Sandboxed Containers Support for OpenShift

OpenShift Container Platform 4.8

OpenShift sandboxed containers guide

Red Hat OpenShift Documentation Team

Abstract

OpenShift sandboxed containers support for OpenShift Container Platform provides users with built-in support for running Kata Containers as an additional optional runtime.

Chapter 1. {sandboxed-containers-first} 1.0 release notes

1.1. About this release

These release notes track the development of OpenShift sandboxed containers in Red Hat OpenShift Container Platform.

This product is currently in Technology Preview. OpenShift sandboxed containers is not intended for production use. For more information, see the Red Hat Customer Portal support scope for features in Technology Preview.

1.2. New features and enhancements

1.2.1. OpenShift sandboxed containers support on OpenShift Container Platform (Technology Preview)

OpenShift sandboxed containers 1.0.0 Technology Preview release introduces built-in support for running Kata Containers as an additional runtime. OpenShift sandboxed containers enables users to choose Kata Containers as an additional runtime to provide additional isolation for their workloads. The OpenShift sandboxed containers Operator automates the tasks of installing, removing, and updating Kata Containers. It allows for tracking the state of those tasks by describing the KataConfig custom resource.

OpenShift sandboxed containers are only supported on bare metal. Red Hat Enterprise Linux CoreOS (RHCOS) is the only supported operating system for OpenShift sandboxed containers 1.0.0. Disconnected environments are not supported in OpenShift Container Platform 4.8.

For more information, see Understanding OpenShift sandboxed containers

1.3. Known issues

  • If you are using OpenShift sandboxed containers, you cannot use the hostPath volume in a OpenShift Container Platform cluster to mount a file or directory from the host node’s file system into your pod. As an alternative, you can use local persistent volumes. See Persistent storage using local volumes for more information. (BZ#1904609)

  • If you are running Fedora on OpenShift sandboxed containers, you need a workaround to install some packages. Some packages, like iputils, require file access permission changes that OpenShift Container Platform does not grant to containers by default. To run containers that require such special permissions, it is necessary to add an annotation to the YAML file describing the workload, which tells virtiofsd to accept such file permissions for that workload. The required annotations are: 

    io.katacontainers.config.hypervisor.virtio_fs_extra_args: |
  [ "-o", "modcaps=+sys_admin", "-o", "xattr" ]

    (BZ#1915377)

  • In the 4.8 release, adding a value to kataConfgPoolSelector by using the OpenShift Container Platform web console causes scheduling.nodeSelector to be populated with an empty value. Pods that use RuntimeClass with the value of kata might be scheduled to nodes that do not have the Kata Containers runtime installed.

    To work around this issue, specify the nodeSelector value manually in the RuntimeClass kata by running the following command: 

    $ oc edit runtimeclass kata

    The following is an example of a RuntimeClass with the correct nodeSelector statement. 

    apiVersion: node.k8s.io/v1
handler: kata
kind: RuntimeClass
metadata:
  creationTimestamp: "2021-06-14T12:54:19Z"
  name: kata
overhead:
  podFixed:
    cpu: 250m
    memory: 350Mi
scheduling:
  nodeSelector:
    custom-kata-pool: "true"

    (BZ#2019384)

  • The OpenShift sandboxed containers Operator details page on Operator Hub contains a few missing fields. The missing fields do not prevent you from installing the OpenShift sandboxed containers Operator in 4.8. (BZ#2019383)
  • Creating multiple KataConfig custom resources results in a silent failure. The OpenShift Container Platform web console does not provide a prompt to notify the user that creating more than one custom resource has failed. (BZ#2019381)
  • Sometimes the Operator Hub in the OpenShift Container Platform web console does not display icons for an Operator. (BZ#2019380)

1.4. Asynchronous errata updates

Security, bug fix, and enhancement updates for OpenShift sandboxed containers 1.0 are released as asynchronous errata through the Red Hat Network. All OpenShift Container Platform 4.8 errata is available on the Red Hat Customer Portal. See the OpenShift Container Platform Life Cycle for more information about asynchronous errata.

Red Hat Customer Portal users can enable errata notifications in the account settings for Red Hat Subscription Management (RHSM). When errata notifications are enabled, users are notified via email whenever new errata relevant to their registered systems are released.

Note

Red Hat Customer Portal user accounts must have systems registered and consuming OpenShift Container Platform entitlements for OpenShift Container Platform errata notification emails to generate.

This section will continue to be updated over time to provide notes on enhancements and bug fixes for future asynchronous errata releases of OpenShift sandboxed containers 1.0.0.

1.4.1. RHBA-2021:3751 - OpenShift sandboxed containers 1.0.2 bug fix advisory

Issued: 2021-10-07

OpenShift sandboxed containers release 1.0.2 is now available. This advisory contains an update for OpenShift sandboxed containers with bug fixes.

The list of bug fixes that are included in the update is documented in the RHBA-2021:3751 advisory.

1.4.2. RHBA-2021:3552 - OpenShift sandboxed containers 1.0.1 bug fix advisory

Issued: 2021-09-16

OpenShift sandboxed containers release 1.0.1 is now available. This advisory contains an update for OpenShift sandboxed containers with bug fixes.

The list of bug fixes that are included in the update is documented in the RHBA-2021:3552 advisory.

1.4.3. RHEA-2021:2546 - OpenShift sandboxed containers 1.0.0 image release, bug fix, and enhancement advisory

Issued: 2021-07-29

The components for OpenShift sandboxed containers release 1.0.0 support for OpenShift Container Platform 4.8 are now available as a technology preview.

The list of bug fixes included in the update is documented in the RHEA-2021:3941 advisory.

Chapter 2. Understanding OpenShift sandboxed containers

OpenShift sandboxed containers support for OpenShift Container Platform provides users with built-in support for running Kata Containers as an additional optional runtime. This is particularly useful for users who are wanting to perform the following tasks:

  • Run privileged or untrusted workloads.
  • Ensure kernel isolation for each workload.
  • Share the same workload across tenants.
  • Ensure proper isolation and sandboxing for testing software.
  • Ensure default resource containment through VM boundaries.

OpenShift sandboxed containers also provides users the ability to choose from the type of workload that they want to run to cover a wide variety of use cases.

You can use the OpenShift sandboxed containers Operator to perform tasks such as installation and removal, updates, and status monitoring.

Sandboxed containers are only supported on bare metal.

Red Hat Enterprise Linux CoreOS (RHCOS) is the only supported operating system for OpenShift sandboxed containers 1.0.0.

2.1. OpenShift sandboxed containers common terms

The following terms are used throughout the documentation.

Sandbox

A sandbox is an isolated environment where programs can run. In a sandbox, you can run untested or untrusted programs without risking harm to the host machine or the operating system.

In the context of OpenShift sandboxed containers, sandboxing is achieved by running workloads in a different kernel using virtualization, providing enhanced control over the interactions between multiple workloads that run on the same host.

Pod

A pod is a construct that is inherited from Kubernetes and OpenShift Container Platform. It represents resources where containers can be deployed. Containers run inside of pods, and pods are used to specify resources that can be shared between multiple containers.

In the context of OpenShift sandboxed containers, a pod is implemented as a virtual machine. Several containers can run in the same pod on the same virtual machine.

OpenShift sandboxed containers Operator

An Operator is a software component that automates operations, which are actions that a human operator could do on the system.

The OpenShift sandboxed containers Operator is tasked with managing the lifecycle of sandboxed containers on a cluster. It deals with operations, such as the installation and removal of sandboxed containers software and status monitoring.

Kata Containers
Kata Containers is a core upstream project that is used to build OpenShift sandboxed containers. OpenShift sandboxed containers integrate Kata Containers with OpenShift Container Platform.
KataConfig
KataConfig objects represent configurations of sandboxed containers. They store information about the state of the cluster, such as the nodes on which the software is deployed.
RHCOS extensions
Red Hat Enterprise Linux CoreOS (RHCOS) extensions are a mechanism to install optional OpenShift Container Platform software. The OpenShift sandboxed containers Operator uses this mechanism to deploy sandboxed containers on a cluster.
Runtime class
A RuntimeClass object describes which runtime can be used to run a given workload. A runtime class that is named kata is installed and deployed by the OpenShift sandboxed containers Operator. The runtime class contains information about the runtime that describes resources that the runtime needs to operate, such as the pod overhead.

2.2. OpenShift sandboxed containers building blocks

The OpenShift sandboxed containers Operator encapsulates all of the components from Kata containers. It manages installation, lifecycle, and configuration tasks.

The OpenShift sandboxed containers Operator is packaged in the Operator bundle format as two container images. The bundle image contains metadata and is required to make the operator OLM-ready. The second container image contains the actual controller that monitors and manages the KataConfig resource.

2.3. RHCOS extensions

The OpenShift sandboxed containers Operator is based on the Red Hat Enterprise Linux CoreOS (RHCOS) extensions concept. The sandboxed containers RHCOS extension contains RPMs for Kata, QEMU, and its dependencies. You can enable them by using the MachineConfig resources that the Machine Config Operator provides.

Additional resources

Chapter 3. Deploying OpenShift sandboxed containers workloads

You can install the OpenShift sandboxed containers Operator using either the web console or OpenShift CLI (oc). Before installing the OpenShift sandboxed containers Operator, you must prepare your OpenShift Container Platform cluster.

3.1. Preparing your cluster for OpenShift sandboxed containers

Before you install OpenShift sandboxed containers, ensure that your OpenShift Container Platform cluster meets the following requirements:

  • Your cluster must be installed on bare metal infrastructure with Red Hat Enterprise Linux CoreOS (RHCOS) workers. Your cluster must use installer-provisioned infrastructure.

    Important
    • OpenShift sandboxed containers only supports RHCOS worker nodes. RHEL 7 or RHEL 8 nodes are not supported.
    • Nested virtualization is not supported.

3.1.1. Additional resource requirements for OpenShift sandboxed containers

OpenShift sandboxed containers is a product that brings the ability to run workloads inside a sandboxed runtime, such as Kata Containers, to your OpenShift Container Platform clusters. Each pod is represented by a virtual machine (VM). Each VM runs in a qemu process and hosts a kata-agent process that acts as a supervisor for managing container workloads and processes that are running in those containers. There are two additional processes that add more overhead:

  • containerd-shim-kata-v2 is used to communicate with the pod.
  • virtiofsd handles host file system access on behalf of the guest.

Each VM is configured with a default amount of memory. Additional memory is hot-plugged into the VM for containers that explicitly request memory.

  • If a container runs without a given memory resource, it is able to consume free memory. It will do so until the total memory used by the VM reaches the default allocation. The guest and its I/O buffers also consume memory.
  • If a container is given a specific amount of memory, then that memory is hot-plugged into the VM before the container starts.
  • If a memory limit is specified, then the workload is terminated if it consumes more memory than the limit. If no memory limit is specified, the kernel that is running on the virtual machine might run out of memory. If the kernel runs out of memory it might terminate other processes on the virtual machine.

Default memory sizes

The following table lists some the default values for resource allocation.

ResourceValue

Memory allocated by default to a virtual machine

2Gi

Guest Linux kernel memory usage at boot

~110Mi

Memory used by the QEMU process (excluding VM memory)

~30Mi

Memory used by the virtiofsd process (excluding VM I/O buffers)

~10Mi

Memory used by the containerd-shim-kata-v2 process

~20Mi

File buffer cache data after running dnf install on Fedora

~300Mi* [1]

  1. File buffers appear and are accounted for in multiple locations:

    • In the guest where it appears as file buffer cache.
    • In the virtiofsd daemon that maps allowed user-space file I/O operations.
    • In the QEMU process as guest memory.
Note

Total memory usage is properly accounted for by the memory utilization metrics, which only count that memory once.

Pod overhead describes the amount of system resources that a pod on a node uses. You can get the current pod overhead for the kata runtime class by using oc describe runtimeclass kata as shown below.

Example

$ oc describe runtimeclass kata

Example output

Name:         kata
[...]
Metadata:
[...]
Overhead:
  Pod Fixed:
    Cpu:     250m
    Memory:  350Mi
[...]

You can change the pod overhead by changing the spec.overhead field for a RuntimeClass. For instance, if the configuration that you run for your containers consumes more than 350Mi of memory for the QEMU process and guest kernel data, you can alter the RuntimeClass overhead to suit your needs.

Note

The specified default overhead values are supported by Red Hat. Changing default overhead values is not supported and can result in technical issues.

Example

kind: RuntimeClass
apiVersion: node.k8s.io/v1
metadata:
  name: kata
overhead:
  podFixed:
    memory: "500Mi"
    cpu: "500m"

  • The default allocation for virtual machines is 2Gi.
  • The Linux kernel uses approximately 100Mi of memory at boot time.
  • The QEMU process uses approximately 30Mi of memory.
  • The virtiofsd process uses approximately 10Mi of memory.
  • The shim-v2 process uses approximately 20Mi of memory.

When performing any kind of file system I/O in the guest, file buffers are allocated in the guest kernel. The file buffers are also mapped in the QEMU process on the host, as well as on the virtiofsd process. For example, if you use 300Mi of file buffer cache in the guest, both QEMU and virtiofsd appear to use 300Mi additional memory. However, the same memory is being used in all three cases. In other words, the total memory usage is only 300Mi, mapped in three different places. This is correctly accounted for when reporting the memory utilization metrics.

Additional resources

3.2. Deploying OpenShift sandboxed containers Operator using the web console

You can install the Operator and view your workloads from the web console.

3.2.1. Installing the OpenShift sandboxed containers Operator using the web console

You can install the OpenShift sandboxed containers Operator from the OpenShift Container Platform web console.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed.
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Open a browser window and log in to the OpenShift Container Platform web console.
  2. From the Administrator perspective, navigate to Operators → OperatorHub.
  3. In the Filter by keyword field, type OpenShift sandboxed containers.
  4. Select the OpenShift sandboxed containers tile.
  5. Read the information about the Operator and click Install.

  6. On the Install Operator page:

    1. Select preview-1.0 from the list of available Update Channel options. This ensures that you install the version of OpenShift sandboxed containers that is compatible with your OpenShift Container Platform version.

    2. For Installed Namespace, ensure that the Operator recommended namespace option is selected. This installs the Operator in the mandatory openshift-sandboxed-containers-operator namespace, which is automatically created if it does not exist.

      Note

      Attempting to install the OpenShift sandboxed containers Operator in a namespace other than openshift-sandboxed-containers-operator causes the installation to fail.

    3. For Approval Strategy, ensure that Automatic, which is the default value, is selected. OpenShift sandboxed containers automatically updates when a new z-stream release is available.
  7. Click Install to make the Operator available to the OpenShift sandboxed containers namespace.

The OpenShift sandboxed containers Operator is now installed on your cluster. You can trigger the Operator by enabling the runtime on your cluster. You can do this by creating the KataConfig custom resource using the OpenShift CLI (oc). 

apiVersion: kataconfiguration.openshift.io/v1
kind: KataConfig
metadata:
  name: example-kataconfig

3.2.2. Viewing OpenShift sandboxed containers workloads from the web console

OpenShift sandboxed containers based workloads look and feel the same as normal workloads when viewed in the web console. The only difference between the two is the runtimeClassName. runtimeClassName is what decides the runtime used for workloads. In this context, the runtime enabled by OpenShift sandboxed containers-based is kata. You can view the runtimeClass that the pods for your workloads use.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Navigate to Administration → Workloads.
  2. Identify the type of workload you want to view details for. For example, Pod, Deployment, DeploymentConfigs objects and so on.
  3. Choose the corresponding workload from the list.
  4. On the Details page, navigate to runtimeClass.
  5. Hover over runtimeClass to view more information. If kata was used as the runtime, the value of the runtimeClass is kata.

3.3. Deploying OpenShift sandboxed containers Operator using the CLI

You can install and deploy the Operator and view workloads from the CLI.

3.3.1. Installing the OpenShift sandboxed containers Operator using the CLI

You can install the OpenShift sandboxed containers Operator using the OpenShift Container Platform CLI.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

  • You have subscribed to the OpenShift sandboxed containers catalog.

