Backup, restore, and disaster recovery for hosted control planes
If you need to back up and restore etcd on a hosted cluster or provide disaster recovery for a hosted cluster, see the following procedures.
Recovering etcd pods for hosted clusters
In hosted clusters, etcd pods run as part of a stateful set. The stateful set relies on persistent storage to store etcd data for each member. In a highly available control plane, the size of the stateful set is three pods, and each member has its own persistent volume claim.
Checking the status of a hosted cluster
To check the status of your hosted cluster, complete the following steps.
Procedure
Enter the running etcd pod that you want to check by entering the following command:
$ oc rsh -n <control_plane_namespace> -c etcd etcd-0
Set up the etcdctl environment by entering the following commands:
sh-4.4$ export ETCDCTL_API=3
sh-4.4$ export ETCDCTL_CACERT=/etc/etcd/tls/etcd-ca/ca.crt
sh-4.4$ export ETCDCTL_CERT=/etc/etcd/tls/client/etcd-client.crt
sh-4.4$ export ETCDCTL_KEY=/etc/etcd/tls/client/etcd-client.key
sh-4.4$ export ETCDCTL_ENDPOINTS=https://etcd-client:2379
Print the endpoint status for each cluster member by entering the following command:
sh-4.4$ etcdctl endpoint health --cluster -w table
Recovering an etcd member for a hosted cluster
An etcd member of a 3-node cluster might fail because of corrupted or missing data. To recover the etcd member, complete the following steps.
Procedure
If you need to confirm that the etcd member is failing, enter the following command:
$ oc get pods -l app=etcd -n <control_plane_namespace>
The output resembles this example if the etcd member is failing:
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
Delete the persistent volume claim of the failing etcd member and the pod by entering the following command:
$ oc delete pvc/data-etcd-2 pod/etcd-2 --wait=false
When the pod restarts, verify that the etcd member is added back to the etcd cluster and is correctly functioning by entering the following command:
$ oc get pods -l app=etcd -n $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
Recovering an etcd cluster from a quorum loss
If multiple members of the etcd cluster have lost data or return a CrashLoopBackOff
status, it can cause an etcd quorum loss. You must restore your etcd cluster from a snapshot.
This procedure requires API downtime. |
Prerequisites
- The
oc
andjq
binaries have been installed.
Procedure
First, set up your environment variables and scale down the API servers:
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}"
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
Scale down the API servers by entering the following commands:
Scale down the
kube-apiserver
:$ oc scale -n ${CONTROL_PLANE_NAMESPACE} deployment/kube-apiserver --replicas=0
Scale down the
openshift-apiserver
:$ oc scale -n ${CONTROL_PLANE_NAMESPACE} deployment/openshift-apiserver --replicas=0
Scale down the
openshift-oauth-apiserver
:$ oc scale -n ${CONTROL_PLANE_NAMESPACE} deployment/openshift-oauth-apiserver --replicas=0
Next, take a snapshot of etcd by using one of the following methods:
Use a previously backed-up snapshot of etcd.
If you have an available etcd pod, take a snapshot from the active etcd pod by completing the following steps:
List etcd pods by entering the following command:
$ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd
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
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
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
Make a copy of the snapshot database from etcd persistent storage:
List etcd pods by entering the following command:
$ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd
Find a pod that is running and set its name as the value of
ETCD_POD: ETCD_POD=etcd-0
, and then copy its snapshot database by entering the following command:$ oc cp -c etcd ${CONTROL_PLANE_NAMESPACE}/${ETCD_POD}:/var/lib/data/member/snap/db /tmp/etcd.snapshot.db
Next, scale down the etcd statefulset by entering the following command:
$ oc scale -n ${CONTROL_PLANE_NAMESPACE} statefulset/etcd --replicas=0
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
Create a pod to access the first etcd member’s data:
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 }')
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: $ETCD_IMAGE
volumeMounts:
- name: data
mountPath: /var/lib
command:
- /usr/bin/bash
args:
- -c
- |-
while true; do
sleep 1000
done
volumes:
- name: data
persistentVolumeClaim:
claimName: data-etcd-0
EOF
Check the status of the
etcd-data
pod and wait for it to be running by entering the following command:$ oc get -n ${CONTROL_PLANE_NAMESPACE} pods -l app=etcd-data
Get the name of the
etcd-data
pod by entering the following command:$ DATA_POD=$(oc get -n ${CONTROL_PLANE_NAMESPACE} pods --no-headers -l app=etcd-data -o name | cut -d/ -f2)
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
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
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
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
Delete data access deployment by entering the following command:
$ oc delete -n ${CONTROL_PLANE_NAMESPACE} deployment/etcd-data
Scale up the etcd cluster by entering the following command:
$ oc scale -n ${CONTROL_PLANE_NAMESPACE} statefulset/etcd --replicas=3
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
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
Restore reconciliation of the hosted cluster by entering the following command:
$ oc patch -n ${CLUSTER_NAMESPACE} hostedclusters/${CLUSTER_NAME} -p '{"spec":{"pausedUntil":""}}' --type=merge
Backing up and restoring etcd on a hosted cluster on AWS
If you use hosted control planes for OKD, the process to back up and restore etcd is different from the usual etcd backup process.
