"`
           ProviderSpec struct {
              APIVersion     string `yaml:"apiVersion"`
              Kind           string `yaml:"kind"`
              StatementEntries []struct {
                 Effect   string   `yaml:"effect"`
                 Action   []string `yaml:"action"`
                 Resource string   `yaml:"resource"`
              } `yaml:"statementEntries"`
              STSIAMRoleARN   string `yaml:"stsIAMRoleARN"`
           } `yaml:"providerSpec"`
      
           // added new field
            CloudTokenPath   string `yaml:"cloudTokenPath"`
        } `yaml:"spec"`
      }
      
      // ConsumeCredsRequestAddingTokenInfo is a function that takes a YAML filename and two strings as arguments
      // It unmarshals the YAML file to a CredentialsRequest object and adds the token information.
      func ConsumeCredsRequestAddingTokenInfo(fileName, tokenString, tokenPath string) (*CredentialsRequest, error) {
        // open a file containing YAML form of a CredentialsRequest
        file, err := os.Open(fileName)
        if err != nil {
           return nil, err
        }
        defer file.Close()
      
        // create a new CredentialsRequest object
        cr := &CredentialsRequest{}
      
        // decode the yaml file to the object
        decoder := yaml.NewDecoder(file)
        err = decoder.Decode(cr)
        if err != nil {
           return nil, err
        }
      
        // assign the string to the existing field in the object
        cr.Spec.CloudTokenPath = tokenPath
      
        // return the modified object
        return cr, nil
      }
      Note

      Adding a CredentialsRequest object to the Operator bundle is not currently supported.

    3. Add the role ARN and web identity token path to the credentials request and apply it during Operator initialization:

      Example 3.4. Example applying CredentialsRequest object during Operator initialization

      // apply credentialsRequest on install
      credReq := credreq.CredentialsRequestTemplate
      credReq.Spec.CloudTokenPath = webIdentityTokenPath
      
      c := mgr.GetClient()
      if err := c.Create(context.TODO(), credReq); err != nil {
         if !errors.IsAlreadyExists(err) {
            setupLog.Error(err, "unable to create CredRequest")
            os.Exit(1)
         }
      }
    4. Ensure your Operator can wait for a Secret object to show up from the CCO, as shown in the following example, which is called along with the other items you are reconciling in your Operator:

      Example 3.5. Example wait for Secret object

      // WaitForSecret is a function that takes a Kubernetes client, a namespace, and a v1 "k8s.io/api/core/v1" name as arguments
      // It waits until the secret object with the given name exists in the given namespace
      // It returns the secret object or an error if the timeout is exceeded
      func WaitForSecret(client kubernetes.Interface, namespace, name string) (*v1.Secret, error) {
        // set a timeout of 10 minutes
        timeout := time.After(10 * time.Minute) 1
      
        // set a polling interval of 10 seconds
        ticker := time.NewTicker(10 * time.Second)
      
        // loop until the timeout or the secret is found
        for {
           select {
           case <-timeout:
              // timeout is exceeded, return an error
              return nil, fmt.Errorf("timed out waiting for secret %s in namespace %s", name, namespace)
                 // add to this error with a pointer to instructions for following a manual path to a Secret that will work on STS
           case <-ticker.C:
              // polling interval is reached, try to get the secret
              secret, err := client.CoreV1().Secrets(namespace).Get(context.Background(), name, metav1.GetOptions{})
              if err != nil {
                 if errors.IsNotFound(err) {
                    // secret does not exist yet, continue waiting
                    continue
                 } else {
                    // some other error occurred, return it
                    return nil, err
                 }
              } else {
                 // secret is found, return it
                 return secret, nil
              }
           }
        }
      }
      1
      The timeout value is based on an estimate of how fast the CCO might detect an added CredentialsRequest object and generate a Secret object. You might consider lowering the time or creating custom feedback for cluster administrators that could be wondering why the Operator is not yet accessing the cloud resources.
    5. Set up the AWS configuration by reading the secret created by the CCO from the credentials request and creating the AWS config file containing the data from that secret:

      Example 3.6. Example AWS configuration creation

      func SharedCredentialsFileFromSecret(secret *corev1.Secret) (string, error) {
         var data []byte
         switch {
         case len(secret.Data["credentials"]) > 0:
             data = secret.Data["credentials"]
         default:
             return "", errors.New("invalid secret for aws credentials")
         }
      
      
         f, err := ioutil.TempFile("", "aws-shared-credentials")
         if err != nil {
             return "", errors.Wrap(err, "failed to create file for shared credentials")
         }
         defer f.Close()
         if _, err := f.Write(data); err != nil {
             return "", errors.Wrapf(err, "failed to write credentials to %s", f.Name())
         }
         return f.Name(), nil
      }
      Important

      The secret is assumed to exist, but your Operator code should wait and retry when using this secret to give time to the CCO to create the secret.

      Additionally, the wait period should eventually time out and warn users that the OpenShift Container Platform cluster version, and therefore the CCO, might be an earlier version that does not support the CredentialsRequest object workflow with STS detection. In such cases, instruct users that they must add a secret by using another method.

    6. Configure the AWS SDK session, for example:

      Example 3.7. Example AWS SDK session configuration

      sharedCredentialsFile, err := SharedCredentialsFileFromSecret(secret)
      if err != nil {
         // handle error
      }
      options := session.Options{
         SharedConfigState: session.SharedConfigEnable,
         SharedConfigFiles: []string{sharedCredentialsFile},
      }

Chapter 4. Handling a machine configuration for hosted control planes

In a standalone OpenShift Container Platform cluster, a machine config pool manages a set of nodes. You can handle a machine configuration by using the MachineConfigPool custom resource (CR).

In hosted control planes, the MachineConfigPool CR does not exist. A node pool contains a set of compute nodes. You can handle a machine configuration by using node pools.

4.1. Configuring node pools for hosted control planes

On hosted control planes, you can configure node pools by creating a MachineConfig object inside of a config map in the management cluster.

Procedure

  1. To create a MachineConfig object inside of a config map in the management cluster, enter the following information:

    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: <configmap-name>
      namespace: clusters
    data:
      config: |
        apiVersion: machineconfiguration.openshift.io/v1
        kind: MachineConfig
        metadata:
          labels:
            machineconfiguration.openshift.io/role: worker
          name: <machineconfig-name>
        spec:
          config:
            ignition:
              version: 3.2.0
            storage:
              files:
              - contents:
                  source: data:...
                mode: 420
                overwrite: true
                path: ${PATH} 1
    1
    Sets the path on the node where the MachineConfig object is stored.
  2. After you add the object to the config map, you can apply the config map to the node pool as follows:

    $ oc edit nodepool <nodepool_name> --namespace <hosted_cluster_namespace>
    apiVersion: hypershift.openshift.io/v1alpha1
    kind: NodePool
    metadata:
    # ...
      name: nodepool-1
      namespace: clusters
    # ...
    spec:
      config:
      - name: ${configmap-name}
    # ...

4.2. Configuring node tuning in a hosted cluster

To set node-level tuning on the nodes in your hosted cluster, you can use the Node Tuning Operator. In hosted control planes, you can configure node tuning by creating config maps that contain Tuned objects and referencing those config maps in your node pools.

Procedure

  1. Create a config map that contains a valid tuned manifest, and reference the manifest in a node pool. In the following example, a Tuned manifest defines a profile that sets vm.dirty_ratio to 55 on nodes that contain the tuned-1-node-label node label with any value. Save the following ConfigMap manifest in a file named tuned-1.yaml:

        apiVersion: v1
        kind: ConfigMap
        metadata:
          name: tuned-1
          namespace: clusters
        data:
          tuning: |
            apiVersion: tuned.openshift.io/v1
            kind: Tuned
            metadata:
              name: tuned-1
              namespace: openshift-cluster-node-tuning-operator
            spec:
              profile:
              - data: |
                  [main]
                  summary=Custom OpenShift profile
                  include=openshift-node
                  [sysctl]
                  vm.dirty_ratio="55"
                name: tuned-1-profile
              recommend:
              - priority: 20
                profile: tuned-1-profile
    Note

    If you do not add any labels to an entry in the spec.recommend section of the Tuned spec, node-pool-based matching is assumed, so the highest priority profile in the spec.recommend section is applied to nodes in the pool. Although you can achieve more fine-grained node-label-based matching by setting a label value in the Tuned .spec.recommend.match section, node labels will not persist during an upgrade unless you set the .spec.management.upgradeType value of the node pool to InPlace.

  2. Create the ConfigMap object in the management cluster:

    $ oc --kubeconfig="$MGMT_KUBECONFIG" create -f tuned-1.yaml
  3. Reference the ConfigMap object in the spec.tuningConfig field of the node pool, either by editing a node pool or creating one. In this example, assume that you have only one NodePool, named nodepool-1, which contains 2 nodes.

        apiVersion: hypershift.openshift.io/v1alpha1
        kind: NodePool
        metadata:
          ...
          name: nodepool-1
          namespace: clusters
        ...
        spec:
          ...
          tuningConfig:
          - name: tuned-1
        status:
        ...
    Note

    You can reference the same config map in multiple node pools. In hosted control planes, the Node Tuning Operator appends a hash of the node pool name and namespace to the name of the Tuned CRs to distinguish them. Outside of this case, do not create multiple TuneD profiles of the same name in different Tuned CRs for the same hosted cluster.

Verification

Now that you have created the ConfigMap object that contains a Tuned manifest and referenced it in a NodePool, the Node Tuning Operator syncs the Tuned objects into the hosted cluster. You can verify which Tuned objects are defined and which TuneD profiles are applied to each node.

  1. List the Tuned objects in the hosted cluster:

    $ oc --kubeconfig="$HC_KUBECONFIG" get tuned.tuned.openshift.io -n openshift-cluster-node-tuning-operator

    Example output

    NAME       AGE
    default    7m36s
    rendered   7m36s
    tuned-1    65s

  2. List the Profile objects in the hosted cluster:

    $ oc --kubeconfig="$HC_KUBECONFIG" get profile.tuned.openshift.io -n openshift-cluster-node-tuning-operator

    Example output

    NAME                           TUNED            APPLIED   DEGRADED   AGE
    nodepool-1-worker-1            tuned-1-profile  True      False      7m43s
    nodepool-1-worker-2            tuned-1-profile  True      False      7m14s

    Note

    If no custom profiles are created, the openshift-node profile is applied by default.