    Note

    Subscribing to the OpenShift sandboxed containers catalog provides openshift-sandboxed-containers-operator namespace access to the OpenShift sandboxed containers Operator.

Procedure

  1. Create a YAML file that contains the following manifest: 

    apiVersion: v1
kind: Namespace
metadata:
  name: openshift-sandboxed-containers-operator
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: openshift-sandboxed-containers-kataconfig-group
  namespace: openshift-sandboxed-containers-operator
spec:
  targetNamespaces:
    - openshift-sandboxed-containers-operator
---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: sandboxed-containers-operatorhub
  namespace: openshift-sandboxed-containers-operator
spec:
  source: redhat-operators
  sourceNamespace: openshift-marketplace
  name: sandboxed-containers-operator
  startingCSV: sandboxed-containers-operator.v1.0.0
  channel: "preview-1.0"
  approval: "Automatic"
    Note

    Using the preview-1.0 channel ensures that you install the version of OpenShift sandboxed containers that is compatible with your OpenShift Container Platform version.

  2. Create the required Namespace, OperatorGroup, and Subscription objects for OpenShift sandboxed containers: 

    $ oc create -f <file name>.yaml

  3. Ensure that the Operator is correctly installed: 

    $ oc get csv -n openshift-sandboxed-containers-operator

    Example output

    NAME                             DISPLAY                                  VERSION  REPLACES                    PHASE
openshift-sandboxed-containers   openshift-sandboxed-containers-operator  1.0.0    <csv-of-previous-version>   Succeeded

  4. View the available deployments: 

    $ oc get deployments -n openshift-sandboxed-containers-operator

    Example output

    NAME                                        READY  UP-TO-DATE   AVAILABLE   AGE
openshift-sandboxed-containers-operator                         1/111       9m48s

Verification

  • Verify that the Operator is up and running, so you can create the KataConfig resource to trigger the installation. 

    $ oc get deployments -n openshift-sandboxed-containers-operator

    Example output

    NAME                                                READY   UP-TO-DATE   AVAILABLE   AGE
openshift-sandboxed-containers-controller-manager   1/1     1            1           40d

Additional resources

3.3.1.1. Triggering the installation of the Kata runtime

You must create one KataConfig custom resource (CR) to trigger the OpenShift sandboxed containers Operator to do the following:

  • Install the needed RHCOS extensions, such as QEMU and kata-containers, on your RHCOS node.
  • Ensure that the runtime, CRI-O, is configured with the correct Kata runtime handlers.
  • Create a RuntimeClass custom resource with necessary configurations for additional overhead caused by virtualization and the required additional processes.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Create the KataConfig resource: 

    $ oc create -f <file name>.yaml

    Example

    apiVersion: kataconfiguration.openshift.io/v1
kind: KataConfig
metadata:
  name: cluster-kataconfig

  2. Monitor the installation progress.

    • You can describe the KataConfig installation: 

      $ oc describe kataconfig
      • Verify the Completed nodes field in the status.
      • If the value of Completed nodes matches the number of worker nodes, then the installation is completed. The status also contains a list of nodes where the installation is completed.

    • You can check the progress of the installation by watching the KataConfig resource: 

      $ watch -n 10 oc describe kataconfig

      Alternatively, you can check the status of the KataConfig resource. This can be done by running oc get KataConfig <name> -oyaml and inspecting the status field in the output.

The Kata runtime is now installed on the cluster and ready for use as a secondary runtime. Verify that you see a newly created RuntimeClass for Kata on your cluster.

Important

OpenShift sandboxed containers installs Kata only as a secondary optional runtime on the cluster and not as the primary runtime.

Verification

  • You can monitor the values of the KataConfig custom resource by running: 

    $ watch oc describe KataConfig cluster-kataconfig

Additional resources

3.3.1.2. Selecting nodes for OpenShift sandboxed containers

You can selectively install the Kata runtime on specific workers.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Identify the labels that you want to use for selecting your nodes. For this example, use labels to selects to be chosen as candidates to run on your OpenShift sandboxed containers workloads. If the nodes exist, they are selected.