The following procedures are specific to hosted control planes on AWS.
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. |
Taking a snapshot of etcd on a hosted cluster
As part of the process to back up etcd for a hosted cluster, you take a snapshot of etcd. After you take the snapshot, you can restore it, for example, as part of a disaster recovery operation.
This procedure requires API downtime. |
Procedure
Pause reconciliation of the hosted cluster by entering this command:
$ oc patch -n clusters hostedclusters/${CLUSTER_NAME} -p '{"spec":{"pausedUntil":"'${PAUSED_UNTIL}'"}}' --type=merge
Stop all etcd-writer deployments by entering this command:
$ oc scale deployment -n ${HOSTED_CLUSTER_NAMESPACE} --replicas=0 kube-apiserver openshift-apiserver openshift-oauth-apiserver
Take an etcd snapshot by using the
exec
command in each etcd container:$ oc exec -it etcd-0 -n ${HOSTED_CLUSTER_NAMESPACE} -- 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 etcd-0 -n ${HOSTED_CLUSTER_NAMESPACE} -- env ETCDCTL_API=3 /usr/bin/etcdctl -w table snapshot status /var/lib/data/snapshot.db
Copy the snapshot data to a location where you can retrieve it later, such as an S3 bucket, as shown in the following example.
The following example uses signature version 2. If you are in a region that supports signature version 4, such as the us-east-2 region, use signature version 4. Otherwise, if you use signature version 2 to copy the snapshot to an S3 bucket, the upload fails and signature version 2 is deprecated.
Example
BUCKET_NAME=somebucket
FILEPATH="/${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
If you want to be able to restore the snapshot on a new cluster later, save the encryption secret that the hosted cluster references, as shown in this example:
Example
oc get hostedcluster $CLUSTER_NAME -o=jsonpath='{.spec.secretEncryption.aescbc}'
{"activeKey":{"name":"CLUSTER_NAME-etcd-encryption-key"}}
# Save this secret, or the key it contains so the etcd data can later be decrypted
oc get secret ${CLUSTER_NAME}-etcd-encryption-key -o=jsonpath='{.data.key}'
Next steps
Restore the etcd snapshot.
Restoring an etcd snapshot on a hosted cluster
If you have a snapshot of etcd from your hosted cluster, you can restore it. Currently, you can restore an etcd snapshot only during cluster creation.
To restore an etcd snapshot, you modify the output from the create cluster --render
command and define a restoreSnapshotURL
value in the etcd section of the HostedCluster
specification.
Prerequisites
You took an etcd snapshot on a hosted cluster.
Procedure
On the
aws
command-line interface (CLI), create a pre-signed URL so that you can download your etcd snapshot from S3 without passing credentials to the etcd deployment:ETCD_SNAPSHOT=${ETCD_SNAPSHOT:-"s3://${BUCKET_NAME}/${CLUSTER_NAME}-snapshot.db"}
ETCD_SNAPSHOT_URL=$(aws s3 presign ${ETCD_SNAPSHOT})
Modify the
HostedCluster
specification to refer to the URL:spec:
etcd:
managed:
storage:
persistentVolume:
size: 4Gi
type: PersistentVolume
restoreSnapshotURL:
- "${ETCD_SNAPSHOT_URL}"
managementType: Managed
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.
Disaster recovery for a hosted cluster within an AWS region
In a situation where you need disaster recovery (DR) for a hosted cluster, you can recover a hosted cluster to the same region within AWS. For example, you need DR when the upgrade of a management cluster fails and the hosted cluster is in a read-only state.