  3. To confirm that the tuning was applied correctly, start a debug shell on a node and check the sysctl values:

    $ oc --kubeconfig="$HC_KUBECONFIG" debug node/nodepool-1-worker-1 -- chroot /host sysctl vm.dirty_ratio

    Example output

    vm.dirty_ratio = 55

4.3. Deploying the SR-IOV Operator for hosted control planes

Important

Hosted control planes on the AWS platform is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

After you configure and deploy your hosting service cluster, you can create a subscription to the SR-IOV Operator on a hosted cluster. The SR-IOV pod runs on worker machines rather than the control plane.

Prerequisites

You must configure and deploy the hosted cluster on AWS. For more information, see Configuring the hosting cluster on AWS (Technology Preview).

Procedure

  1. Create a namespace and an Operator group:

    apiVersion: v1
    kind: Namespace
    metadata:
      name: openshift-sriov-network-operator
    ---
    apiVersion: operators.coreos.com/v1
    kind: OperatorGroup
    metadata:
      name: sriov-network-operators
      namespace: openshift-sriov-network-operator
    spec:
      targetNamespaces:
      - openshift-sriov-network-operator
  2. Create a subscription to the SR-IOV Operator:

    apiVersion: operators.coreos.com/v1alpha1
    kind: Subscription
    metadata:
      name: sriov-network-operator-subsription
      namespace: openshift-sriov-network-operator
    spec:
      channel: stable
      name: sriov-network-operator
      config:
        nodeSelector:
          node-role.kubernetes.io/worker: ""
      source: s/qe-app-registry/redhat-operators
      sourceNamespace: openshift-marketplace

Verification

  1. To verify that the SR-IOV Operator is ready, run the following command and view the resulting output:

    $ oc get csv -n openshift-sriov-network-operator

    Example output

    NAME                                         DISPLAY                   VERSION               REPLACES                                     PHASE
    sriov-network-operator.4.15.0-202211021237   SR-IOV Network Operator   4.15.0-202211021237   sriov-network-operator.4.15.0-202210290517   Succeeded

  2. To verify that the SR-IOV pods are deployed, run the following command:

    $ oc get pods -n openshift-sriov-network-operator

Chapter 5. Using feature gates in a hosted cluster

You can use feature gates in a hosted cluster to enable features that are not part of the default set of features. You can enable the TechPreviewNoUpgrade feature set by using feature gates in your hosted cluster.

5.1. Enabling feature sets by using feature gates

You can enable the TechPreviewNoUpgrade feature set in a hosted cluster by editing the HostedCluster custom resource (CR) with the OpenShift CLI.

Prerequisites

  • You installed the OpenShift CLI (oc).

Procedure

  1. Open the HostedCluster CR for editing on the hosting cluster by running the following command:

    $ oc edit <hosted_cluster_name> -n <hosted_cluster_namespace>
  2. Define the feature set by entering a value in the featureSet field. For example:

    apiVersion: hypershift.openshift.io/v1beta1
    kind: HostedCluster
    metadata:
      name: <hosted_cluster_name> 1
      namespace: <hosted_cluster_namespace> 2
    spec:
      configuration:
        featureGate:
          featureSet: TechPreviewNoUpgrade 3
    1
    Specifies your hosted cluster name.
    2
    Specifies your hosted cluster namespace.
    3
    This feature set is a subset of the current Technology Preview features.
    Warning

    Enabling the TechPreviewNoUpgrade feature set on your cluster cannot be undone and prevents minor version updates. This feature set allows you to enable these Technology Preview features on test clusters, where you can fully test them. Do not enable this feature set on production clusters.

  3. Save the file to apply the changes.

Verification

  • Verify that the TechPreviewNoUpgrade feature gate is enabled in your hosted cluster by running the following command:

    $ oc get featuregate cluster -o yaml

Chapter 6. Updating hosted control planes

Updates for hosted control planes involve updating the hosted cluster and the node pools. For a cluster to remain fully operational during an update process, you must meet the requirements of the Kubernetes version skew policy while completing the control plane and node updates.

6.1. Requirements to upgrade hosted control planes

The multicluster engine for Kubernetes Operator can manage one or more OpenShift Container Platform clusters. After you create a hosted cluster on OpenShift Container Platform, you must import your hosted cluster in the multicluster engine Operator as a managed cluster. Then, you can use the OpenShift Container Platform cluster as a management cluster.

Consider the following requirements before you start updating hosted control planes:

  • You must use the bare metal platform for an OpenShift Container Platform cluster when using OpenShift Virtualization as a provider.
  • You must use bare metal or OpenShift Virtualization as the cloud platform for the hosted cluster. You can find the platform type of your hosted cluster in the spec.Platform.type specification of the HostedCluster custom resource (CR).

You must upgrade the OpenShift Container Platform cluster, multicluster engine Operator, hosted cluster, and node pools by completing the following tasks:

  1. Upgrade an OpenShift Container Platform cluster to the latest version. For more information, see "Updating a cluster using the web console" or "Updating a cluster using the CLI".
  2. Upgrade the multicluster engine Operator to the latest version. For more information, see "Updating installed Operators".
  3. Upgrade the hosted cluster and node pools from the previous OpenShift Container Platform version to the latest version. For more information, see "Updating a control plane in a hosted cluster" and "Updating node pools in a hosted cluster".

6.2. Setting channels in a hosted cluster

You can see available updates in the HostedCluster.Status field of the HostedCluster custom resource (CR).

The available updates are not fetched from the Cluster Version Operator (CVO) of a hosted cluster. The list of the available updates can be different from the available updates from the following fields of the HostedCluster custom resource (CR):

  • status.version.availableUpdates
  • status.version.conditionalUpdates

The initial HostedCluster CR does not have any information in the status.version.availableUpdates and status.version.conditionalUpdates fields. After you set the spec.channel field to the stable OpenShift Container Platform release version, the HyperShift Operator reconciles the HostedCluster CR and updates the status.version field with the available and conditional updates.

See the following example of the HostedCluster CR that contains the channel configuration:

spec:
  autoscaling: {}
  channel: stable-4.y 1
  clusterID: d6d42268-7dff-4d37-92cf-691bd2d42f41
  configuration: {}
  controllerAvailabilityPolicy: SingleReplica
  dns:
    baseDomain: dev11.red-chesterfield.com
    privateZoneID: Z0180092I0DQRKL55LN0
    publicZoneID: Z00206462VG6ZP0H2QLWK
1
Replace <4.y> with the OpenShift Container Platform release version you specified in spec.release. For example, if you set the spec.release to ocp-release:4.16.4-multi, you must set spec.channel to stable-4.16.

After you configure the channel in the HostedCluster CR, to view the output of the status.version.availableUpdates and status.version.conditionalUpdates fields, run the following command:

$ oc get -n <hosted_cluster_namespace> hostedcluster <hosted_cluster_name> -o yaml

Example output

version:
  availableUpdates:
  - channels:
    - candidate-4.16
    - candidate-4.17
    - eus-4.16
    - fast-4.16
    - stable-4.16
    image: quay.io/openshift-release-dev/ocp-release@sha256:b7517d13514c6308ae16c5fd8108133754eb922cd37403ed27c846c129e67a9a
    url: https://access.redhat.com/errata/RHBA-2024:6401
    version: 4.16.11
  - channels:
    - candidate-4.16
    - candidate-4.17
    - eus-4.16
    - fast-4.16
    - stable-4.16
    image: quay.io/openshift-release-dev/ocp-release@sha256:d08e7c8374142c239a07d7b27d1170eae2b0d9f00ccf074c3f13228a1761c162
    url: https://access.redhat.com/errata/RHSA-2024:6004
    version: 4.16.10
  - channels:
    - candidate-4.16
    - candidate-4.17
    - eus-4.16
    - fast-4.16
    - stable-4.16
    image: quay.io/openshift-release-dev/ocp-release@sha256:6a80ac72a60635a313ae511f0959cc267a21a89c7654f1c15ee16657aafa41a0
    url: https://access.redhat.com/errata/RHBA-2024:5757
    version: 4.16.9
  - channels:
    - candidate-4.16
    - candidate-4.17
    - eus-4.16
    - fast-4.16
    - stable-4.16
    image: quay.io/openshift-release-dev/ocp-release@sha256:ea624ae7d91d3f15094e9e15037244679678bdc89e5a29834b2ddb7e1d9b57e6
    url: https://access.redhat.com/errata/RHSA-2024:5422
    version: 4.16.8
  - channels:
    - candidate-4.16
    - candidate-4.17
    - eus-4.16
    - fast-4.16
    - stable-4.16
    image: quay.io/openshift-release-dev/ocp-release@sha256:e4102eb226130117a0775a83769fe8edb029f0a17b6cbca98a682e3f1225d6b7
    url: https://access.redhat.com/errata/RHSA-2024:4965
    version: 4.16.6
  - channels:
    - candidate-4.16
    - candidate-4.17
    - eus-4.16
    - fast-4.16
    - stable-4.16
    image: quay.io/openshift-release-dev/ocp-release@sha256:f828eda3eaac179e9463ec7b1ed6baeba2cd5bd3f1dd56655796c86260db819b
    url: https://access.redhat.com/errata/RHBA-2024:4855
    version: 4.16.5
  conditionalUpdates:
  - conditions:
    - lastTransitionTime: "2024-09-23T22:33:38Z"
      message: |-
        Could not evaluate exposure to update risk SRIOVFailedToConfigureVF (creating PromQL round-tripper: unable to load specified CA cert /etc/tls/service-ca/service-ca.crt: open /etc/tls/service-ca/service-ca.crt: no such file or directory)
          SRIOVFailedToConfigureVF description: OCP Versions 4.14.34, 4.15.25, 4.16.7 and ALL subsequent versions include kernel datastructure changes which are not compatible with older versions of the SR-IOV operator. Please update SR-IOV operator to versions dated 20240826 or newer before updating OCP.
          SRIOVFailedToConfigureVF URL: https://issues.redhat.com/browse/NHE-1171
      reason: EvaluationFailed
      status: Unknown
      type: Recommended
    release:
      channels:
      - candidate-4.16
      - candidate-4.17
      - eus-4.16
      - fast-4.16
      - stable-4.16
      image: quay.io/openshift-release-dev/ocp-release@sha256:fb321a3f50596b43704dbbed2e51fdefd7a7fd488ee99655d03784d0cd02283f
      url: https://access.redhat.com/errata/RHSA-2024:5107
      version: 4.16.7
    risks:
    - matchingRules:
      - promql:
          promql: |
            group(csv_succeeded{_id="d6d42268-7dff-4d37-92cf-691bd2d42f41", name=~"sriov-network-operator[.].*"})
            or
            0 * group(csv_count{_id="d6d42268-7dff-4d37-92cf-691bd2d42f41"})
        type: PromQL
      message: OCP Versions 4.14.34, 4.15.25, 4.16.7 and ALL subsequent versions
        include kernel datastructure changes which are not compatible with older
        versions of the SR-IOV operator. Please update SR-IOV operator to versions
        dated 20240826 or newer before updating OCP.
      name: SRIOVFailedToConfigureVF
      url: https://issues.redhat.com/browse/NHE-1171

6.3. Updating the OpenShift Container Platform version in a hosted cluster

Hosted control planes enables the decoupling of updates between the control plane and the data plane.

