csi driver openshift for OpenShift Container Storage and Deployment

CSI driver for OpenShift is a crucial component for managing storage and deployment in OpenShift Container Storage.

The CSI driver for OpenShift allows for the integration of external storage systems into OpenShift, providing a scalable and flexible storage solution.

This integration enables users to manage storage resources more efficiently, and it supports a wide range of storage systems, including block, file, and object storage.

CSI driver for OpenShift is designed to work seamlessly with OpenShift Container Storage, providing a robust and reliable storage solution for containerized applications.

A CSI driver is typically shipped as a container image, which is not aware it's running on OpenShift Container Platform. This image is used to connect to storage backends.

To use CSI storage backends, cluster administrators deploy multiple components that serve as a bridge between the storage driver and OpenShift Container Platform. This bridge is necessary because the CSI driver is not aware of the platform.

Several CSI drivers can be run for different storage backends. Each driver requires its own external controllers deployment and daemon set with the driver and CSI registrar.

CSI drivers are connected to the platform using external CSI controllers, which deploy one or more pods with various containers, including an attacher container, provisioner container, and CSI driver container.

The CSI driver communicates with the attacher and provisioner containers using UNIX Domain Sockets, ensuring that no CSI communication leaves the pod. The CSI driver is not accessible from outside the pod.

Here's a breakdown of the components involved in the CSI architecture:

These components work together to enable dynamic provisioning for persistent storage, allowing developers to specify a storage class in their PVC and receive a persistent volume belonging to that storage class.

A DaemonSet in OpenShift Container Platform is a way to run a pod on every node in the cluster. It's used to deploy the CSI driver, which allows OpenShift to mount storage provided by the CSI driver to the node.

The CSI driver DaemonSet runs a pod on every node that contains the CSI driver registrar and the CSI driver itself. The CSI driver registrar registers the CSI driver into the openshift-node service running on the node.

You can deploy a CSI driver using a DaemonSet, and it's a good practice to use a service account with the necessary permissions to run the CSI driver. The DaemonSet should have as few credentials to the storage backend as possible.

A Deployment in OpenShift is used to manage the rollout of new versions of an application. In the context of the CSI driver, a Deployment is used to manage the rollout of the CSI driver.

Here's a summary of the CSI driver Deployment:

Here's an example of a DaemonSet used to deploy the CSI driver:

This DaemonSet uses the CSI driver registrar and the cinder-driver container to deploy the CSI driver on every node in the cluster.

Dynamic provisioning of persistent storage in OpenShift Container Platform depends on the capabilities of the CSI driver and underlying storage backend. The provider of the CSI driver should document how to create a StorageClass in OpenShift Container Platform and the parameters available for configuration.

You can deploy a StorageClass to enable dynamic provisioning, such as the OpenStack Cinder example. This example creates a new default storage class that ensures all PVCs that do not require any special storage class are provisioned by the installed CSI driver.

To create a default storage class, you can use the following command: `oc create -f - << EOF`. This command creates a new StorageClass with the specified name, annotations, and parameters.

Here are the key parameters for creating a StorageClass:

OpenShift Data Foundation offers highly available, dynamic, and stateful container-native storage. It lets you perform on-demand provisioning and de-provisioning of storage directly from the OpenShift administrator console.

OpenShift provides two types of ephemeral storage: Root ephemeral storage and Runtime ephemeral storage. Root ephemeral storage is a partition on the node that houses the kubelet root directory and the /var/log/, while Runtime ephemeral storage is a partition that can optionally be added, optimized for storing container layers.

The lifecycle of Persistent Volumes in OpenShift Container Platform includes three stages: Administrators provision storage, Binding PV to a claim, and Pods access volumes. This process ensures that Persistent Volumes are properly managed and accessible to pods.

To use the CSI driver in OpenShift Container Platform, you need to deploy the CSI driver and create a storage class for dynamic provisioning.

Once the CSI driver is deployed and a storage class is created, you can use it to install a MySQL template without any changes to the template. This can be done by running the command `oc new-app mysql-persistent`.

To verify that the CSI driver is working correctly, you can check the status of the Persistent Volume Claim (PVC) created by the MySQL template. The PVC should be in a "Bound" state, indicating that it has been successfully provisioned.

To use OpenShift Container Platform with the CSI driver, you'll need to have the CSI driver deployed and a storage class created for dynamic provisioning.

The CSI driver has been deployed, and a storage class has been created for dynamic provisioning. This is a crucial step before you can start using the CSI driver.

Once you've completed this step, you can install a default MySQL template without making any changes to the template.

The example of installing a default MySQL template without any changes to the template is as follows:

The resulting PVC will be bound to a dynamic volume, which can be seen in the output of the `#oc get pvc` command.

Here's an example of the output you might see:

The Container Interface is a crucial component in the OpenShift Container Platform. It enables the platform to consume information from storage backend sources.

The Container Storage Interface (CSI) is a key technology that makes this possible. CSI allows OpenShift to interact with various storage systems.

OpenShift Container Platform can utilize information from storage backend sources thanks to the CSI. This is a significant advantage for users who need to manage large amounts of data.

A diagram showing the main components running inside OpenShift pods illustrates the CSI's role. The diagram is sourced from OpenShift.

Operators and Management are a crucial part of deploying and managing applications in Kubernetes, especially in Red Hat OpenShift clusters.

The BeeGFS CSI driver operator, like all Kubernetes operators, consists of two components: a custom controller and a Custom Resource.

A custom controller is capable of deploying, updating, and deleting objects such as Stateful Sets, Daemon Sets, Service Accounts, Roles, and Role Bindings.

The Custom Resource allows for declarative configuration of the driver as a whole, making it easier for administrators to manage the driver.

With the Custom Resource, administrators can modify the configuration and expect the custom controller to deploy, update, or delete the necessary objects.

In an OpenShift 4.8 cluster, installing the BeeGFS CSI driver operator is as simple as a few clicks through the web console.

OLM (Operator Lifecycle Manager) extends Kubernetes to provide a declarative way to install, manage, and upgrade Operators on a cluster.

OLM automatically installs the operator and its Custom Resources on a cluster, and can optionally upgrade the operator and its owned objects when a new version is released.

Here is a summary of the Kubernetes objects required to run the BeeGFS CSI driver correctly: