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Chapter 8. High availability for hosted control planes


8.1. About high availability for hosted control planes

You can maintain high availability (HA) of hosted control planes by implementing the following actions:

  • Recover etcd members for a hosted cluster.
  • Back up and restore etcd for a hosted cluster.
  • Perform a disaster recovery process for a hosted cluster.

8.1.1. Impact of the failed management cluster component

If the management cluster component fails, your workload remains unaffected. In the OpenShift Container Platform management cluster, the control plane is decoupled from the data plane to provide resiliency.

The following table covers the impact of a failed management cluster component on the control plane and the data plane. However, the table does not cover all scenarios for the management cluster component failures.

Table 8.1. Impact of the failed component on hosted control planes
Name of the failed componentHosted control plane API statusHosted cluster data plane status

Worker node

Available

Available

Availability zone

Available

Available

Management cluster control plane

Available

Available

Management cluster control plane and worker nodes

Not available

Available

8.2. 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.

8.2.1. 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 openshift-etcd -c etcd <etcd_pod_name>
  2. Print the health status of an etcd cluster by entering the following command:

    sh-4.4# etcdctl endpoint status -w table

    Example output

    +------------------------------+-----------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
    |          ENDPOINT            |       ID        | VERSION | DB SIZE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS |
    +------------------------------+-----------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
    | https://192.168.1xxx.20:2379 | 8fxxxxxxxxxx    |  3.5.12 |  123 MB |     false |      false |        10 |     180156 |             180156 |        |
    | https://192.168.1xxx.21:2379 | a5xxxxxxxxxx    |  3.5.12 |  122 MB |     false |      false |        10 |     180156 |             180156 |        |
    | https://192.168.1xxx.22:2379 | 7cxxxxxxxxxx    |  3.5.12 |  124 MB |      true |      false |        10 |     180156 |             180156 |        |
    +-----------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+

8.2.2. 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 openshift-etcd

    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 pods etcd-2 -n openshift-etcd

Verification

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

    $ oc get pods -l app=etcd -n openshift-etcd

    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

8.3. 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.

8.3.1. 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

8.4. 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.

8.4.1. 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.

8.4.2. 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.

8.5. Backing up and restoring a hosted cluster on OpenShift Virtualization

You can back up and restore a hosted cluster on OpenShift Virtualization to fix failures.

8.5.1. Backing up a hosted cluster on OpenShift Virtualization

When you back up a hosted cluster on OpenShift Virtualization, the hosted cluster can remain running. The backup contains the hosted control plane components and the etcd for the hosted cluster.

When the hosted cluster is not running compute nodes on external infrastructure, hosted cluster workload data that is stored in persistent volume claims (PVCs) that are provisioned by KubeVirt CSI are also backed up. The backup does not contain any KubeVirt virtual machines (VMs) that are used as compute nodes. Those VMs are automatically re-created after the restore process is completed.

Procedure

  1. Create a Velero backup resource by creating a YAML file that is similar to the following example:

    apiVersion: velero.io/v1
    kind: Backup
    metadata:
      name: hc-clusters-hosted-backup
      namespace: openshift-adp
      labels:
        velero.io/storage-location: default
    spec:
      includedNamespaces: 1
      - clusters
      - clusters-hosted
      includedResources:
      - sa
      - role
      - rolebinding
      - deployment
      - statefulset
      - pv
      - pvc
      - bmh
      - configmap
      - infraenv
      - priorityclasses
      - pdb
      - hostedcluster
      - nodepool
      - secrets
      - hostedcontrolplane
      - cluster
      - datavolume
      - service
      - route
      excludedResources: [ ]
      labelSelector: 2
        matchExpressions:
        - key: 'hypershift.openshift.io/is-kubevirt-rhcos'
          operator: 'DoesNotExist'
      storageLocation: default
      preserveNodePorts: true
      ttl: 4h0m0s
      snapshotMoveData: true 3
      datamover: "velero" 4
      defaultVolumesToFsBackup: false 5
    1
    This field selects the namespaces from the objects to back up. Include namespaces from both the hosted cluster and the hosted control plane. In this example, clusters is a namespace from the hosted cluster and clusters-hosted is a namespace from the hosted control plane. By default, the HostedControlPlane namespace is clusters-<hosted_cluster_name>.
    2
    The boot image of the VMs that are used as the hosted cluster nodes are stored in large PVCs. To reduce backup time and storage size, you can filter those PVCs out of the backup by adding this label selector.
    3
    This field and the datamover field enable automatically uploading the CSI VolumeSnapshots to remote cloud storage.
    4
    This field and the snapshotMoveData field enable automatically uploading the CSI VolumeSnapshots to remote cloud storage.
    5
    This field indicates whether pod volume file system backup is used for all volumes by default. Set this value to false to back up the PVCs that you want.
  2. Apply the changes to the YAML file by entering the following command:

    $ oc apply -f <backup_file_name>.yaml

    Replace <backup_file_name> with the name of your file.

  3. Monitor the backup process in the backup object status and in the Velero logs.

    • To monitor the backup object status, enter the following command:

      $ watch "oc get backups.velero.io -n openshift-adp <backup_file_name> -o jsonpath='{.status}' | jq"
    • To monitor the Velero logs, enter the following command:

      $ oc logs -n openshift-adp -ldeploy=velero -f

Verification

  • When the status.phase field is Completed, the backup process is considered complete.

8.5.2. Restoring a hosted cluster on OpenShift Virtualization

After you back up a hosted cluster on OpenShift Virtualization, you can restore the backup.

Note

The restore process can be completed only on the same management cluster where you created the backup.

Procedure

  1. Ensure that no pods or persistent volume claims (PVCs) are running in the HostedControlPlane namespace.
  2. Delete the following objects from the management cluster:

    • HostedCluster
    • NodePool
    • PVCs
  3. Create a restoration manifest YAML file that is similar to the following example:

    apiVersion: velero.io/v1
    kind: Restore
    metadata:
      name: hc-clusters-hosted-restore
      namespace: openshift-adp
    spec:
      backupName: hc-clusters-hosted-backup
      restorePVs: true 1
      existingResourcePolicy: update 2
      excludedResources:
      - nodes
      - events
      - events.events.k8s.io
      - backups.velero.io
      - restores.velero.io
      - resticrepositories.velero.io
    1
    This field starts the recovery of pods with the included persistent volumes.
    2
    Setting existingResourcePolicy to update ensures that any existing objects are overwritten with backup content. This action can cause issues with objects that contain immutable fields, which is why you deleted the HostedCluster, node pools, and PVCs. If you do not set this policy, the Velero engine skips the restoration of objects that already exist.
  4. Apply the changes to the YAML file by entering the following command:

    $ oc apply -f <restore_resource_file_name>.yaml

    Replace <restore_resource_file_name> with the name of your file.

  5. Monitor the restore process by checking the restore status field and the Velero logs.

    • To check the restore status field, enter the following command:

      $ watch "oc get restores.velero.io -n openshift-adp <backup_file_name> -o jsonpath='{.status}' | jq"
    • To check the Velero logs, enter the following command:

      $ oc logs -n openshift-adp -ldeploy=velero -f

Verification

  • When the status.phase field is Completed, the restore process is considered complete.

Next steps

  • After some time, the KubeVirt VMs are created and join the hosted cluster as compute nodes. Make sure that the hosted cluster workloads are running again as expected.

8.6. 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.

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.

8.6.1. 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

8.6.2. 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.

8.6.3. 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.

8.6.4. 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

8.7. Disaster recovery for a hosted cluster by using OADP

You can use the OpenShift API for Data Protection (OADP) Operator to perform disaster recovery on Amazon Web Services (AWS) and bare metal.

The disaster recovery process with OpenShift API for Data Protection (OADP) involves the following steps:

  1. Preparing your platform, such as Amazon Web Services or bare metal, to use OADP
  2. Backing up the data plane workload
  3. Backing up the control plane workload
  4. Restoring a hosted cluster by using OADP

8.7.1. Prerequisites

You must meet the following prerequisites on the management cluster:

  • You installed the OADP Operator.
  • You created a storage class.
  • You have access to the cluster with cluster-admin privileges.
  • You have access to the OADP subscription through a catalog source.
  • You have access to a cloud storage provider that is compatible with OADP, such as S3, Microsoft Azure, Google Cloud Platform, or MinIO.
  • In a disconnected environment, you have access to a self-hosted storage provider, for example Red Hat OpenShift Data Foundation or MinIO, that is compatible with OADP.
  • Your hosted control planes pods are up and running.

8.7.2. Preparing AWS to use OADP

To perform disaster recovery for a hosted cluster, you can use OpenShift API for Data Protection (OADP) on Amazon Web Services (AWS) S3 compatible storage. After creating the DataProtectionApplication object, new velero deployment and node-agent pods are created in the openshift-adp namespace.

To prepare AWS to use OADP, see "Configuring the OpenShift API for Data Protection with Multicloud Object Gateway".

Next steps

  • Backing up the data plane workload
  • Backing up the control plane workload

8.7.3. Preparing bare metal to use OADP

To perform disaster recovery for a hosted cluster, you can use OpenShift API for Data Protection (OADP) on bare metal. After creating the DataProtectionApplication object, new velero deployment and node-agent pods are created in the openshift-adp namespace.

To prepare bare metal to use OADP, see "Configuring the OpenShift API for Data Protection with AWS S3 compatible storage".

Next steps

  • Backing up the data plane workload
  • Backing up the control plane workload

8.7.4. Backing up the data plane workload

If the data plane workload is not important, you can skip this procedure. To back up the data plane workload by using the OADP Operator, see "Backing up applications".

Additional resources

Next steps

  • Restoring a hosted cluster by using OADP

8.7.5. Backing up the control plane workload

You can back up the control plane workload by creating the Backup custom resource (CR).

To monitor and observe the backup process, see "Observing the backup and restore process".

Procedure

  1. Pause the reconciliation of the HostedCluster resource by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      patch hostedcluster -n <hosted_cluster_namespace> <hosted_cluster_name> \
      --type json -p '[{"op": "add", "path": "/spec/pausedUntil", "value": "true"}]'
  2. Get the infrastructure ID of your hosted cluster by running the following command:

    $ oc get hostedcluster -n local-cluster <hosted_cluster_name> -o=jsonpath="{.spec.infraID}"

    Note the infrastructure ID to use in the next step.

  3. Pause the reconciliation of the cluster.cluster.x-k8s.io resource by running the following command:

    $ oc patch cluster.cluster.x-k8s.io \
      -n local-cluster-<hosted_cluster_name> <hosted_cluster_infra_id> \
      --type json -p '[{"op": "add", "path": "/spec/paused", "value": true}]'
  4. Pause the reconciliation of the NodePool resource by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      patch nodepool -n <hosted_cluster_namespace> <node_pool_name> \
      --type json -p '[{"op": "add", "path": "/spec/pausedUntil", "value": "true"}]'
  5. Pause the reconciliation of the AgentCluster resource by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      annotate agentcluster -n <hosted_control_plane_namespace>  \
      cluster.x-k8s.io/paused=true --all'
  6. Pause the reconciliation of the AgentMachine resource by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      annotate agentmachine -n <hosted_control_plane_namespace>  \
      cluster.x-k8s.io/paused=true --all'
  7. Annotate the HostedCluster resource to prevent the deletion of the hosted control plane namespace by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      annotate hostedcluster -n <hosted_cluster_namespace> <hosted_cluster_name> \
      hypershift.openshift.io/skip-delete-hosted-controlplane-namespace=true
  8. Create a YAML file that defines the Backup CR:

    Example 8.1. Example backup-control-plane.yaml file

    apiVersion: velero.io/v1
    kind: Backup
    metadata:
      name: <backup_resource_name> 1
      namespace: openshift-adp
      labels:
        velero.io/storage-location: default
    spec:
      hooks: {}
      includedNamespaces: 2
      - <hosted_cluster_namespace> 3
      - <hosted_control_plane_namespace> 4
      includedResources:
      - sa
      - role
      - rolebinding
      - pod
      - pvc
      - pv
      - bmh
      - configmap
      - infraenv 5
      - priorityclasses
      - pdb
      - agents
      - hostedcluster
      - nodepool
      - secrets
      - hostedcontrolplane
      - cluster
      - agentcluster
      - agentmachinetemplate
      - agentmachine
      - machinedeployment
      - machineset
      - machine
      excludedResources: []
      storageLocation: default
      ttl: 2h0m0s
      snapshotMoveData: true 6
      datamover: "velero" 7
      defaultVolumesToFsBackup: true 8
    1
    Replace backup_resource_name with the name of your Backup resource.
    2
    Selects specific namespaces to back up objects from them. You must include your hosted cluster namespace and the hosted control plane namespace.
    3
    Replace <hosted_cluster_namespace> with the name of the hosted cluster namespace, for example, clusters.
    4
    Replace <hosted_control_plane_namespace> with the name of the hosted control plane namespace, for example, clusters-hosted.
    5
    You must create the infraenv resource in a separate namespace. Do not delete the infraenv resource during the backup process.
    6 7
    Enables the CSI volume snapshots and uploads the control plane workload automatically to the cloud storage.
    8
    Sets the fs-backup backing up method for persistent volumes (PVs) as default. This setting is useful when you use a combination of Container Storage Interface (CSI) volume snapshots and the fs-backup method.
    Note

    If you want to use CSI volume snapshots, you must add the backup.velero.io/backup-volumes-excludes=<pv_name> annotation to your PVs.

  9. Apply the Backup CR by running the following command:

    $ oc apply -f backup-control-plane.yaml

Verification

  • Verify if the value of the status.phase is Completed by running the following command:

    $ oc get backups.velero.io <backup_resource_name> -n openshift-adp -o jsonpath='{.status.phase}'

Next steps

  • Restoring a hosted cluster by using OADP

8.7.6. Restoring a hosted cluster by using OADP

You can restore the hosted cluster by creating the Restore custom resource (CR).

  • If you are using an in-place update, InfraEnv does not need spare nodes. You need to re-provision the worker nodes from the new management cluster.
  • If you are using a replace update, you need some spare nodes for InfraEnv to deploy the worker nodes.
Important

After you back up your hosted cluster, you must destroy it to initiate the restoring process. To initiate node provisioning, you must back up workloads in the data plane before deleting the hosted cluster.

Prerequisites

To monitor and observe the backup process, see "Observing the backup and restore process".

Procedure

  1. Verify that no pods and persistent volume claims (PVCs) are present in the hosted control plane namespace by running the following command:

    $ oc get pod pvc -n <hosted_control_plane_namespace>

    Expected output

    No resources found

  2. Create a YAML file that defines the Restore CR:

    Example restore-hosted-cluster.yaml file

    apiVersion: velero.io/v1
    kind: Restore
    metadata:
      name: <restore_resource_name> 1
      namespace: openshift-adp
    spec:
      backupName: <backup_resource_name> 2
      restorePVs: true 3
      existingResourcePolicy: update 4
      excludedResources:
      - nodes
      - events
      - events.events.k8s.io
      - backups.velero.io
      - restores.velero.io
      - resticrepositories.velero.io

    1
    Replace <restore_resource_name> with the name of your Restore resource.
    2
    Replace <backup_resource_name> with the name of your Backup resource.
    3
    Initiates the recovery of persistent volumes (PVs) and its pods.
    4
    Ensures that the existing objects are overwritten with the backed up content.
    Important

    You must create the infraenv resource in a separate namespace. Do not delete the infraenv resource during the restore process. The infraenv resource is mandatory for the new nodes to be reprovisioned.