As a cluster service provider or cluster administrator, you can manage the control plane and the data separately.

You can update a control plane by modifying the HostedCluster custom resource (CR) and a node by modifying its NodePool CR. Both the HostedCluster and NodePool CRs specify an OpenShift Container Platform release image in a .release field.

To keep your hosted cluster fully operational during an update process, the control plane and the node updates must follow the Kubernetes version skew policy.

6.3.1. The multicluster engine Operator hub management cluster

The multicluster engine for Kubernetes Operator requires a specific OpenShift Container Platform version for the management cluster to remain in a supported state. You can install the multicluster engine Operator from OperatorHub in the OpenShift Container Platform web console.

See the following support matrices for the multicluster engine Operator versions:

The multicluster engine Operator supports the following OpenShift Container Platform versions:

  • The latest unreleased version
  • The latest released version
  • Two versions before the latest released version

You can also get the multicluster engine Operator version as a part of Red Hat Advanced Cluster Management (RHACM).

6.3.2. Supported OpenShift Container Platform versions in a hosted cluster

When deploying a hosted cluster, the OpenShift Container Platform version of the management cluster does not affect the OpenShift Container Platform version of a hosted cluster.

The HyperShift Operator creates the supported-versions ConfigMap in the hypershift namespace. The supported-versions ConfigMap describes the range of supported OpenShift Container Platform versions that you can deploy.

See the following example of the supported-versions ConfigMap:

apiVersion: v1
data:
    server-version: 2f6cfe21a0861dea3130f3bed0d3ae5553b8c28b
    supported-versions: '{"versions":["4.17","4.16","4.15","4.14"]}'
kind: ConfigMap
metadata:
    creationTimestamp: "2024-06-20T07:12:31Z"
    labels:
        hypershift.openshift.io/supported-versions: "true"
    name: supported-versions
    namespace: hypershift
    resourceVersion: "927029"
    uid: f6336f91-33d3-472d-b747-94abae725f70
Important

To create a hosted cluster, you must use the OpenShift Container Platform version from the support version range. However, the multicluster engine Operator can manage only between n+1 and n-2 OpenShift Container Platform versions, where n defines the current minor version. You can check the multicluster engine Operator support matrix to ensure the hosted clusters managed by the multicluster engine Operator are within the supported OpenShift Container Platform range.

To deploy a higher version of a hosted cluster on OpenShift Container Platform, you must update the multicluster engine Operator to a new minor version release to deploy a new version of the Hypershift Operator. Upgrading the multicluster engine Operator to a new patch, or z-stream, release does not update the HyperShift Operator to the next version.

See the following example output of the hcp version command that shows the supported OpenShift Container Platform versions for OpenShift Container Platform 4.16 in the management cluster:

Client Version: openshift/hypershift: fe67b47fb60e483fe60e4755a02b3be393256343. Latest supported OCP: 4.17.0
Server Version: 05864f61f24a8517731664f8091cedcfc5f9b60d
Server Supports OCP Versions: 4.17, 4.16, 4.15, 4.14

6.4. Updates for the hosted cluster

The spec.release value dictates the version of the control plane. The HostedCluster object transmits the intended spec.release value to the HostedControlPlane.spec.release value and runs the appropriate Control Plane Operator version.

The hosted control plane manages the rollout of the new version of the control plane components along with any OpenShift Container Platform components through the new version of the Cluster Version Operator (CVO).

6.5. Updates for node pools

With node pools, you can configure the software that is running in the nodes by exposing the spec.release and spec.config values. You can start a rolling node pool update in the following ways:

  • Changing the spec.release or spec.config values.
  • Changing any platform-specific field, such as the AWS instance type. The result is a set of new instances with the new type.
  • Changing the cluster configuration, if the change propagates to the node.

Node pools support replace updates and in-place updates. The nodepool.spec.release value dictates the version of any particular node pool. A NodePool object completes a replace or an in-place rolling update according to the .spec.management.upgradeType value.

After you create a node pool, you cannot change the update type. If you want to change the update type, you must create a node pool and delete the other one.

6.5.1. Replace updates for node pools

A replace update creates instances in the new version while it removes old instances from the previous version. This update type is effective in cloud environments where this level of immutability is cost effective.

Replace updates do not preserve any manual changes because the node is entirely re-provisioned.

6.5.2. In place updates for node pools

An in-place update directly updates the operating systems of the instances. This type is suitable for environments where the infrastructure constraints are higher, such as bare metal.

In-place updates can preserve manual changes, but will report errors if you make manual changes to any file system or operating system configuration that the cluster directly manages, such as kubelet certificates.

6.6. Updating node pools in a hosted cluster

You can update your version of OpenShift Container Platform by updating the node pools in your hosted cluster. The node pool version must not surpass the hosted control plane version.

The .spec.release field in the NodePool custom resource (CR) shows the version of a node pool.

Procedure

  • Change the spec.release.image value in the node pool by entering the following command:

    $ oc patch nodepool <node_pool_name> -n <hosted_cluster_namespace> --type=merge -p '{"spec":{"nodeDrainTimeout":"60s","release":{"image":"<openshift_release_image>"}}}' 1 2
    1
    Replace <node_pool_name> and <hosted_cluster_namespace> with your node pool name and hosted cluster namespace, respectively.
    2
    The <openshift_release_image> variable specifies the new OpenShift Container Platform release image that you want to upgrade to, for example, quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64. Replace <4.y.z> with the supported OpenShift Container Platform version.

Verification

  • To verify that the new version was rolled out, check the .status.conditions value in the node pool by running the following command:

    $ oc get -n <hosted_cluster_namespace> nodepool <node_pool_name> -o yaml

    Example output

    status:
     conditions:
     - lastTransitionTime: "2024-05-20T15:00:40Z"
           message: 'Using release image: quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64' 1
           reason: AsExpected
           status: "True"
           type: ValidReleaseImage

    1
    Replace <4.y.z> with the supported OpenShift Container Platform version.

6.7. Updating a control plane in a hosted cluster

On hosted control planes, you can upgrade your version of OpenShift Container Platform by updating the hosted cluster. The .spec.release in the HostedCluster custom resource (CR) shows the version of the control plane. The HostedCluster updates the .spec.release field to the HostedControlPlane.spec.release and runs the appropriate Control Plane Operator version.

The HostedControlPlane resource orchestrates the rollout of the new version of the control plane components along with the OpenShift Container Platform component in the data plane through the new version of the Cluster Version Operator (CVO). The HostedControlPlane includes the following artifacts:

  • CVO
  • Cluster Network Operator (CNO)
  • Cluster Ingress Operator
  • Manifests for the Kube API server, scheduler, and manager
  • Machine approver
  • Autoscaler
  • Infrastructure resources to enable ingress for control plane endpoints such as the Kube API server, ignition, and konnectivity

You can set the .spec.release field in the HostedCluster CR to update the control plane by using the information from the status.version.availableUpdates and status.version.conditionalUpdates fields.

Procedure

  1. Add the hypershift.openshift.io/force-upgrade-to=<openshift_release_image> annotation to the hosted cluster by entering the following command:

    $ oc annotate hostedcluster -n <hosted_cluster_namespace> <hosted_cluster_name> "hypershift.openshift.io/force-upgrade-to=<openshift_release_image>" --overwrite 1 2
    1
    Replace <hosted_cluster_name> and <hosted_cluster_namespace> with your hosted cluster name and hosted cluster namespace, respectively.
    2
    The <openshift_release_image> variable specifies the new OpenShift Container Platform release image that you want to upgrade to, for example, quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64. Replace <4.y.z> with the supported OpenShift Container Platform version.
  2. Change the spec.release.image value in the hosted cluster by entering the following command:

    $ oc patch hostedcluster <hosted_cluster_name> -n <hosted_cluster_namespace> --type=merge -p '{"spec":{"release":{"image":"<openshift_release_image>"}}}'

Verification

  • To verify that the new version was rolled out, check the .status.conditions and .status.version values in the hosted cluster by running the following command:

    $ oc get -n <hosted_cluster_namespace> hostedcluster <hosted_cluster_name> -o yaml

    Example output

    status:
     conditions:
     - lastTransitionTime: "2024-05-20T15:01:01Z"
            message: Payload loaded version="4.y.z" image="quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64" 1
            status: "True"
            type: ClusterVersionReleaseAccepted
    #...
    version:
          availableUpdates: null
          desired:
          image: quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64 2
          version: 4.y.z

    1 2
    Replace <4.y.z> with the supported OpenShift Container Platform version.

6.8. Updating a hosted cluster by using the multicluster engine Operator console

You can update your hosted cluster by using the multicluster engine Operator console.

Important

Before updating a hosted cluster, you must refer to the available and conditional updates of a hosted cluster. Choosing a wrong release version might break the hosted cluster.

Procedure

  1. Select All clusters.
  2. Navigate to InfrastructureClusters to view managed hosted clusters.
  3. Click the Upgrade available link to update the control plane and node pools.