    1. To apply a label to a node, run the following command: 

      $ oc label node <worker_node_name> <label>=<value>

      This labels your worker node with the <label> label that has a value of <value>.

  2. To add a label selector, edit the KataConfig custom resource (CR): 

    $ oc edit kataconfig

    Example

      apiVersion: kataconfiguration.openshift.io/v1
  kind: KataConfig
  metadata:
    name: cluster-kataconfig
  spec:
    kataConfigPoolSelector:
      matchLabels:
         custom-kata-machine-pool: 'true'

Verification

  • You can check to see if the nodes in the machine-config-pool object are going through a config update.

    • If you are using the default nodes, you can monitor the machine-config-pool resource by running: 

      $ watch oc get mcp worker

    • If you are using selected nodes, you can monitor the machine-config-pool resource by running: 

      $ watch oc get mcp kata-oc

  • You can run watch oc describe kataconfig cluster-kataconfig to display information about sandboxed-containers extension failure on a node. The information is gathered from the status of the machine-config-pool object. You can view the information by running: 

    $ oc describe mcp <machine-config-pool>

3.3.1.3. Scheduling OpenShift sandboxed containers workloads

You can schedule your workloads to run on OpenShift sandboxed containers.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Add runtimeClassName: kata to any pod-templated resources:

    • Pod objects
    • ReplicaSet objects
    • ReplicationController objects
    • StatefulSet objects
    • Deployment objects
    • DeploymentConfig objects

Example for Pod objects

  apiVersion: v1
  kind: Pod
  metadata:
   name: mypod
  spec:
    runtimeClassName: kata

Example for Deployment objects

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: mypod
    labels:
      app: mypod
  spec:
    replicas: 3
    selector:
      matchLabels:
        app: mypod
    template:
      metadata:
        labels:
          app: mypod
      spec:
        runtimeClassName: kata
        containers:
        - name: mypod
          image: myImage

After the pod-templated resource is created with runtimeClassName: kata, OpenShift Container Platform begins scheduling the workload on OpenShift sandboxed containers enabled nodes. If no selector is used, the default is set to all worker nodes. Your workload runs on OpenShift sandboxed containers.

3.3.2. Viewing OpenShift sandboxed containers workloads from the CLI

You can view the runtimeClass that the pods for your workloads use from the CLI.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  • Inspect the runtimeClassName field on the pod to see a pod running on OpenShift sandboxed containers versus a normal container.

    • On the node, each pod has a corresponding qemu process.

Verification

  • You can check the logs of the openshift-sandboxed-containers-operator controller pod to see detailed messages about the steps it is running.

    • You can retrieve the name of the controller pod by running: 

      $ oc get pods -n openshift-sandboxed-containers-operator | grep openshift-sandboxed-containers-operator-controller-manager

      This enables you to monitor the logs of the container manager of that pod.

Chapter 4. Uninstalling OpenShift sandboxed containers

4.1. Uninstalling OpenShift sandboxed containers using the web console

You can uninstall OpenShift sandboxed containers by using the OpenShift Container Platform web console.

4.1.1. Deleting OpenShift sandboxed containers resources

To uninstall OpenShift sandboxed containers, you must first delete the OpenShift sandboxed containers custom resource KataConfig. This removes and uninstalls the kata runtime and its related resources from your cluster.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have access to the cluster as a user with the cluster-admin role.

  • You have no running pods that use kata as the runtimeClassName.

    • You have installed the OpenShift CLI (oc).
    • You the command-line JSON processor (jq) installed.

    • Verify that you have no running pods that use kata as the runtimeClassName by running the following command: 

      $ oc get pods -A -o json | jq -r '.items[] | select(.spec.runtimeClassName | test("kata")).metadata.name'

Procedure

  1. Delete all pods that use runtimeClassName with the value of kata.
  2. From the OpenShift Container Platform web console, select openshift-sandboxed-containers from the Projects list.
  3. Navigate to the Operators → Installed Operators page.
  4. Click OpenShift sandboxed containers.
  5. Click the OpenShift sandboxed containers Operator tab.
  6. Click the scroll-down list in the Operator Details, and then click Delete KataConfig.
  7. Click Delete in the confirmation window.