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 DR process involves three main steps:
Backing up the hosted cluster on the source management cluster
Restoring the hosted cluster on a destination management cluster
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 will not affect the services that are running on the worker nodes.
Both the source management cluster and the destination management cluster must have the Example: External DNS flags
That way, the server URL ends with If you do not include the |
Example environment and context
Consider an scenario where you have three clusters to restore. Two are management clusters, and one is a hosted cluster. You can restore either the control plane only or the control plane and the nodes. Before you begin, you need the following information:
Source MGMT Namespace: The source management namespace
Source MGMT ClusterName: The source management cluster name
Source MGMT Kubeconfig: The source management
kubeconfig
fileDestination MGMT Kubeconfig: The destination management
kubeconfig
fileHC Kubeconfig: The hosted cluster
kubeconfig
fileSSH key file: The SSH public key
Pull secret: The pull secret file to access the release images
AWS credentials
AWS region
Base domain: The DNS base domain to use as an external DNS
S3 bucket name: The bucket in the AWS region where you plan to upload the etcd backup
This information is shown in the following example environment variables.
Example environment variables
SSH_KEY_FILE=${HOME}/.ssh/id_rsa.pub
BASE_PATH=${HOME}/hypershift
BASE_DOMAIN="aws.sample.com"
PULL_SECRET_FILE="${HOME}/pull_secret.json"
AWS_CREDS="${HOME}/.aws/credentials"
AWS_ZONE_ID="Z02718293M33QHDEQBROL"
CONTROL_PLANE_AVAILABILITY_POLICY=SingleReplica
HYPERSHIFT_PATH=${BASE_PATH}/src/hypershift
HYPERSHIFT_CLI=${HYPERSHIFT_PATH}/bin/hypershift
HYPERSHIFT_IMAGE=${HYPERSHIFT_IMAGE:-"quay.io/${USER}/hypershift:latest"}
NODE_POOL_REPLICAS=${NODE_POOL_REPLICAS:-2}
# MGMT Context
MGMT_REGION=us-west-1
MGMT_CLUSTER_NAME="${USER}-dev"
MGMT_CLUSTER_NS=${USER}
MGMT_CLUSTER_DIR="${BASE_PATH}/hosted_clusters/${MGMT_CLUSTER_NS}-${MGMT_CLUSTER_NAME}"
MGMT_KUBECONFIG="${MGMT_CLUSTER_DIR}/kubeconfig"
# MGMT2 Context
MGMT2_CLUSTER_NAME="${USER}-dest"
MGMT2_CLUSTER_NS=${USER}
MGMT2_CLUSTER_DIR="${BASE_PATH}/hosted_clusters/${MGMT2_CLUSTER_NS}-${MGMT2_CLUSTER_NAME}"
MGMT2_KUBECONFIG="${MGMT2_CLUSTER_DIR}/kubeconfig"
# Hosted Cluster Context
HC_CLUSTER_NS=clusters
HC_REGION=us-west-1
HC_CLUSTER_NAME="${USER}-hosted"
HC_CLUSTER_DIR="${BASE_PATH}/hosted_clusters/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}"
HC_KUBECONFIG="${HC_CLUSTER_DIR}/kubeconfig"
BACKUP_DIR=${HC_CLUSTER_DIR}/backup
BUCKET_NAME="${USER}-hosted-${MGMT_REGION}"
# DNS
AWS_ZONE_ID="Z07342811SH9AA102K1AC"
EXTERNAL_DNS_DOMAIN="hc.jpdv.aws.kerbeross.com"
Overview of the backup and restore process
The backup and restore process works as follows:
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.
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.
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.
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.
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.
You can manually back up and restore your hosted cluster, or you can run a script to complete the process. For more information about the script, see “Running a script to back up and restore a hosted cluster”.
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
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}
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
Back up etcd and upload the data to an S3 bucket by running this bash script:
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”.
Back up Kubernetes and OKD objects by entering the following commands. You need to back up the following objects:
HostedCluster
andNodePool
objects from the HostedCluster namespaceHostedCluster
secrets from the HostedCluster namespaceHostedControlPlane
from the Hosted Control Plane namespaceCluster
from the Hosted Control Plane namespaceAWSCluster
,AWSMachineTemplate
, andAWSMachine
from the Hosted Control Plane namespaceMachineDeployments
,MachineSets
, andMachines
from the Hosted Control Plane namespaceControlPlane
secrets from the Hosted Control Plane namespacemkdir -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
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.