Chapter 7. Hosted control planes Observability

You can gather metrics for hosted control planes by configuring metrics sets. The HyperShift Operator can create or delete monitoring dashboards in the management cluster for each hosted cluster that it manages.

7.1. Configuring metrics sets for hosted control planes

Hosted control planes for Red Hat OpenShift Container Platform creates ServiceMonitor resources in each control plane namespace that allow a Prometheus stack to gather metrics from the control planes. The ServiceMonitor resources use metrics relabelings to define which metrics are included or excluded from a particular component, such as etcd or the Kubernetes API server. The number of metrics that are produced by control planes directly impacts the resource requirements of the monitoring stack that gathers them.

Instead of producing a fixed number of metrics that apply to all situations, you can configure a metrics set that identifies a set of metrics to produce for each control plane. The following metrics sets are supported:

  • Telemetry: These metrics are needed for telemetry. This set is the default set and is the smallest set of metrics.
  • SRE: This set includes the necessary metrics to produce alerts and allow the troubleshooting of control plane components.
  • All: This set includes all of the metrics that are produced by standalone OpenShift Container Platform control plane components.

To configure a metrics set, set the METRICS_SET environment variable in the HyperShift Operator deployment by entering the following command:

$ oc set env -n hypershift deployment/operator METRICS_SET=All

7.1.1. Configuring the SRE metrics set

When you specify the SRE metrics set, the HyperShift Operator looks for a config map named sre-metric-set with a single key: config. The value of the config key must contain a set of RelabelConfigs that are organized by control plane component.

You can specify the following components:

  • etcd
  • kubeAPIServer
  • kubeControllerManager
  • openshiftAPIServer
  • openshiftControllerManager
  • openshiftRouteControllerManager
  • cvo
  • olm
  • catalogOperator
  • registryOperator
  • nodeTuningOperator
  • controlPlaneOperator
  • hostedClusterConfigOperator

A configuration of the SRE metrics set is illustrated in the following example:

kubeAPIServer:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|server).*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_admission_controller_admission_latencies_seconds_.*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_admission_step_admission_latencies_seconds_.*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "scheduler_(e2e_scheduling_latency_microseconds|scheduling_algorithm_predicate_evaluation|scheduling_algorithm_priority_evaluation|scheduling_algorithm_preemption_evaluation|scheduling_algorithm_latency_microseconds|binding_latency_microseconds|scheduling_latency_seconds)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_(request_count|request_latencies|request_latencies_summary|dropped_requests|storage_data_key_generation_latencies_microseconds|storage_transformation_failures_total|storage_transformation_latencies_microseconds|proxy_tunnel_sync_latency_secs)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "docker_(operations|operations_latency_microseconds|operations_errors|operations_timeout)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "reflector_(items_per_list|items_per_watch|list_duration_seconds|lists_total|short_watches_total|watch_duration_seconds|watches_total)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "etcd_(helper_cache_hit_count|helper_cache_miss_count|helper_cache_entry_count|request_cache_get_latencies_summary|request_cache_add_latencies_summary|request_latencies_summary)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "transformation_(transformation_latencies_microseconds|failures_total)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "network_plugin_operations_latency_microseconds|sync_proxy_rules_latency_microseconds|rest_client_request_latency_seconds"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_request_duration_seconds_bucket;(0.15|0.25|0.3|0.35|0.4|0.45|0.6|0.7|0.8|0.9|1.25|1.5|1.75|2.5|3|3.5|4.5|6|7|8|9|15|25|30|50)"
    sourceLabels: ["__name__", "le"]
kubeControllerManager:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|request|server).*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "rest_client_request_latency_seconds_(bucket|count|sum)"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "root_ca_cert_publisher_sync_duration_seconds_(bucket|count|sum)"
    sourceLabels: ["__name__"]
openshiftAPIServer:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|server).*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_admission_controller_admission_latencies_seconds_.*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_admission_step_admission_latencies_seconds_.*"
    sourceLabels: ["__name__"]
  - action:       "drop"
    regex:        "apiserver_request_duration_seconds_bucket;(0.15|0.25|0.3|0.35|0.4|0.45|0.6|0.7|0.8|0.9|1.25|1.5|1.75|2.5|3|3.5|4.5|6|7|8|9|15|25|30|50)"
    sourceLabels: ["__name__", "le"]
openshiftControllerManager:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|request|server).*"
    sourceLabels: ["__name__"]
openshiftRouteControllerManager:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|request|server).*"
    sourceLabels: ["__name__"]
olm:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|server).*"
    sourceLabels: ["__name__"]
catalogOperator:
  - action:       "drop"
    regex:        "etcd_(debugging|disk|server).*"
    sourceLabels: ["__name__"]
cvo:
  - action: drop
    regex: "etcd_(debugging|disk|server).*"
    sourceLabels: ["__name__"]

7.2. Enabling monitoring dashboards in a hosted cluster

To enable monitoring dashboards in a hosted cluster, complete the following steps:

Procedure

  1. Create the hypershift-operator-install-flags config map in the local-cluster namespace, being sure to specify the --monitoring-dashboards flag in the data.installFlagsToAdd section. For example:

    kind: ConfigMap
    apiVersion: v1
    metadata:
      name: hypershift-operator-install-flags
      namespace: local-cluster
    data:
      installFlagsToAdd: "--monitoring-dashboards"
      installFlagsToRemove: ""
  2. Wait a couple of minutes for the HyperShift Operator deployment in the hypershift namespace to be updated to include the following environment variable:

        - name: MONITORING_DASHBOARDS
          value: "1"

    When monitoring dashboards are enabled, for each hosted cluster that the HyperShift Operator manages, the Operator creates a config map named cp-<hosted_cluster_namespace>-<hosted_cluster_name> in the openshift-config-managed namespace, where <hosted_cluster_namespace> is the namespace of the hosted cluster and <hosted_cluster_name> is the name of the hosted cluster. As a result, a new dashboard is added in the administrative console of the management cluster.

  3. To view the dashboard, log in to the management cluster’s console and go to the dashboard for the hosted cluster by clicking Observe → Dashboards.
  4. Optional: To disable a monitoring dashboards in a hosted cluster, remove the --monitoring-dashboards flag from the hypershift-operator-install-flags config map. When you delete a hosted cluster, its corresponding dashboard is also deleted.

7.2.1. Dashboard customization

To generate dashboards for each hosted cluster, the HyperShift Operator uses a template that is stored in the monitoring-dashboard-template config map in the Operator namespace (hypershift). This template contains a set of Grafana panels that contain the metrics for the dashboard. You can edit the content of the config map to customize the dashboards.

When a dashboard is generated, the following strings are replaced with values that correspond to a specific hosted cluster:

Name

Description

__NAME__

The name of the hosted cluster

__NAMESPACE__

The namespace of the hosted cluster

__CONTROL_PLANE_NAMESPACE__

The namespace where the control plane pods of the hosted cluster are placed

__CLUSTER_ID__

The UUID of the hosted cluster, which matches the _id label of the hosted cluster metrics

Chapter 8. High availability for hosted control planes

8.1. Recovering an unhealthy etcd cluster

In a highly available control plane, three etcd pods run as a part of a stateful set in an etcd cluster. To recover an etcd cluster, identify unhealthy etcd pods by checking the etcd cluster health.

8.1.1. Checking the status of an etcd cluster

You can check the status of the etcd cluster health by logging into any etcd pod.

Procedure

  1. Log in to an etcd pod by entering the following command:

    $ oc rsh -n <hosted_control_plane_namespace> -c etcd <etcd_pod_name>
  2. Print the health status of an etcd cluster by entering the following command:

    sh-4.4$ etcdctl endpoint health --cluster -w table

    Example output

    ENDPOINT                                                HEALTH  TOOK        ERROR
    https://etcd-0.etcd-discovery.clusters-hosted.svc:2379  true    9.117698ms

8.1.2. Recovering a failing etcd pod

Each etcd pod of a 3-node cluster has its own persistent volume claim (PVC) to store its data. An etcd pod might fail because of corrupted or missing data. You can recover a failing etcd pod and its PVC.

Procedure

  1. To confirm that the etcd pod is failing, enter the following command:

    $ oc get pods -l app=etcd -n <hosted_control_plane_namespace>

    Example output

    NAME     READY   STATUS             RESTARTS     AGE
    etcd-0   2/2     Running            0            64m
    etcd-1   2/2     Running            0            45m
    etcd-2   1/2     CrashLoopBackOff   1 (5s ago)   64m

    The failing etcd pod might have the CrashLoopBackOff or Error status.

  2. Delete the failing pod and its PVC by entering the following command:

    $ oc delete pvc/<etcd_pvc_name> pod/<etcd_pod_name> --wait=false

Verification

  • Verify that a new etcd pod is up and running by entering the following command:

    $ oc get pods -l app=etcd -n <hosted_control_plane_namespace>

    Example output

    NAME     READY   STATUS    RESTARTS   AGE
    etcd-0   2/2     Running   0          67m
    etcd-1   2/2     Running   0          48m
    etcd-2   2/2     Running   0          2m2s

8.2. Backing up and restoring etcd in an on-premise environment

You can back up and restore etcd on a hosted cluster in an on-premise environment to fix failures.

8.2.1. Backing up and restoring etcd on a hosted cluster in an on-premise environment

By backing up and restoring etcd on a hosted cluster, you can fix failures, such as corrupted or missing data in an etcd member of a three node cluster. If multiple members of the etcd cluster encounter data loss or have a CrashLoopBackOff status, this approach helps prevent an etcd quorum loss.

Important

This procedure requires API downtime.

Prerequisites

  • The oc and jq binaries have been installed.