  3. Apply the Restore CR by running the following command:

    $ oc apply -f restore-hosted-cluster.yaml
  4. Verify if the value of the status.phase is Completed by running the following command:

    $ oc get hostedcluster <hosted_cluster_name> -n <hosted_cluster_namespace> -o jsonpath='{.status.phase}'
  5. After the restore process is complete, start the reconciliation of the HostedCluster and NodePool resources that you paused during backing up of the control plane workload:

    1. Start the reconciliation of the HostedCluster resource by running the following command:

      $ oc --kubeconfig <management_cluster_kubeconfig_file> \
        patch hostedcluster -n <hosted_cluster_namespace> <hosted_cluster_name> \
        --type json -p '[{"op": "add", "path": "/spec/pausedUntil", "value": "false"}]'
    2. Start the reconciliation of the NodePool resource by running the following command:

      $ oc --kubeconfig <management_cluster_kubeconfig_file> \
        patch nodepool -n <hosted_cluster_namespace> <node_pool_name> \
        --type json -p '[{"op": "add", "path": "/spec/pausedUntil", "value": "false"}]'
  6. Start the reconciliation of the Agent provider resources that you paused during backing up of the control plane workload:

    1. Start the reconciliation of the AgentCluster resource by running the following command:

      $ oc --kubeconfig <management_cluster_kubeconfig_file> \
        annotate agentcluster -n <hosted_control_plane_namespace>  \
        cluster.x-k8s.io/paused- --overwrite=true --all
    2. Start the reconciliation of the AgentMachine resource by running the following command:

      $ oc --kubeconfig <management_cluster_kubeconfig_file> \
        annotate agentmachine -n <hosted_control_plane_namespace>  \
        cluster.x-k8s.io/paused- --overwrite=true --all
  7. Remove the hypershift.openshift.io/skip-delete-hosted-controlplane-namespace- annotation in the HostedCluster resource to avoid manually deleting the hosted control plane namespace by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      annotate hostedcluster -n <hosted_cluster_namespace> <hosted_cluster_name> \
      hypershift.openshift.io/skip-delete-hosted-controlplane-namespace- \
      --overwrite=true --all
  8. Scale the NodePool resource to the desired number of replicas by running the following command:

    $ oc --kubeconfig <management_cluster_kubeconfig_file> \
      scale nodepool -n <hosted_cluster_namespace> <node_pool_name> \
      --replicas <replica_count> 1
    1
    Replace <replica_count> by an integer value, for example, 3.

8.7.7. Observing the backup and restore process

When using OpenShift API for Data Protection (OADP) to backup and restore a hosted cluster, you can monitor and observe the process.

Procedure

  1. Observe the backup process by running the following command:

    $ watch "oc get backups.velero.io -n openshift-adp <backup_resource_name> -o jsonpath='{.status}'"
  2. Observe the restore process by running the following command:

    $ watch "oc get restores.velero.io -n openshift-adp <backup_resource_name> -o jsonpath='{.status}'"
  3. Observe the Velero logs by running the following command:

    $ oc logs -n openshift-adp -ldeploy=velero -f
  4. Observe the progress of all of the OADP objects by running the following command:

    $ watch "echo BackupRepositories:;echo;oc get backuprepositories.velero.io -A;echo; echo BackupStorageLocations: ;echo; oc get backupstoragelocations.velero.io -A;echo;echo DataUploads: ;echo;oc get datauploads.velero.io -A;echo;echo DataDownloads: ;echo;oc get datadownloads.velero.io -n openshift-adp; echo;echo VolumeSnapshotLocations: ;echo;oc get volumesnapshotlocations.velero.io -A;echo;echo Backups:;echo;oc get backup -A; echo;echo Restores:;echo;oc get restore -A"

8.7.8. Using the velero CLI to describe the Backup and Restore resources

When using OpenShift API for Data Protection, you can get more details of the Backup and Restore resources by using the velero command-line interface (CLI).

Procedure

  1. Create an alias to use the velero CLI from a container by running the following command:

    $ alias velero='oc -n openshift-adp exec deployment/velero -c velero -it -- ./velero'
  2. Get details of your Restore custom resource (CR) by running the following command:

    $ velero restore describe <restore_resource_name> --details 1
    1
    Replace <restore_resource_name> with the name of your Restore resource.
  3. Get details of your Backup CR by running the following command:

    $ velero restore describe <backup_resource_name> --details 1
    1
    Replace <backup_resource_name> with the name of your Backup resource.
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