About migrating from OKD 3 to 4 | Migrating from version 3 to 4

About
- Welcome
- Kubernetes overview
What's new?
- New features and enhancements
- Deprecated features
Architecture
- Architecture overview
- Product architecture
- Installation and update
- Control plane architecture
- Understanding OKD development
- Fedora CoreOS
Installing
- Installation overview
- Selecting an installation method and preparing a cluster
- Mirroring images for a disconnected installation
- Installing on AWS
- Installing on Azure
- Installing on GCP
- Installing on bare metal
- Deploying installer-provisioned clusters on bare metal
- Installing on OpenStack
- Installing on oVirt
- Installing on vSphere
- Installing on VMC
- Installing on any platform
  - Installing a cluster on any platform
- Installation configuration
  - Customizing nodes
  - Configuring your firewall
- Validating an installation
- Troubleshooting installation issues
Post-installation configuration
- Post-installation configuration overview
- Configuring a private cluster
- Machine configuration tasks
- Cluster tasks
- Node tasks
- Network configuration
- Storage configuration
- Preparing for users
- Configuring alert notifications
- Configuring additional devices in an IBM Z or LinuxONE environment
Updating clusters
- Understanding OpenShift updates
- Updating clusters overview
- Understanding upgrade channels
- Preparing to perform an EUS-to-EUS update
- Updating a cluster using the web console
- Updating a cluster using the CLI
- Performing update using canary rollout strategy
Support
- Support overview
- Managing your cluster resources
- Getting support
- Remote health monitoring with connected clusters
- Gathering data about your cluster
- Summarizing cluster specifications
- Troubleshooting
Web console
- Web console overview
- Accessing the web console
- Viewing cluster information
- Configuring the web console
- Customizing the web console
- Disabling the web console
- Creating quick start tutorials
CLI tools
- CLI tools overview
- OpenShift CLI (oc)
- Developer CLI (odo)
- Knative CLI (kn) for use with OpenShift Serverless
- opm CLI
- Operator SDK
  - Installing the Operator SDK CLI
  - Operator SDK CLI reference
Security and compliance
- Security and compliance overview
- Container security
- Configuring certificates
- Certificate types and descriptions
- Compliance Operator
- File Integrity Operator
- Viewing audit logs
- Configuring the audit log policy
- Configuring TLS security profiles
- Configuring seccomp profiles
- Allowing JavaScript-based access to the API server from additional hosts
- Encrypting etcd data
- Scanning pods for vulnerabilities
Authentication and authorization
- Authentication and authorization overview
- Understanding authentication
- Configuring the internal OAuth server
- Configuring OAuth clients
- Managing user-owned OAuth access tokens
- Understanding identity provider configuration
- Configuring identity providers
- Using RBAC to define and apply permissions
- Removing the kubeadmin user
- Understanding and creating service accounts
- Using service accounts in applications
- Using a service account as an OAuth client
- Scoping tokens
- Using bound service account tokens
- Managing security context constraints
- Impersonating the system:admin user
- Syncing LDAP groups
- Managing cloud provider credentials
Networking
- Understanding networking
- Accessing hosts
- Networking Operators overview
- Understanding the Cluster Network Operator
- Understanding the DNS Operator
- Understanding the Ingress Operator
- Verifying connectivity to an endpoint
- Configuring the node port service range
- Configuring IP failover
- Using SCTP
- Configuring PTP hardware
- Network policy
  - About network policy
  - Logging network policy
  - Creating a network policy
  - Viewing a network policy