Procedure

  1. First, set up your environment variables and scale down the API servers:

    1. Set up environment variables for your hosted cluster by entering the following commands, replacing values as necessary:

      $ CLUSTER_NAME=my-cluster
      $ HOSTED_CLUSTER_NAMESPACE=clusters
      $ CONTROL_PLANE_NAMESPACE="${HOSTED_CLUSTER_NAMESPACE}-${CLUSTER_NAME}"
    2. Pause reconciliation of the hosted cluster by entering the following command, replacing values as necessary:

      $ oc patch -n ${HOSTED_CLUSTER_NAMESPACE} hostedclusters/${CLUSTER_NAME} -p '{"spec":{"pausedUntil":"true"}}' --type=merge
    3. Scale down the API servers by entering the following commands:

      1. Scale down the kube-apiserver:

        $ oc scale -n ${CONTROL_PLANE_NAMESPACE} deployment/kube-apiserver --replicas=0
      2. Scale down the openshift-apiserver:

        $ oc scale -n ${CONTROL_PLANE_NAMESPACE} deployment/openshift-apiserver --replicas=0
      3. Scale down the openshift-oauth-apiserver:

        $ oc scale -n ${CONTROL_PLANE_NAMESPACE} deployment/openshift-oauth-apiserver --replicas=0
  2. Next, take a snapshot of etcd by using one of the following methods:

    1. Use a previously backed-up snapshot of etcd.
    2. If you have an available etcd pod, take a snapshot from the active etcd pod by completing the following steps:

      1. List etcd pods by entering the following command:

        $ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd
      2. Take a snapshot of the pod database and save it locally to your machine by entering the following commands:

        $ ETCD_POD=etcd-0
        $ oc exec -n ${CONTROL_PLANE_NAMESPACE} -c etcd -t ${ETCD_POD} -- env ETCDCTL_API=3 /usr/bin/etcdctl \
        --cacert /etc/etcd/tls/etcd-ca/ca.crt \
        --cert /etc/etcd/tls/client/etcd-client.crt \
        --key /etc/etcd/tls/client/etcd-client.key \
        --endpoints=https://localhost:2379 \
        snapshot save /var/lib/snapshot.db
      3. Verify that the snapshot is successful by entering the following command:

        $ oc exec -n ${CONTROL_PLANE_NAMESPACE} -c etcd -t ${ETCD_POD} -- env ETCDCTL_API=3 /usr/bin/etcdctl -w table snapshot status /var/lib/snapshot.db
    3. Make a local copy of the snapshot by entering the following command:

      $ oc cp -c etcd ${CONTROL_PLANE_NAMESPACE}/${ETCD_POD}:/var/lib/snapshot.db /tmp/etcd.snapshot.db
      1. Make a copy of the snapshot database from etcd persistent storage:

        1. List etcd pods by entering the following command:

          $ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd
        2. Find a pod that is running and set its name as the value of ETCD_POD: ETCD_POD=etcd-0, and then copy its snapshot database by entering the following command:

          $ oc cp -c etcd ${CONTROL_PLANE_NAMESPACE}/${ETCD_POD}:/var/lib/data/member/snap/db /tmp/etcd.snapshot.db
  3. Next, scale down the etcd statefulset by entering the following command:

    $ oc scale -n ${CONTROL_PLANE_NAMESPACE} statefulset/etcd --replicas=0
    1. Delete volumes for second and third members by entering the following command:

      $ oc delete -n ${CONTROL_PLANE_NAMESPACE} pvc/data-etcd-1 pvc/data-etcd-2
    2. Create a pod to access the first etcd member’s data:

      1. Get the etcd image by entering the following command:

        $ ETCD_IMAGE=$(oc get -n ${CONTROL_PLANE_NAMESPACE} statefulset/etcd -o jsonpath='{ .spec.template.spec.containers[0].image }')
      2. Create a pod that allows access to etcd data:

        $ cat << EOF | oc apply -n ${CONTROL_PLANE_NAMESPACE} -f -
        apiVersion: apps/v1
        kind: Deployment
        metadata:
          name: etcd-data
        spec:
          replicas: 1
          selector:
            matchLabels:
              app: etcd-data
          template:
            metadata:
              labels:
                app: etcd-data
            spec:
              containers:
              - name: access
                image: $ETCD_IMAGE
                volumeMounts:
                - name: data
                  mountPath: /var/lib
                command:
                - /usr/bin/bash
                args:
                - -c
                - |-
                  while true; do
                    sleep 1000
                  done
              volumes:
              - name: data
                persistentVolumeClaim:
                  claimName: data-etcd-0
        EOF
      3. Check the status of the etcd-data pod and wait for it to be running by entering the following command:

        $ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd-data
      4. Get the name of the etcd-data pod by entering the following command:

        $ DATA_POD=$(oc get -n ${CONTROL_PLANE_NAMESPACE} pods --no-headers -l app=etcd-data -o name | cut -d/ -f2)
    3. Copy an etcd snapshot into the pod by entering the following command:

      $ oc cp /tmp/etcd.snapshot.db ${CONTROL_PLANE_NAMESPACE}/${DATA_POD}:/var/lib/restored.snap.db
    4. Remove old data from the etcd-data pod by entering the following commands:

      $ oc exec -n ${CONTROL_PLANE_NAMESPACE} ${DATA_POD} -- rm -rf /var/lib/data
      $ oc exec -n ${CONTROL_PLANE_NAMESPACE} ${DATA_POD} -- mkdir -p /var/lib/data
    5. Restore the etcd snapshot by entering the following command:

      $ oc exec -n ${CONTROL_PLANE_NAMESPACE} ${DATA_POD} -- etcdutl snapshot restore /var/lib/restored.snap.db \
           --data-dir=/var/lib/data --skip-hash-check \
           --name etcd-0 \
           --initial-cluster-token=etcd-cluster \
           --initial-cluster etcd-0=https://etcd-0.etcd-discovery.${CONTROL_PLANE_NAMESPACE}.svc:2380,etcd-1=https://etcd-1.etcd-discovery.${CONTROL_PLANE_NAMESPACE}.svc:2380,etcd-2=https://etcd-2.etcd-discovery.${CONTROL_PLANE_NAMESPACE}.svc:2380 \
           --initial-advertise-peer-urls https://etcd-0.etcd-discovery.${CONTROL_PLANE_NAMESPACE}.svc:2380
    6. Remove the temporary etcd snapshot from the pod by entering the following command:

      $ oc exec -n ${CONTROL_PLANE_NAMESPACE} ${DATA_POD} -- rm /var/lib/restored.snap.db
    7. Delete data access deployment by entering the following command:

      $ oc delete -n ${CONTROL_PLANE_NAMESPACE} deployment/etcd-data
    8. Scale up the etcd cluster by entering the following command:

      $ oc scale -n ${CONTROL_PLANE_NAMESPACE} statefulset/etcd --replicas=3
    9. Wait for the etcd member pods to return and report as available by entering the following command:

      $ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd -w
    10. Scale up all etcd-writer deployments by entering the following command:

      $ oc scale deployment -n ${CONTROL_PLANE_NAMESPACE} --replicas=3 kube-apiserver openshift-apiserver openshift-oauth-apiserver
  4. Restore reconciliation of the hosted cluster by entering the following command:

    $ oc patch -n ${CLUSTER_NAMESPACE} hostedclusters/${CLUSTER_NAME} -p '{"spec":{"pausedUntil":""}}' --type=merge

8.3. Backing up and restoring etcd on AWS

You can back up and restore etcd on a hosted cluster on Amazon Web Services (AWS) to fix failures.

Important

Hosted control planes on the AWS platform is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

8.3.1. Taking a snapshot of etcd for a hosted cluster

To back up etcd for a hosted cluster, you must take a snapshot of etcd. Later, you can restore etcd by using the snapshot.

Important

This procedure requires API downtime.

Procedure

  1. Pause reconciliation of the hosted cluster by entering the following command:

    $ oc patch -n clusters hostedclusters/<hosted_cluster_name> -p '{"spec":{"pausedUntil":"true"}}' --type=merge
  2. Stop all etcd-writer deployments by entering the following command:

    $ oc scale deployment -n <hosted_cluster_namespace> --replicas=0 kube-apiserver openshift-apiserver openshift-oauth-apiserver
  3. To take an etcd snapshot, use the exec command in each etcd container by entering the following command:

    $ oc exec -it <etcd_pod_name> -n <hosted_cluster_namespace> -- env ETCDCTL_API=3 /usr/bin/etcdctl --cacert /etc/etcd/tls/etcd-ca/ca.crt --cert /etc/etcd/tls/client/etcd-client.crt --key /etc/etcd/tls/client/etcd-client.key --endpoints=localhost:2379 snapshot save /var/lib/data/snapshot.db
  4. To check the snapshot status, use the exec command in each etcd container by running the following command:

    $ oc exec -it <etcd_pod_name> -n <hosted_cluster_namespace> -- env ETCDCTL_API=3 /usr/bin/etcdctl -w table snapshot status /var/lib/data/snapshot.db
  5. Copy the snapshot data to a location where you can retrieve it later, such as an S3 bucket. See the following example.

    Note

    The following example uses signature version 2. If you are in a region that supports signature version 4, such as the us-east-2 region, use signature version 4. Otherwise, when copying the snapshot to an S3 bucket, the upload fails.

    Example

    BUCKET_NAME=somebucket
    FILEPATH="/${BUCKET_NAME}/${CLUSTER_NAME}-snapshot.db"
    CONTENT_TYPE="application/x-compressed-tar"
    DATE_VALUE=`date -R`
    SIGNATURE_STRING="PUT\n\n${CONTENT_TYPE}\n${DATE_VALUE}\n${FILEPATH}"
    ACCESS_KEY=accesskey
    SECRET_KEY=secret
    SIGNATURE_HASH=`echo -en ${SIGNATURE_STRING} | openssl sha1 -hmac ${SECRET_KEY} -binary | base64`
    
    oc exec -it etcd-0 -n ${HOSTED_CLUSTER_NAMESPACE} -- curl -X PUT -T "/var/lib/data/snapshot.db" \
      -H "Host: ${BUCKET_NAME}.s3.amazonaws.com" \
      -H "Date: ${DATE_VALUE}" \
      -H "Content-Type: ${CONTENT_TYPE}" \
      -H "Authorization: AWS ${ACCESS_KEY}:${SIGNATURE_HASH}" \
      https://${BUCKET_NAME}.s3.amazonaws.com/${CLUSTER_NAME}-snapshot.db

  6. To restore the snapshot on a new cluster later, save the encryption secret that the hosted cluster references.

    1. Get the secret encryption key by entering the following command:

      $ oc get hostedcluster <hosted_cluster_name> -o=jsonpath='{.spec.secretEncryption.aescbc}'
      {"activeKey":{"name":"<hosted_cluster_name>-etcd-encryption-key"}}
    2. Save the secret encryption key by entering the following command:

      $ oc get secret <hosted_cluster_name>-etcd-encryption-key -o=jsonpath='{.data.key}'

      You can decrypt this key when restoring a snapshot on a new cluster.

Next steps

Restore the etcd snapshot.

8.3.2. Restoring an etcd snapshot on a hosted cluster

If you have a snapshot of etcd from your hosted cluster, you can restore it. Currently, you can restore an etcd snapshot only during cluster creation.

To restore an etcd snapshot, you modify the output from the create cluster --render command and define a restoreSnapshotURL value in the etcd section of the HostedCluster specification.

Note

The --render flag in the hcp create command does not render the secrets. To render the secrets, you must use both the --render and the --render-sensitive flags in the hcp create command.

Prerequisites

You took an etcd snapshot on a hosted cluster.

Procedure

  1. On the aws command-line interface (CLI), create a pre-signed URL so that you can download your etcd snapshot from S3 without passing credentials to the etcd deployment:

    ETCD_SNAPSHOT=${ETCD_SNAPSHOT:-"s3://${BUCKET_NAME}/${CLUSTER_NAME}-snapshot.db"}
    ETCD_SNAPSHOT_URL=$(aws s3 presign ${ETCD_SNAPSHOT})
  2. Modify the HostedCluster specification to refer to the URL:

    spec:
      etcd:
        managed:
          storage:
            persistentVolume:
              size: 4Gi
            type: PersistentVolume
            restoreSnapshotURL:
            - "${ETCD_SNAPSHOT_URL}"
        managementType: Managed
  3. Ensure that the secret that you referenced from the spec.secretEncryption.aescbc value contains the same AES key that you saved in the previous steps.

8.4. Disaster recovery for a hosted cluster in AWS

You can recover a hosted cluster to the same region within Amazon Web Services (AWS). For example, you need disaster recovery when the upgrade of a management cluster fails and the hosted cluster is in a read-only state.

Important

Hosted control planes is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

The disaster recovery process involves the following steps:

  1. Backing up the hosted cluster on the source management cluster
  2. Restoring the hosted cluster on a destination management cluster
  3. Deleting the hosted cluster from the source management cluster

Your workloads remain running during the process. The Cluster API might be unavailable for a period, but that does not affect the services that are running on the worker nodes.

Important

Both the source management cluster and the destination management cluster must have the --external-dns flags to maintain the API server URL. That way, the server URL ends with https://api-sample-hosted.sample-hosted.aws.openshift.com. See the following example:

Example: External DNS flags

--external-dns-provider=aws \
--external-dns-credentials=<path_to_aws_credentials_file> \
--external-dns-domain-filter=<basedomain>

If you do not include the --external-dns flags to maintain the API server URL, you cannot migrate the hosted cluster.

8.4.1. Overview of the backup and restore process

The backup and restore process works as follows:

  1. On management cluster 1, which you can think of as the source management cluster, the control plane and workers interact by using the external DNS API. The external DNS API is accessible, and a load balancer sits between the management clusters.

    Diagram that shows the workers accessing the external DNS API and the external DNS API pointing to the control plane through a load balancer
  2. You take a snapshot of the hosted cluster, which includes etcd, the control plane, and the worker nodes. During this process, the worker nodes continue to try to access the external DNS API even if it is not accessible, the workloads are running, the control plane is saved in a local manifest file, and etcd is backed up to an S3 bucket. The data plane is active and the control plane is paused.

    298 OpenShift Backup Restore 0123 01
  3. On management cluster 2, which you can think of as the destination management cluster, you restore etcd from the S3 bucket and restore the control plane from the local manifest file. During this process, the external DNS API is stopped, the hosted cluster API becomes inaccessible, and any workers that use the API are unable to update their manifest files, but the workloads are still running.

    298 OpenShift Backup Restore 0123 02
  4. The external DNS API is accessible again, and the worker nodes use it to move to management cluster 2. The external DNS API can access the load balancer that points to the control plane.

    298 OpenShift Backup Restore 0123 03
  5. On management cluster 2, the control plane and worker nodes interact by using the external DNS API. The resources are deleted from management cluster 1, except for the S3 backup of etcd. If you try to set up the hosted cluster again on mangagement cluster 1, it will not work.

    298 OpenShift Backup Restore 0123 04

8.4.2. Backing up a hosted cluster

To recover your hosted cluster in your target management cluster, you first need to back up all of the relevant data.

Procedure

  1. Create a configmap file to declare the source management cluster by entering this command:

    $ oc create configmap mgmt-parent-cluster -n default --from-literal=from=${MGMT_CLUSTER_NAME}
  2. Shut down the reconciliation in the hosted cluster and in the node pools by entering these commands:

    $ PAUSED_UNTIL="true"
    $ oc patch -n ${HC_CLUSTER_NS} hostedclusters/${HC_CLUSTER_NAME} -p '{"spec":{"pausedUntil":"'${PAUSED_UNTIL}'"}}' --type=merge
    $ oc scale deployment -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --replicas=0 kube-apiserver openshift-apiserver openshift-oauth-apiserver control-plane-operator
    $ PAUSED_UNTIL="true"
    $ oc patch -n ${HC_CLUSTER_NS} hostedclusters/${HC_CLUSTER_NAME} -p '{"spec":{"pausedUntil":"'${PAUSED_UNTIL}'"}}' --type=merge
    $ oc patch -n ${HC_CLUSTER_NS} nodepools/${NODEPOOLS} -p '{"spec":{"pausedUntil":"'${PAUSED_UNTIL}'"}}' --type=merge
    $ oc scale deployment -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --replicas=0 kube-apiserver openshift-apiserver openshift-oauth-apiserver control-plane-operator
  3. Back up etcd and upload the data to an S3 bucket by running this bash script:

    Tip

    Wrap this script in a function and call it from the main function.

    # ETCD Backup
    ETCD_PODS="etcd-0"
    if [ "${CONTROL_PLANE_AVAILABILITY_POLICY}" = "HighlyAvailable" ]; then
      ETCD_PODS="etcd-0 etcd-1 etcd-2"
    fi
    
    for POD in ${ETCD_PODS}; do
      # Create an etcd snapshot
      oc exec -it ${POD} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -- env ETCDCTL_API=3 /usr/bin/etcdctl --cacert /etc/etcd/tls/client/etcd-client-ca.crt --cert /etc/etcd/tls/client/etcd-client.crt --key /etc/etcd/tls/client/etcd-client.key --endpoints=localhost:2379 snapshot save /var/lib/data/snapshot.db
      oc exec -it ${POD} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -- env ETCDCTL_API=3 /usr/bin/etcdctl -w table snapshot status /var/lib/data/snapshot.db
    
      FILEPATH="/${BUCKET_NAME}/${HC_CLUSTER_NAME}-${POD}-snapshot.db"
      CONTENT_TYPE="application/x-compressed-tar"
      DATE_VALUE=`date -R`
      SIGNATURE_STRING="PUT\n\n${CONTENT_TYPE}\n${DATE_VALUE}\n${FILEPATH}"
    
      set +x
      ACCESS_KEY=$(grep aws_access_key_id ${AWS_CREDS} | head -n1 | cut -d= -f2 | sed "s/ //g")
      SECRET_KEY=$(grep aws_secret_access_key ${AWS_CREDS} | head -n1 | cut -d= -f2 | sed "s/ //g")
      SIGNATURE_HASH=$(echo -en ${SIGNATURE_STRING} | openssl sha1 -hmac "${SECRET_KEY}" -binary | base64)
      set -x
    
      # FIXME: this is pushing to the OIDC bucket
      oc exec -it etcd-0 -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -- curl -X PUT -T "/var/lib/data/snapshot.db" \
        -H "Host: ${BUCKET_NAME}.s3.amazonaws.com" \
        -H "Date: ${DATE_VALUE}" \
        -H "Content-Type: ${CONTENT_TYPE}" \
        -H "Authorization: AWS ${ACCESS_KEY}:${SIGNATURE_HASH}" \
        https://${BUCKET_NAME}.s3.amazonaws.com/${HC_CLUSTER_NAME}-${POD}-snapshot.db
    done

    For more information about backing up etcd, see "Backing up and restoring etcd on a hosted cluster".

  4. Back up Kubernetes and OpenShift Container Platform objects by entering the following commands. You need to back up the following objects:

    • HostedCluster and NodePool objects from the HostedCluster namespace
    • HostedCluster secrets from the HostedCluster namespace
    • HostedControlPlane from the Hosted Control Plane namespace
    • Cluster from the Hosted Control Plane namespace
    • AWSCluster, AWSMachineTemplate, and AWSMachine from the Hosted Control Plane namespace
    • MachineDeployments, MachineSets, and Machines from the Hosted Control Plane namespace
    • ControlPlane secrets from the Hosted Control Plane namespace

      $ mkdir -p ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS} ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}
      $ chmod 700 ${BACKUP_DIR}/namespaces/
      
      # HostedCluster
      $ echo "Backing Up HostedCluster Objects:"
      $ oc get hc ${HC_CLUSTER_NAME} -n ${HC_CLUSTER_NS} -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/hc-${HC_CLUSTER_NAME}.yaml
      $ echo "--> HostedCluster"
      $ sed -i '' -e '/^status:$/,$d' ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/hc-${HC_CLUSTER_NAME}.yaml
      
      # NodePool
      $ oc get np ${NODEPOOLS} -n ${HC_CLUSTER_NS} -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/np-${NODEPOOLS}.yaml
      $ echo "--> NodePool"
      $ sed -i '' -e '/^status:$/,$ d' ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/np-${NODEPOOLS}.yaml
      
      # Secrets in the HC Namespace
      $ echo "--> HostedCluster Secrets:"
      for s in $(oc get secret -n ${HC_CLUSTER_NS} | grep "^${HC_CLUSTER_NAME}" | awk '{print $1}'); do
          oc get secret -n ${HC_CLUSTER_NS} $s -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/secret-${s}.yaml
      done
      
