Welcome to the official OKD 4 documentation, where you can find information to help you learn about OKD and start exploring its features.
To navigate the OKD 4 documentation, you can either
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As someone setting out to install an OKD 4 cluster, this documentation helps you:
OKD installation overview: You can install OKD on installer-provisioned or user-provisioned infrastructure. The OKD installation program provides the flexibility to deploy OKD on a range of different platforms.
Install a cluster on AWS: You have the most installation options when you deploy a cluster on Amazon Web Services (AWS). You can deploy clusters with default settings or custom AWS settings. You can also deploy a cluster on AWS infrastructure that you provisioned yourself. You can modify the provided AWS CloudFormation templates to meet your needs.
Install a cluster on Azure: You can deploy clusters with default settings, custom Azure settings, or custom networking settings in Microsoft Azure. You can also provision OKD into an Azure Virtual Network or use Azure Resource Manager Templates to provision your own infrastructure.
Install a cluster on GCP: You can deploy clusters with default settings or custom GCP settings on Google Cloud Platform (GCP). You can also perform a GCP installation where you provision your own infrastructure.
Install a cluster on VMware vSphere: You can install OKD on supported versions of vSphere.
Install a cluster on bare metal: If none of the available platform and cloud providers meet your needs, you can install OKD on bare metal.
Install an installer-provisioned cluster on bare metal: You can install OKD on bare metal with an installer-provisioned architecture.
Create Fedora CoreOS (FCOS) machines on bare metal: You can install FCOS machines using ISO or PXE in a fully live environment and configure them with kernel arguments, Ignition configs, or the
Install a cluster on Red Hat OpenStack Platform (RHOSP): You can install a cluster on RHOSP with customizations.
Install a cluster in a restricted network: If your cluster that uses user-provisioned infrastructure on AWS, GCP, vSphere, or bare metal does not have full access to the internet, you can mirror the OKD installation images and install a cluster in a restricted network.
Install a private cluster: If your cluster does not require external internet access, you can install a private cluster on AWS, Azure, or GCP. Internet access is still required to access the cloud APIs and installation media.
Check installation logs: Access installation logs to evaluate issues that occur during OKD 4 installation.
Access OKD: Use credentials output at the end of the installation process to log in to the OKD cluster from the command line or web console.
Install Red Hat OpenShift Container Storage: You can install Red Hat OpenShift Container Storage as an Operator to provide highly integrated and simplified persistent storage management for containers.
Ultimately, OKD is a platform for developing and deploying containerized applications. As an application developer, OKD documentation helps you:
Understand OKD development: Learn the different types of containerized applications, from simple containers to advanced Kubernetes deployments and Operators.
Work with projects: Create projects from the web console or CLI to organize and share the software you develop.
Work with applications: Use the Developer perspective in the OKD web console to easily create and deploy applications. Use the Topology view to visually interact with your applications, monitor status, connect and group components, and modify your code base.
Use the developer CLI tool (odo): The odo CLI tool lets developers create single or multi-component applications easily and automates deployment, build, and service route configurations. It abstracts complex Kubernetes and OKD concepts, allowing developers to focus on developing their applications.
Create CI/CD Pipelines: Pipelines are serverless, cloud-native, continuous integration and continuous deployment systems that run in isolated containers. They use standard Tekton custom resources to automate deployments and are designed for decentralized teams that work on microservices-based architecture.
Deploy Helm charts: Helm 3 is a package manager that helps developers define, install, and update application packages on Kubernetes. A Helm chart is a packaging format that describes an application that can be deployed using the Helm CLI.
Understand Operators: Operators are the preferred method for creating on-cluster applications for OKD 4. Learn about the Operator Framework and how to deploy applications using installed Operators into your projects.
Understand image builds: Choose from different build strategies (Docker, S2I, custom, and pipeline) that can include different kinds of source materials (from places like Git repositories, local binary inputs, and external artifacts). Then, follow examples of build types from basic builds to advanced builds.