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 OKD objects and the S3 bucket to verify that everything looks as expected.
Next steps
Restore your hosted cluster.
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.
Ensure that the |
Procedure
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
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}
Restore the secrets in the HC namespace by entering this command:
$ oc apply -f ${BACKUP_DIR}/namespaces/${HC_CLUSTER_NS}/secret-*
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-*
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}-${HC_CLUSTER_NAME}/machine-*
Restore the etcd data and the hosted cluster by running this bash script:
ETCD_PODS="etcd-0"
if [ "${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
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.
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.
Ensure that the |
Procedure
Scale the
deployment
andstatefulset
objects by entering these commands:Do not scale the stateful set if the value of its
spec.persistentVolumeClaimRetentionPolicy.whenScaled
field is set toDelete
, because this could lead to a loss of data.As a workaround, update the value of the
spec.persistentVolumeClaimRetentionPolicy.whenScaled
field toRetain
. Ensure that no controllers exist that reconcile the stateful set and would return the value back toDelete
, 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
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
Delete the
machine
andmachineset
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
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
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
Delete the
HostedControlPlane
andControlPlane
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
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:
Load the
KUBECONFIG
environment variable with the hosted cluster’s kubeconfig path.Enter this command:
$ oc delete pod -n openshift-ovn-kubernetes --all
Running a script to back up and restore a hosted cluster
To expedite the process to back up a hosted cluster and restore it within the same region on AWS, you can modify and run a script.
Procedure
Replace the variables in the following script with your information:
# Fill the Common variables to fit your environment, this is just a sample
SSH_KEY_FILE=${HOME}/.ssh/id_rsa.pub
BASE_PATH=${HOME}/hypershift
BASE_DOMAIN="aws.sample.com"
PULL_SECRET_FILE="${HOME}/pull_secret.json"
AWS_CREDS="${HOME}/.aws/credentials"
CONTROL_PLANE_AVAILABILITY_POLICY=SingleReplica
HYPERSHIFT_PATH=${BASE_PATH}/src/hypershift
HYPERSHIFT_CLI=${HYPERSHIFT_PATH}/bin/hypershift
HYPERSHIFT_IMAGE=${HYPERSHIFT_IMAGE:-"quay.io/${USER}/hypershift:latest"}
NODE_POOL_REPLICAS=${NODE_POOL_REPLICAS:-2}
# MGMT Context
MGMT_REGION=us-west-1
MGMT_CLUSTER_NAME="${USER}-dev"
MGMT_CLUSTER_NS=${USER}
MGMT_CLUSTER_DIR="${BASE_PATH}/hosted_clusters/${MGMT_CLUSTER_NS}-${MGMT_CLUSTER_NAME}"
MGMT_KUBECONFIG="${MGMT_CLUSTER_DIR}/kubeconfig"
# MGMT2 Context
MGMT2_CLUSTER_NAME="${USER}-dest"
MGMT2_CLUSTER_NS=${USER}
MGMT2_CLUSTER_DIR="${BASE_PATH}/hosted_clusters/${MGMT2_CLUSTER_NS}-${MGMT2_CLUSTER_NAME}"
MGMT2_KUBECONFIG="${MGMT2_CLUSTER_DIR}/kubeconfig"
# Hosted Cluster Context
HC_CLUSTER_NS=clusters
HC_REGION=us-west-1
HC_CLUSTER_NAME="${USER}-hosted"
HC_CLUSTER_DIR="${BASE_PATH}/hosted_clusters/${HC_CLUSTER_NS}-${HC_CLUSTER_NAME}"
HC_KUBECONFIG="${HC_CLUSTER_DIR}/kubeconfig"
BACKUP_DIR=${HC_CLUSTER_DIR}/backup
BUCKET_NAME="${USER}-hosted-${MGMT_REGION}"
# DNS
AWS_ZONE_ID="Z026552815SS3YPH9H6MG"
EXTERNAL_DNS_DOMAIN="guest.jpdv.aws.kerbeross.com"
Save the script to your local file system.
Run the script by entering the following command:
source <env_file>
where:
env_file
is the name of the file where you saved the script.The migration script is maintained at the following repository: https://github.com/openshift/hypershift/blob/main/contrib/migration/migrate-hcp.sh.