      # Secrets in the HC Control Plane Namespace
      $ echo "--> HostedCluster ControlPlane Secrets:"
      for s in $(oc get secret -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} | egrep -v "docker|service-account-token|oauth-openshift|NAME|token-${HC_CLUSTER_NAME}" | awk '{print $1}'); do
          oc get secret -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} $s -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/secret-${s}.yaml
      done
      
      # Hosted Control Plane
      $ echo "--> HostedControlPlane:"
      $ oc get hcp ${HC_CLUSTER_NAME} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/hcp-${HC_CLUSTER_NAME}.yaml
      
      # Cluster
      $ echo "--> Cluster:"
      $ CL_NAME=$(oc get hcp ${HC_CLUSTER_NAME} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o jsonpath={.metadata.labels.\*} | grep ${HC_CLUSTER_NAME})
      $ oc get cluster ${CL_NAME} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/cl-${HC_CLUSTER_NAME}.yaml
      
      # AWS Cluster
      $ echo "--> AWS Cluster:"
      $ oc get awscluster ${HC_CLUSTER_NAME} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/awscl-${HC_CLUSTER_NAME}.yaml
      
      # AWS MachineTemplate
      $ echo "--> AWS Machine Template:"
      $ oc get awsmachinetemplate ${NODEPOOLS} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/awsmt-${HC_CLUSTER_NAME}.yaml
      
      # AWS Machines
      $ echo "--> AWS Machine:"
      $ CL_NAME=$(oc get hcp ${HC_CLUSTER_NAME} -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o jsonpath={.metadata.labels.\*} | grep ${HC_CLUSTER_NAME})
      for s in $(oc get awsmachines -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --no-headers | grep ${CL_NAME} | cut -f1 -d\ ); do
          oc get -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} awsmachines $s -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/awsm-${s}.yaml
      done
      
      # MachineDeployments
      $ echo "--> HostedCluster MachineDeployments:"
      for s in $(oc get machinedeployment -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o name); do
          mdp_name=$(echo ${s} | cut -f 2 -d /)
          oc get -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} $s -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/machinedeployment-${mdp_name}.yaml
      done
      
      # MachineSets
      $ echo "--> HostedCluster MachineSets:"
      for s in $(oc get machineset -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o name); do
          ms_name=$(echo ${s} | cut -f 2 -d /)
          oc get -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} $s -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/machineset-${ms_name}.yaml
      done
      
      # Machines
      $ echo "--> HostedCluster Machine:"
      for s in $(oc get machine -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o name); do
          m_name=$(echo ${s} | cut -f 2 -d /)
          oc get -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} $s -o yaml > ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/machine-${m_name}.yaml
      done
  5. Clean up the ControlPlane routes by entering this command:

    $ oc delete routes -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --all

    By entering that command, you enable the ExternalDNS Operator to delete the Route53 entries.

  6. Verify that the Route53 entries are clean by running this script:

    function clean_routes() {
    
        if [[ -z "${1}" ]];then
            echo "Give me the NS where to clean the routes"
            exit 1
        fi
    
        # Constants
        if [[ -z "${2}" ]];then
            echo "Give me the Route53 zone ID"
            exit 1
        fi
    
        ZONE_ID=${2}
        ROUTES=10
        timeout=40
        count=0
    
        # This allows us to remove the ownership in the AWS for the API route
        oc delete route -n ${1} --all
    
        while [ ${ROUTES} -gt 2 ]
        do
            echo "Waiting for ExternalDNS Operator to clean the DNS Records in AWS Route53 where the zone id is: ${ZONE_ID}..."
            echo "Try: (${count}/${timeout})"
            sleep 10
            if [[ $count -eq timeout ]];then
                echo "Timeout waiting for cleaning the Route53 DNS records"
                exit 1
            fi
            count=$((count+1))
            ROUTES=$(aws route53 list-resource-record-sets --hosted-zone-id ${ZONE_ID} --max-items 10000 --output json | grep -c ${EXTERNAL_DNS_DOMAIN})
        done
    }
    
    # SAMPLE: clean_routes "<HC ControlPlane Namespace>" "<AWS_ZONE_ID>"
    clean_routes "${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}" "${AWS_ZONE_ID}"

Verification

Check all of the OpenShift Container Platform objects and the S3 bucket to verify that everything looks as expected.

Next steps

Restore your hosted cluster.

8.4.3. Restoring a hosted cluster

Gather all of the objects that you backed up and restore them in your destination management cluster.

Prerequisites

You backed up the data from your source management cluster.

Tip

Ensure that the kubeconfig file of the destination management cluster is placed as it is set in the KUBECONFIG variable or, if you use the script, in the MGMT2_KUBECONFIG variable. Use export KUBECONFIG=<Kubeconfig FilePath> or, if you use the script, use export KUBECONFIG=${MGMT2_KUBECONFIG}.

Procedure

  1. Verify that the new management cluster does not contain any namespaces from the cluster that you are restoring by entering these commands:

    # Just in case
    $ export KUBECONFIG=${MGMT2_KUBECONFIG}
    $ BACKUP_DIR=${HC_CLUSTER_DIR}/backup
    
    # Namespace deletion in the destination Management cluster
    $ oc delete ns ${HC_CLUSTER_NS} || true
    $ oc delete ns ${HC_CLUSTER_NS}-{HC_CLUSTER_NAME} || true
  2. Re-create the deleted namespaces by entering these commands:

    # Namespace creation
    $ oc new-project ${HC_CLUSTER_NS}
    $ oc new-project ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}
  3. Restore the secrets in the HC namespace by entering this command:

    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/secret-*
  4. Restore the objects in the HostedCluster control plane namespace by entering these commands:

    # Secrets
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/secret-*
    
    # Cluster
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/hcp-*
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/cl-*
  5. If you are recovering the nodes and the node pool to reuse AWS instances, restore the objects in the HC control plane namespace by entering these commands:

    # AWS
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/awscl-*
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/awsmt-*
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/awsm-*
    
    # Machines
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/machinedeployment-*
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/machineset-*
    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}/machine-*
  6. Restore the etcd data and the hosted cluster by running this bash script:

    ETCD_PODS="etcd-0"
    if [ "${CONTROL_PLANE_AVAILABILITY_POLICY}" = "HighlyAvailable" ]; then
      ETCD_PODS="etcd-0 etcd-1 etcd-2"
    fi
    
    HC_RESTORE_FILE=${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/hc-${HC_CLUSTER_NAME}-restore.yaml
    HC_BACKUP_FILE=${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/hc-${HC_CLUSTER_NAME}.yaml
    HC_NEW_FILE=${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/hc-${HC_CLUSTER_NAME}-new.yaml
    cat ${HC_BACKUP_FILE} > ${HC_NEW_FILE}
    cat > ${HC_RESTORE_FILE} <<EOF
        restoreSnapshotURL:
    EOF
    
    for POD in ${ETCD_PODS}; do
      # Create a pre-signed URL for the etcd snapshot
      ETCD_SNAPSHOT="s3://${BUCKET_NAME}/${HC_CLUSTER_NAME}-${POD}-snapshot.db"
      ETCD_SNAPSHOT_URL=$(AWS_DEFAULT_REGION=${MGMT2_REGION} aws s3 presign ${ETCD_SNAPSHOT})
    
      # FIXME no CLI support for restoreSnapshotURL yet
      cat >> ${HC_RESTORE_FILE} <<EOF
        - "${ETCD_SNAPSHOT_URL}"
    EOF
    done
    
    cat ${HC_RESTORE_FILE}
    
    if ! grep ${HC_CLUSTER_NAME}-snapshot.db ${HC_NEW_FILE}; then
      sed -i '' -e "/type: PersistentVolume/r ${HC_RESTORE_FILE}" ${HC_NEW_FILE}
      sed -i '' -e '/pausedUntil:/d' ${HC_NEW_FILE}
    fi
    
    HC=$(oc get hc -n ${HC_CLUSTER_NS} ${HC_CLUSTER_NAME} -o name || true)
    if [[ ${HC} == "" ]];then
        echo "Deploying HC Cluster: ${HC_CLUSTER_NAME} in ${HC_CLUSTER_NS} namespace"
        oc apply -f ${HC_NEW_FILE}
    else
        echo "HC Cluster ${HC_CLUSTER_NAME} already exists, avoiding step"
    fi
  7. If you are recovering the nodes and the node pool to reuse AWS instances, restore the node pool by entering this command:

    $ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/np-*

Verification

  • To verify that the nodes are fully restored, use this function:

    timeout=40
    count=0
    NODE_STATUS=$(oc get nodes --kubeconfig=${HC_KUBECONFIG} | grep -v NotReady | grep -c "worker") || NODE_STATUS=0
    
    while [ ${NODE_POOL_REPLICAS} != ${NODE_STATUS} ]
    do
        echo "Waiting for Nodes to be Ready in the destination MGMT Cluster: ${MGMT2_CLUSTER_NAME}"
        echo "Try: (${count}/${timeout})"
        sleep 30
        if [[ $count -eq timeout ]];then
            echo "Timeout waiting for Nodes in the destination MGMT Cluster"
            exit 1
        fi
        count=$((count+1))
        NODE_STATUS=$(oc get nodes --kubeconfig=${HC_KUBECONFIG} | grep -v NotReady | grep -c "worker") || NODE_STATUS=0
    done

Next steps

Shut down and delete your cluster.

8.4.4. Deleting a hosted cluster from your source management cluster

After you back up your hosted cluster and restore it to your destination management cluster, you shut down and delete the hosted cluster on your source management cluster.

Prerequisites

You backed up your data and restored it to your source management cluster.

Tip

Ensure that the kubeconfig file of the destination management cluster is placed as it is set in the KUBECONFIG variable or, if you use the script, in the MGMT_KUBECONFIG variable. Use export KUBECONFIG=<Kubeconfig FilePath> or, if you use the script, use export KUBECONFIG=${MGMT_KUBECONFIG}.

Procedure

  1. Scale the deployment and statefulset objects by entering these commands:

    Important

    Do not scale the stateful set if the value of its spec.persistentVolumeClaimRetentionPolicy.whenScaled field is set to Delete, because this could lead to a loss of data.

    As a workaround, update the value of the spec.persistentVolumeClaimRetentionPolicy.whenScaled field to Retain. Ensure that no controllers exist that reconcile the stateful set and would return the value back to Delete, which could lead to a loss of data.