  - Editing a network policy
  - Deleting a network policy
  - Defining a default network policy for projects
  - Configuring multitenant network policy
- Multiple networks
  - Understanding multiple networks
  - Configuring an additional network
  - About virtual routing and forwarding
  - Configuring multi-network policy
  - Attaching a pod to an additional network
  - Removing a pod from an additional network
  - Editing an additional network
  - Removing an additional network
  - Assigning a secondary network to a VRF
- Hardware networks
  - About Single Root I/O Virtualization (SR-IOV) hardware networks
  - Installing the SR-IOV Operator
  - Configuring the SR-IOV Operator
  - Configuring an SR-IOV network device
  - Configuring an SR-IOV Ethernet network attachment
  - Configuring an SR-IOV InfiniBand network attachment
  - Adding a pod to an SR-IOV network
  - Using high performance multicast
  - Using DPDK and RDMA
  - Uninstalling the SR-IOV Operator
- OpenShift SDN default CNI network provider
  - About the OpenShift SDN default CNI network provider
  - Configuring egress IPs for a project
  - Configuring an egress firewall for a project
  - Viewing an egress firewall for a project
  - Editing an egress firewall for a project
  - Removing an egress firewall from a project
  - Considerations for the use of an egress router pod
  - Deploying an egress router pod in redirect mode
  - Deploying an egress router pod in HTTP proxy mode
  - Deploying an egress router pod in DNS proxy mode
  - Configuring an egress router pod destination list from a config map
  - Enabling multicast for a project
  - Disabling multicast for a project
  - Configuring multitenant isolation
  - Configuring kube-proxy
- OVN-Kubernetes default CNI network provider
  - About the OVN-Kubernetes network provider
  - Migrating from the OpenShift SDN cluster network provider
  - Rolling back to the OpenShift SDN cluster network provider
  - Converting to IPv4/IPv6 dual stack networking
  - IPsec encryption configuration
  - Configuring an egress firewall for a project
  - Viewing an egress firewall for a project
  - Editing an egress firewall for a project
  - Removing an egress firewall from a project
  - Configuring an egress IP address
  - Assigning an egress IP address
  - Considerations for the use of an egress router pod
  - Deploying an egress router pod in redirect mode
  - Enabling multicast for a project
  - Disabling multicast for a project
  - Tracking network flows
  - Configuring hybrid networking
- Configuring Routes
  - Route configuration
  - Secured routes
- Configuring ingress cluster traffic
  - Overview
  - Configuring ExternalIPs for services
  - Configuring ingress cluster traffic using an Ingress Controller
  - Configuring ingress cluster traffic using a load balancer
  - Configuring ingress cluster traffic on AWS using a Network Load Balancer
  - Configuring ingress cluster traffic using a service external IP
  - Configuring ingress cluster traffic using a NodePort
- Kubernetes NMState
  - About the Kubernetes NMState Operator
  - Observing node network state
  - Updating node network configuration
  - Troubleshooting node network configuration
- Configuring the cluster-wide proxy
- Configuring a custom PKI
- Load balancing on OpenStack
- Associating secondary interfaces metrics to network attachments
Storage
- Storage overview
- Understanding ephemeral storage
- Understanding persistent storage
- Configuring persistent storage
- Using Container Storage Interface (CSI)
- Expanding persistent volumes
- Dynamic provisioning
Registry
- Registry overview
- Image Registry Operator in OKD
- Setting up and configuring the registry
- Accessing the registry
- Exposing the registry
Operators
- Operators overview
- Understanding Operators
- User tasks
  - Creating applications from installed Operators
  - Installing Operators in your namespace
- Administrator tasks
- Developing Operators
- Cluster Operators reference
CI/CD
- CI/CD overview
- Builds
Images
- Overview of images
- Configuring the Cluster Samples Operator
- Using the Cluster Samples Operator with an alternate registry
- Creating images
- Managing images
- Managing image streams
- Using image streams with Kubernetes resources
- Triggering updates on image stream changes
- Image configuration resources
- Using templates
- Using Ruby on Rails
- Using images
Building Applications
- Building Applications overview
- Projects
- Creating Applications
- Viewing application composition using the Topology view
- Working with Helm charts
- Deployments
- Quotas
  - Resource quotas per project
  - Resource quotas across multiple projects
- Using config maps with applications
- Monitoring project and application metrics using the Developer perspective
- Monitoring application health
- Editing applications
- Pruning objects to reclaim resources
- Idling applications
- Deleting applications
- Using the Red Hat Marketplace
Machine management
- Overview of machine management
- Creating machine sets
- Manually scaling a machine set
- Modifying a machine set
- Deleting a machine
- Applying autoscaling to a cluster
- Creating infrastructure machine sets
- User-provisioned infrastructure
- Deploying machine health checks
Nodes
- Overview of nodes
- Working with pods
- Controlling pod placement onto nodes (scheduling)
- Using Jobs and DaemonSets
  - Running background tasks on nodes automatically with daemonsets
  - Running tasks in pods using jobs
- Working with nodes
- Working with containers
- Working with clusters
Windows Container Support for OpenShift
- Red Hat OpenShift support for Windows Containers overview
- Red Hat OpenShift support for Windows Containers release notes
- Understanding Windows container workloads
- Enabling Windows container workloads
- Creating Windows MachineSet objects
- Scheduling Windows container workloads
- Windows node upgrades
- Using Bring-Your-Own-Host Windows instances as nodes
- Removing Windows nodes
- Disabling Windows container workloads
Logging
- Release notes
- About Logging
- Installing Logging
- Configuring your Logging deployment
- Viewing logs for a specific resource
- Viewing cluster logs in Kibana
- Forwarding logs to third party systems
- Enabling JSON logging
- Collecting and storing Kubernetes events
- Updating Logging
- Viewing cluster dashboards
- Troubleshooting Logging
- Uninstalling Logging
- Exported fields
Monitoring
- Monitoring overview
- Configuring the monitoring stack
- Enabling monitoring for user-defined projects
- Managing metrics
- Managing alerts
- Reviewing monitoring dashboards
- Accessing third-party UIs
- Troubleshooting monitoring issues
Scalability and performance
- Recommended host practices
- Recommended cluster scaling practices
- Using the Node Tuning Operator
- Using Cluster Loader
- Using CPU Manager
- Using Topology Manager
- Scaling the Cluster Monitoring Operator
- The Node Feature Discovery Operator
- The Driver Toolkit
- Planning your environment according to object maximums
- Optimizing storage
- Optimizing routing
- Optimizing networking
- Managing bare metal hosts
- What huge pages do and how they are consumed by apps
- Performing latency tests for platform verification
- Creating a performance profile
Backup and restore
- Overview of backup and restore operations
- Shutting down a cluster gracefully
- Restarting a cluster gracefully
- Application backup and restore
- Control plane backup and restore
Migrating from version 3 to 4
- Migrating from version 3 to 4 overview
- About migrating from OKD 3 to 4
- Differences between OKD 3 and 4
- Network considerations
- About MTC
- Installing MTC