Create container images: A container image is the most basic building block in OKD (and Kubernetes) applications. Defining image streams lets you gather multiple versions of an image in one place as you continue its development. S2I containers let you insert your source code into a base container that is set up to run code of a particular type (such as Ruby, Node.js, or Python).
Create deployments: Use
DeploymentConfig objects to exert fine-grained management over applications.
Use the Workloads page or
oc CLI to manage deployments. Learn rolling, recreate, and custom deployment strategies.
Create templates: Use existing templates or create your own templates that describe how an application is built or deployed. A template can combine images with descriptions, parameters, replicas, exposed ports and other content that defines how an application can be run or built.
Develop Operators: Operators are the preferred method for creating on-cluster applications for OKD 4. Learn the workflow for building, testing, and deploying Operators. Then create your own Operators based on Ansible or Helm, or configure built-in Prometheus monitoring using the Operator SDK.
REST API reference: Lists OKD application programming interface endpoints.
Ongoing tasks on your OKD 4 cluster include various activities for managing machines, providing services to users, and following monitoring and logging features that watch over the cluster. As a cluster administrator, this documentation helps you:
Manage container registries: Each OKD cluster includes a built-in container registry for storing its images. You can also configure a separate Red Hat Quay registry to use with OKD. The Quay.io web site provides a public container registry that stores OKD containers and Operators.
Manage users and groups: Add users and groups that have different levels of permissions to use or modify clusters.
Manage authentication: Learn how user, group, and API authentication works in OKD. OKD supports multiple identity providers, including HTPasswd, Keystone, LDAP, basic authentication, request header, GitHub, GitLab, Google, and OpenID.
Manage ingress, API server, and service certificates: OKD creates certificates by default for the Ingress Operator, the API server, and for services needed by complex middleware applications that require encryption. At some point, you might need to change, add, or rotate these certificates.
Manage networking: Networking in OKD is managed by the Cluster Network Operator (CNO). The CNO uses iptables rules in kube-proxy to direct traffic between nodes and pods running on those nodes. The Multus Container Network Interface adds the capability to attach multiple network interfaces to a pod. Using network policy features, you can isolate your pods or permit selected traffic.
Manage storage: OKD allows cluster administrators to configure persistent storage using Red Hat OpenShift Container Storage, AWS Elastic Block Store, NFS, iSCSI, Container Storage Interface (CSI), and more. As needed, you can expand persistent volumes, configure dynamic provisioning, and use CSI to configure, clone, and use snapshots of persistent storage.
Manage Operators: Lists of Red Hat, ISV, and community Operators can be reviewed by cluster administrators and installed on their clusters. Once installed, you can run, upgrade, back up or otherwise manage the Operator on your cluster.
Use custom resource definitions (CRDs) to modify the cluster: Cluster features that are implemented with Operators, can be modified with CRDs. Learn to create a CRD and manage resources from CRDs.
Prune and reclaim resources: You can reclaim space by pruning unneeded Operators, groups, deployments, builds, images, registries, and cron jobs.
Update a cluster: To upgrade your OKD to a later version, use the Cluster Version Operator (CVO). If an update is available from the Container Platform update service, you apply that cluster update from either the web console or the CLI.
Work with OpenShift Logging: Learn about OpenShift Logging and configure different OpenShift Logging types, such as Elasticsearch, Fluentd, Kibana, and Curator.
Monitor clusters: Learn to configure the monitoring stack. Once your monitoring is configured, use the Web UI to access monitoring dashboards. In addition to infrastructure metrics, you can also scrape and view metrics for your own services.
Remote health monitoring: OKD collects anonymized aggregated information about your cluster and reports it to Red Hat via Telemetry and the Insights Operator. This information allows Red Hat to improve OKD and to react to issues that impact customers more quickly. You can view the data collected by remote health monitoring.