    # Just in case
    $ export KUBECONFIG=${MGMT_KUBECONFIG}
    
    # Scale down deployments
    $ oc scale deployment -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --replicas=0 --all
    $ oc scale statefulset.apps -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --replicas=0 --all
    $ sleep 15
  2. Delete the NodePool objects by entering these commands:

    NODEPOOLS=$(oc get nodepools -n ${HC_CLUSTER_NS} -o=jsonpath='{.items[?(@.spec.clusterName=="'${HC_CLUSTER_NAME}'")].metadata.name}')
    if [[ ! -z "${NODEPOOLS}" ]];then
        oc patch -n "${HC_CLUSTER_NS}" nodepool ${NODEPOOLS} --type=json --patch='[ { "op":"remove", "path": "/metadata/finalizers" }]'
        oc delete np -n ${HC_CLUSTER_NS} ${NODEPOOLS}
    fi
  3. Delete the machine and machineset objects by entering these commands:

    # Machines
    for m in $(oc get machines -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o name); do
        oc patch -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} ${m} --type=json --patch='[ { "op":"remove", "path": "/metadata/finalizers" }]' || true
        oc delete -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} ${m} || true
    done
    
    $ oc delete machineset -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --all || true
  4. Delete the cluster object by entering these commands:

    # Cluster
    $ C_NAME=$(oc get cluster -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o name)
    $ oc patch -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} ${C_NAME} --type=json --patch='[ { "op":"remove", "path": "/metadata/finalizers" }]'
    $ oc delete cluster.cluster.x-k8s.io -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --all
  5. Delete the AWS machines (Kubernetes objects) by entering these commands. Do not worry about deleting the real AWS machines. The cloud instances will not be affected.

    # AWS Machines
    for m in $(oc get awsmachine.infrastructure.cluster.x-k8s.io -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} -o name)
    do
        oc patch -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} ${m} --type=json --patch='[ { "op":"remove", "path": "/metadata/finalizers" }]' || true
        oc delete -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} ${m} || true
    done
  6. Delete the HostedControlPlane and ControlPlane HC namespace objects by entering these commands:

    # Delete HCP and ControlPlane HC NS
    $ oc patch -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} hostedcontrolplane.hypershift.openshift.io ${HC_CLUSTER_NAME} --type=json --patch='[ { "op":"remove", "path": "/metadata/finalizers" }]'
    $ oc delete hostedcontrolplane.hypershift.openshift.io -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} --all
    $ oc delete ns ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME} || true
  7. Delete the HostedCluster and HC namespace objects by entering these commands:

    # Delete HC and HC Namespace
    $ oc -n ${HC_CLUSTER_NS} patch hostedclusters ${HC_CLUSTER_NAME} -p '{"metadata":{"finalizers":null}}' --type merge || true
    $ oc delete hc -n ${HC_CLUSTER_NS} ${HC_CLUSTER_NAME}  || true
    $ oc delete ns ${HC_CLUSTER_NS} || true

Verification

  • To verify that everything works, enter these commands:

    # Validations
    $ export KUBECONFIG=${MGMT2_KUBECONFIG}
    
    $ oc get hc -n ${HC_CLUSTER_NS}
    $ oc get np -n ${HC_CLUSTER_NS}
    $ oc get pod -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}
    $ oc get machines -n ${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}
    
    # Inside the HostedCluster
    $ export KUBECONFIG=${HC_KUBECONFIG}
    $ oc get clusterversion
    $ oc get nodes

Next steps

Delete the OVN pods in the hosted cluster so that you can connect to the new OVN control plane that runs in the new management cluster:

  1. Load the KUBECONFIG environment variable with the hosted cluster’s kubeconfig path.
  2. Enter this command:

    $ oc delete pod -n openshift-ovn-kubernetes --all

Chapter 9. Troubleshooting hosted control planes

If you encounter issues with hosted control planes, see the following information to guide you through troubleshooting.

9.1. Gathering information to troubleshoot hosted control planes

When you need to troubleshoot an issue with hosted control plane clusters, you can gather information by running the must-gather command. The command generates output for the management cluster and the hosted cluster.

The output for the management cluster contains the following content:

  • Cluster-scoped resources: These resources are node definitions of the management cluster.
  • The hypershift-dump compressed file: This file is useful if you need to share the content with other people.
  • Namespaced resources: These resources include all of the objects from the relevant namespaces, such as config maps, services, events, and logs.
  • Network logs: These logs include the OVN northbound and southbound databases and the status for each one.
  • Hosted clusters: This level of output involves all of the resources inside of the hosted cluster.

The output for the hosted cluster contains the following content:

  • Cluster-scoped resources: These resources include all of the cluster-wide objects, such as nodes and CRDs.
  • Namespaced resources: These resources include all of the objects from the relevant namespaces, such as config maps, services, events, and logs.

Although the output does not contain any secret objects from the cluster, it can contain references to the names of secrets.

Prerequisites

  • You must have cluster-admin access to the management cluster.
  • You need the name value for the HostedCluster resource and the namespace where the CR is deployed.
  • You must have the hcp command line interface installed. For more information, see Installing the hosted control planes command line interface.
  • You must have the OpenShift CLI (oc) installed.
  • You must ensure that the kubeconfig file is loaded and is pointing to the management cluster.

Procedure

  • To gather the output for troubleshooting, enter the following command:

    $ oc adm must-gather --image=registry.redhat.io/multicluster-engine/must-gather-rhel9:v<mce_version> \
      /usr/bin/gather hosted-cluster-namespace=HOSTEDCLUSTERNAMESPACE hosted-cluster-name=HOSTEDCLUSTERNAME \
      --dest-dir=NAME ; tar -cvzf NAME.tgz NAME

    where:

    • You replace <mce_version> with the version of multicluster engine Operator that you are using; for example, 2.4.
    • The hosted-cluster-namespace=HOSTEDCLUSTERNAMESPACE parameter is optional. If you do not include it, the command runs as though the hosted cluster is in the default namespace, which is clusters.
    • The --dest-dir=NAME parameter is optional. Specify that parameter if you want to save the results of the command to a compressed file, replacing NAME with the name of the directory where you want to save the results.

9.2. Pausing the reconciliation of a hosted cluster and hosted control plane

If you are a cluster instance administrator, you can pause the reconciliation of a hosted cluster and hosted control plane. You might want to pause reconciliation when you back up and restore an etcd database or when you need to debug problems with a hosted cluster or hosted control plane.

Procedure

  1. To pause reconciliation for a hosted cluster and hosted control plane, populate the pausedUntil field of the HostedCluster resource.

    • To pause the reconciliation until a specific time, enter the following command:

      $ oc patch -n <hosted_cluster_namespace> hostedclusters/<hosted_cluster_name> -p '{"spec":{"pausedUntil":"<timestamp>"}}' --type=merge 1
      1
      Specify a timestamp in the RFC339 format, for example, 2024-03-03T03:28:48Z. The reconciliation is paused until the specified time is passed.
    • To pause the reconciliation indefinitely, enter the following command:

      $ oc patch -n <hosted_cluster_namespace> hostedclusters/<hosted_cluster_name> -p '{"spec":{"pausedUntil":"true"}}' --type=merge

      The reconciliation is paused until you remove the field from the HostedCluster resource.

      When the pause reconciliation field is populated for the HostedCluster resource, the field is automatically added to the associated HostedControlPlane resource.

  2. To remove the pausedUntil field, enter the following patch command:

    $ oc patch -n <hosted_cluster_namespace> hostedclusters/<hosted_cluster_name> -p '{"spec":{"pausedUntil":null}}' --type=merge

9.3. Scaling down the data plane to zero

If you are not using the hosted control plane, to save the resources and cost you can scale down a data plane to zero.

Note

Ensure you are prepared to scale down the data plane to zero. Because the workload from the worker nodes disappears after scaling down.

Procedure

  1. Set the kubeconfig file to access the hosted cluster by running the following command:

    $ export KUBECONFIG=<install_directory>/auth/kubeconfig
  2. Get the name of the NodePool resource associated to your hosted cluster by running the following command:

    $ oc get nodepool --namespace <HOSTED_CLUSTER_NAMESPACE>
  3. Optional: To prevent the pods from draining, add the nodeDrainTimeout field in the NodePool resource by running the following command:

    $ oc edit nodepool <nodepool_name>  --namespace <hosted_cluster_namespace>

    Example output

    apiVersion: hypershift.openshift.io/v1alpha1
    kind: NodePool
    metadata:
    # ...
      name: nodepool-1
      namespace: clusters
    # ...
    spec:
      arch: amd64
      clusterName: clustername 1
      management:
        autoRepair: false
        replace:
          rollingUpdate:
            maxSurge: 1
            maxUnavailable: 0
          strategy: RollingUpdate
        upgradeType: Replace
      nodeDrainTimeout: 0s 2
    # ...

    1
    Defines the name of your hosted cluster.
    2
    Specifies the total amount of time that the controller spends to drain a node. By default, the nodeDrainTimeout: 0s setting blocks the node draining process.
    Note

    To allow the node draining process to continue for a certain period of time, you can set the value of the nodeDrainTimeout field accordingly, for example, nodeDrainTimeout: 1m.

  4. Scale down the NodePool resource associated to your hosted cluster by running the following command:

    $ oc scale nodepool/<NODEPOOL_NAME> --namespace <HOSTED_CLUSTER_NAMESPACE> --replicas=0
    Note

    After scaling down the data plan to zero, some pods in the control plane stay in the Pending status and the hosted control plane stays up and running. If necessary, you can scale up the NodePool resource.

  5. Optional: Scale up the NodePool resource associated to your hosted cluster by running the following command:

    $ oc scale nodepool/<NODEPOOL_NAME> --namespace <HOSTED_CLUSTER_NAMESPACE> --replicas=1

    After rescaling the NodePool resource, wait for couple of minutes for the NodePool resource to become available in a Ready state.

Verification

  • Verify that the value for the nodeDrainTimeout field is greater than 0s by running the following command:

    $ oc get nodepool -n <hosted_cluster_namespace> <nodepool_name> -ojsonpath='{.spec.nodeDrainTimeout}'

Additional resources

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