- Installing MTC in a restricted network environment
- Upgrading MTC
- Premigration checklists
- Migrating your applications
- Advanced migration options
- Troubleshooting
Migration Toolkit for Containers
- About MTC
- MTC release notes
- Installing MTC
- Installing MTC in a restricted network environment
- Upgrading MTC
- Premigration checklists
- Network considerations
- Migrating your applications
- Advanced migration options
- Troubleshooting
API reference
- Understanding API tiers
- API compatibility guidelines
- Editing kubelet log level verbosity and gathering logs
- API list
- Common object reference
  - Index
- Authorization APIs
  - About Authorization APIs
  - LocalResourceAccessReview [authorization.openshift.io/v1]
  - LocalSubjectAccessReview [authorization.openshift.io/v1]
  - ResourceAccessReview [authorization.openshift.io/v1]
  - SelfSubjectRulesReview [authorization.openshift.io/v1]
  - SubjectAccessReview [authorization.openshift.io/v1]
  - SubjectRulesReview [authorization.openshift.io/v1]
  - TokenReview [authentication.k8s.io/v1]
  - LocalSubjectAccessReview [authorization.k8s.io/v1]
  - SelfSubjectAccessReview [authorization.k8s.io/v1]
  - SelfSubjectRulesReview [authorization.k8s.io/v1]
  - SubjectAccessReview [authorization.k8s.io/v1]
- Autoscale APIs
  - About Autoscale APIs
  - ClusterAutoscaler [autoscaling.openshift.io/v1]
  - MachineAutoscaler [autoscaling.openshift.io/v1beta1]
  - HorizontalPodAutoscaler [autoscaling/v1]
- Config APIs
  - About Config APIs
  - APIServer [config.openshift.io/v1]
  - Authentication [config.openshift.io/v1]
  - Build [config.openshift.io/v1]
  - ClusterOperator [config.openshift.io/v1]
  - ClusterVersion [config.openshift.io/v1]
  - Console [config.openshift.io/v1]
  - DNS [config.openshift.io/v1]
  - FeatureGate [config.openshift.io/v1]
  - HelmChartRepository [helm.openshift.io/v1beta1]
  - Image [config.openshift.io/v1]
  - Infrastructure [config.openshift.io/v1]
  - Ingress [config.openshift.io/v1]
  - Network [config.openshift.io/v1]
  - OAuth [config.openshift.io/v1]
  - OperatorHub [config.openshift.io/v1]
  - Project [config.openshift.io/v1]
  - Proxy [config.openshift.io/v1]
  - Scheduler [config.openshift.io/v1]
- Console APIs
  - About Console APIs
  - ConsoleCLIDownload [console.openshift.io/v1]
  - ConsoleExternalLogLink [console.openshift.io/v1]
  - ConsoleLink [console.openshift.io/v1]
  - ConsoleNotification [console.openshift.io/v1]
  - ConsolePlugin [console.openshift.io/v1alpha1]
  - ConsoleQuickStart [console.openshift.io/v1]
  - ConsoleYAMLSample [console.openshift.io/v1]
- Extension APIs
  - About Extension APIs
  - APIService [apiregistration.k8s.io/v1]
  - CustomResourceDefinition [apiextensions.k8s.io/v1]
  - MutatingWebhookConfiguration [admissionregistration.k8s.io/v1]
  - ValidatingWebhookConfiguration [admissionregistration.k8s.io/v1]
- Image APIs
  - About Image APIs
  - Image [image.openshift.io/v1]
  - ImageSignature [image.openshift.io/v1]
  - ImageStreamImage [image.openshift.io/v1]
  - ImageStreamImport [image.openshift.io/v1]
  - ImageStreamMapping [image.openshift.io/v1]
  - ImageStream [image.openshift.io/v1]
  - ImageStreamTag [image.openshift.io/v1]
  - ImageTag [image.openshift.io/v1]
- Machine APIs
  - About Machine APIs
  - ContainerRuntimeConfig [machineconfiguration.openshift.io/v1]
  - ControllerConfig [machineconfiguration.openshift.io/v1]
  - KubeletConfig [machineconfiguration.openshift.io/v1]
  - MachineConfigPool [machineconfiguration.openshift.io/v1]
  - MachineConfig [machineconfiguration.openshift.io/v1]
  - MachineHealthCheck [machine.openshift.io/v1beta1]
  - Machine [machine.openshift.io/v1beta1]
  - MachineSet [machine.openshift.io/v1beta1]
- Metadata APIs
  - About Metadata APIs
  - APIRequestCount [apiserver.openshift.io/v1]
  - Binding [core/v1]
  - ComponentStatus [core/v1]
  - ConfigMap [core/v1]
  - ControllerRevision [apps/v1]
  - Event [events.k8s.io/v1]
  - Event [core/v1]
  - Lease [coordination.k8s.io/v1]
  - Namespace [core/v1]
- Monitoring APIs
  - About Monitoring APIs
  - Alertmanager [monitoring.coreos.com/v1]
  - AlertmanagerConfig [monitoring.coreos.com/v1alpha1]
  - PodMonitor [monitoring.coreos.com/v1]
  - Probe [monitoring.coreos.com/v1]
  - Prometheus [monitoring.coreos.com/v1]
  - PrometheusRule [monitoring.coreos.com/v1]
  - ServiceMonitor [monitoring.coreos.com/v1]
  - ThanosRuler [monitoring.coreos.com/v1]
- Network APIs
  - About Network APIs
  - ClusterNetwork [network.openshift.io/v1]
  - Endpoints [core/v1]
  - EndpointSlice [discovery.k8s.io/v1]
  - EgressNetworkPolicy [network.openshift.io/v1]
  - EgressRouter [network.operator.openshift.io/v1]
  - HostSubnet [network.openshift.io/v1]
  - Ingress [networking.k8s.io/v1]
  - IngressClass [networking.k8s.io/v1]
  - IPPool [whereabouts.cni.cncf.io/v1alpha1]
  - NetNamespace [network.openshift.io/v1]
  - NetworkAttachmentDefinition [k8s.cni.cncf.io/v1]
  - NetworkPolicy [networking.k8s.io/v1]
  - PodNetworkConnectivityCheck [controlplane.operator.openshift.io/v1alpha1]
  - Route [route.openshift.io/v1]
  - Service [core/v1]
- Node APIs
  - About Node APIs
  - Node [core/v1]
  - Profile [tuned.openshift.io/v1]
  - RuntimeClass [node.k8s.io/v1]
  - Tuned [tuned.openshift.io/v1]
- OAuth APIs
  - About OAuth APIs
  - OAuthAccessToken [oauth.openshift.io/v1]
  - OAuthAuthorizeToken [oauth.openshift.io/v1]
  - OAuthClientAuthorization [oauth.openshift.io/v1]
  - OAuthClient [oauth.openshift.io/v1]
  - UserOAuthAccessToken [oauth.openshift.io/v1]
- Operator APIs
  - About Operator APIs
  - Authentication [operator.openshift.io/v1]
  - CloudCredential [operator.openshift.io/v1]
  - ClusterCSIDriver [operator.openshift.io/v1]
  - Console [operator.openshift.io/v1]
  - Config [operator.openshift.io/v1]
  - Config [imageregistry.operator.openshift.io/v1]
  - Config [samples.operator.openshift.io/v1]
  - CSISnapshotController [operator.openshift.io/v1]
  - DNS [operator.openshift.io/v1]
  - DNSRecord [ingress.operator.openshift.io/v1]
  - Etcd [operator.openshift.io/v1]
  - ImageContentSourcePolicy [operator.openshift.io/v1alpha1]
  - ImagePruner [imageregistry.operator.openshift.io/v1]
  - IngressController [operator.openshift.io/v1]
  - KubeAPIServer [operator.openshift.io/v1]
  - KubeControllerManager [operator.openshift.io/v1]
  - KubeScheduler [operator.openshift.io/v1]
  - KubeStorageVersionMigrator [operator.openshift.io/v1]
  - Network [operator.openshift.io/v1]
  - OpenShiftAPIServer [operator.openshift.io/v1]
  - OpenShiftControllerManager [operator.openshift.io/v1]
  - OperatorPKI [network.operator.openshift.io/v1]
  - ServiceCA [operator.openshift.io/v1]
  - Storage [operator.openshift.io/v1]
- OperatorHub APIs
  - About OperatorHub APIs
  - CatalogSource [operators.coreos.com/v1alpha1]
  - ClusterServiceVersion [operators.coreos.com/v1alpha1]
  - InstallPlan [operators.coreos.com/v1alpha1]
  - Operator [operators.coreos.com/v1]
  - OperatorCondition [operators.coreos.com/v1]
  - OperatorGroup [operators.coreos.com/v1]
  - PackageManifest [packages.operators.coreos.com/v1]
  - Subscription [operators.coreos.com/v1alpha1]
- Policy APIs
  - About Policy APIs
  - PodDisruptionBudget [policy/v1]
- Project APIs
  - About Project APIs
  - Project [project.openshift.io/v1]
  - ProjectRequest [project.openshift.io/v1]
- Provisioning APIs
  - About Provisioning APIs
  - BareMetalHost [metal3.io/v1alpha1]
  - Provisioning [metal3.io/v1alpha1]
- RBAC APIs
  - About RBAC APIs
  - ClusterRoleBinding [rbac.authorization.k8s.io/v1]
  - ClusterRole [rbac.authorization.k8s.io/v1]
  - RoleBinding [rbac.authorization.k8s.io/v1]
  - Role [rbac.authorization.k8s.io/v1]
- Role APIs
  - About Role APIs
  - ClusterRoleBinding [authorization.openshift.io/v1]
  - ClusterRole [authorization.openshift.io/v1]
  - RoleBindingRestriction [authorization.openshift.io/v1]
  - RoleBinding [authorization.openshift.io/v1]
  - Role [authorization.openshift.io/v1]
- Schedule and quota APIs
  - About Schedule and quota APIs
  - AppliedClusterResourceQuota [quota.openshift.io/v1]
  - ClusterResourceQuota [quota.openshift.io/v1]
  - FlowSchema [flowcontrol.apiserver.k8s.io/v1beta1]
  - LimitRange [core/v1]
  - PriorityClass [scheduling.k8s.io/v1]
  - PriorityLevelConfiguration [flowcontrol.apiserver.k8s.io/v1beta1]
  - ResourceQuota [core/v1]
- Security APIs
  - About Security APIs
  - CertificateSigningRequest [certificates.k8s.io/v1]
  - CredentialsRequest [cloudcredential.openshift.io/v1]
  - PodSecurityPolicyReview [security.openshift.io/v1]
  - PodSecurityPolicySelfSubjectReview [security.openshift.io/v1]
  - PodSecurityPolicySubjectReview [security.openshift.io/v1]
  - RangeAllocation [security.openshift.io/v1]
  - Secret [core/v1]
  - SecurityContextConstraints [security.openshift.io/v1]
  - ServiceAccount [core/v1]
- Storage APIs
  - About Storage APIs
  - CSIDriver [storage.k8s.io/v1]
  - CSINode [storage.k8s.io/v1]
  - CSIStorageCapacity [storage.k8s.io/v1beta1]
  - PersistentVolumeClaim [core/v1]
  - StorageClass [storage.k8s.io/v1]
  - StorageState [migration.k8s.io/v1alpha1]
  - StorageVersionMigration [migration.k8s.io/v1alpha1]
  - VolumeAttachment [storage.k8s.io/v1]
  - VolumeSnapshot [snapshot.storage.k8s.io/v1]
  - VolumeSnapshotClass [snapshot.storage.k8s.io/v1]
  - VolumeSnapshotContent [snapshot.storage.k8s.io/v1]
- Template APIs
  - About Template APIs
  - BrokerTemplateInstance [template.openshift.io/v1]
  - PodTemplate [core/v1]
  - Template [template.openshift.io/v1]
  - TemplateInstance [template.openshift.io/v1]
- User and group APIs
  - About User and group APIs
  - Group [user.openshift.io/v1]
  - Identity [user.openshift.io/v1]
  - UserIdentityMapping [user.openshift.io/v1]
  - User [user.openshift.io/v1]
- Workloads APIs
  - About Workloads APIs
  - BuildConfig [build.openshift.io/v1]
  - Build [build.openshift.io/v1]
  - CronJob [batch/v1]
  - DaemonSet [apps/v1]
  - Deployment [apps/v1]
  - DeploymentConfig [apps.openshift.io/v1]
  - Job [batch/v1]
  - Pod [core/v1]
  - ReplicationController [core/v1]
  - PersistentVolume [core/v1]
  - ReplicaSet [apps/v1]
  - StatefulSet [apps/v1]

OKD 4 contains new technologies and functionality that result in a cluster that is self-managing, flexible, and automated. OKD 4 clusters are deployed and managed very differently from OKD 3.

The most effective way to migrate from OKD 3 to 4 is by using a CI/CD pipeline to automate deployments in an application lifecycle management framework.

If you do not have a CI/CD pipeline or if you are migrating stateful applications, you can use the Migration Toolkit for Containers (MTC) to migrate your application workloads.

To successfully transition to OKD 4, review the following information:

Differences between OKD 3 and 4

Architecture
Installation and upgrade
Storage, network, logging, security, and monitoring considerations

About the Migration Toolkit for Containers

Workflow
File system and snapshot copy methods for persistent volumes (PVs)
Direct volume migration
Direct image migration

Advanced migration options

Automating your migration with migration hooks
Using the MTC API
Excluding resources from a migration plan
Configuring the MigrationController custom resource for large-scale migrations
Enabling automatic PV resizing for direct volume migration
Enabling cached Kubernetes clients for improved performance

For new features and enhancements, technical changes, and known issues, see the MTC release notes.