4.1.1.1. Deleting a namespace using the web console

You can delete a namespace by using the OpenShift Container Platform web console.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Navigate to Administration → Namespaces.
  2. Locate the openshift-sandboxed-containers-operator namespace to delete in the list of namespaces.
  3. On the rightmost side of the namespace listing, select Delete Namespace from the Options menu .

  4. When the Delete Namespace pane opens, enter openshift-sandboxed-containers-operator in the field.

    Note

    If the Delete Namespace option is not available, you do not have permission to delete the namespace.

  5. Click Delete.

4.1.2. Deleting OpenShift sandboxed containers Operator

You can delete the OpenShift sandboxed containers Operator by deleting the catalog subscription and revoking namespace access to the Operator.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Navigate to the Operators → OperatorHub page.
  2. Search for OpenShift sandboxed containers and then select the Operator.
  3. Click Uninstall.
  4. Delete the openshift-sandboxed-containers-operator namespace.

4.2. Uninstalling Kata runtime from the CLI

You can uninstall OpenShift sandboxed containers by using the OpenShift Container Platform command-line interface (CLI).

4.2.1. Deleting OpenShift sandboxed containers resources

You can remove and uninstall the kata runtime and all its related resources, such as CRI-O config and RuntimeClass, from your cluster.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Delete the KataConfig custom resource by running the following command: 

    $ oc delete kataconfig <KataConfig_CR_Name>

  2. Delete the KataConfig custom resource definition by running the following command: 

    $ oc delete crd kataconfigs.kataconfiguration.openshift.io

The OpenShift sandboxed containers Operator removes all resources that were initially created to enable the runtime on your cluster. After you run the preceding commands, your cluster is restored to the state that it was prior to the installation process. You can now delete the openshift-sandboxed-containers-operator namespace.

Verification

  • To verify that the KataConfig custom resource is deleted, run the following command: 

    $ oc get kataconfig <KataConfig_CR_Name>

    Example output

    No KataConfig instances exist

  • To verify that the KataConfig custom resource definition is deleted, run the following command: 

    $ oc get crd kataconfigs.kataconfiguration.openshift.io

    Example output

    Unknown CR KataConfig

4.2.2. Deleting OpenShift sandboxed containers Operator

You can delete the OpenShift sandboxed containers Operator from your cluster.

Prerequisites

  • You have OpenShift Container Platform 4.8 installed on your cluster.
  • You have installed the OpenShift CLI (oc).
  • You have access to the cluster as a user with the cluster-admin role.

Procedure

  1. Delete the OpenShift sandboxed containers Operator subscription from Operator Lifecyle Manager (OLM) by running the following command: 

    $ oc delete subscription openshift-sandboxed-containers-subscription -n openshift-sandboxed-containers-operator

  2. Set the cluster service version (CSV) name for OpenShift sandboxed containers as an environment variable by running the following command: 

    CSV_NAME=$(oc get csv -n openshift-sandboxed-containers-operator -o=custom-columns=:metadata.name)

  3. Delete the CSV name for OpenShift sandboxed containers by running the following command: 

    $ oc delete csv ${CSV_NAME} -n openshift-sandboxed-containers-operator

Chapter 5. Upgrade OpenShift sandboxed containers

You can upgrade the components of OpenShift sandboxed containers by upgrading OpenShift sandboxed containers Operator and OpenShift sandboxed containers artifacts.

5.1. Upgrade OpenShift sandboxed containers Operator

You can use Operator Lifecycle Manager (OLM) to manually or automatically upgrade the OpenShift sandboxed containers Operator. You can select manual or automatic upgrade during the initial deployment. In the context of manual upgrades, the web console shows the available updates that can be installed by the cluster administrator.

Additional resources

5.2. Upgrade the OpenShift sandboxed containers artifacts

The OpenShift sandboxed containers artifacts are deployed onto the cluster using Red Hat Enterprise Linux CoreOS (RHCOS) extensions.

The RHCOS extension sandboxed containers contains the required components to run Kata Containers such as the Kata containers runtime, the hypervisor QEMU, and other dependencies. The extension is upgraded when upgrading the cluster to a new release of OpenShift Container Platform.

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