vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Scalable web application on Red Hat OpenShift on IBM Cloud 

This tutorial may incur costs. Use the [Cost Estimator](https://cloud.ibm.com/estimator/review) to generate a cost estimate based on your projected usage.

This tutorial walks you through how to deploy an application to a [Red Hat OpenShift on IBM Cloud](https://cloud.ibm.com/kubernetes/catalog/openshiftcluster) cluster from a remote Git repository, expose the app on an Red Hat OpenShift on IBM Cloud route, monitor the health of the environment, and scale the application. Additionally, you will learn how to use a private container registry, deploy an application from a private Git repository and bind a custom domain to your application.

With Red Hat OpenShift on IBM Cloud, you can create IBM Cloud Kubernetes Service clusters with worker nodes that come installed with the Red Hat OpenShift on IBM Cloud Container Platform orchestration software. You get all the [advantages of managed IBM Cloud Kubernetes Service](https://cloud.ibm.com/docs/containers?topic=containers-responsibilities_iks) for your cluster infrastructure environment, while using the [Red Hat OpenShift on IBM Cloud tooling and catalog](https://docs.openshift.com/container-platform/4.12/welcome/index.html) that runs on Red Hat Enterprise Linux for your app deployments.



 Objectives 



* Deploy a web application to the Red Hat OpenShift on IBM Cloud cluster.
* Bind a custom domain.
* Monitor the logs and health of the cluster.
* Scale Red Hat OpenShift on IBM Cloud pods.



Zoom

![Architecture](https://cloud.ibm.com/docs-content/v1/content/f84e2238288b7f0355715a4c355609ce7ac48fb0/solution-tutorials/images/solution50-scalable-webapp-openshift/Architecture.png)

Figure 1. Architecture diagram of the tutorial



1. The developer deploys a web application using the code from a remote Git repository.
Red Hat OpenShift on IBM Cloud toolkit 4.6.0+20210630 4.6.0+20210816 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.6.0+20210816). 







 Change log for worker node fix pack 4.6.42_1552_openshift, released 16 August 2021 

The following table shows the changes that are in the worker node fix pack patch update 4.6.42_1552_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.6.40_1551_openshift

 Component Previous Current Description 

 HA proxy 68e6b3 9c98dc Updated image with fixes for [CVE-2021-27218](https://nvd.nist.gov/vuln/detail/CVE-2021-27218)
: Red Hat OpenShift [4.4.20_1518_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4420_1518), [4.3.35_1539_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4335_1539), and [3.11.272_1567_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_311311272_1567).

Versions
: Worker node fix pack update change log documentation is available.
: Red Hat OpenShift [4.4.20_1517_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4420_1517), [4.3.35_1538_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4335_1538), and [3.11.272_1566_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_311311272_1566).





 3 September 2020 

CA certificate rotation
: Added steps to [revoke existing certificate authority (CA) certificates in your cluster and issue new CA certificates](https://cloud.ibm.com/docs/openshift?topic=openshift-securitycert-rotate).







 August 2020 



 31 August 2020 

Versions
: Worker node fix pack update change log documentation is available.
Red Hat OpenShift on IBM Cloud Metrics Server v4.6.0-20220816 v4.6.0-20220920 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.6.0+20220920). 
 Red Hat OpenShift on IBM Cloud toolkit 4.6.0+20220816 4.6.0+20220920 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.6.0+20220920). 







 Change log for worker node fix pack 4.6.61_1601_openshift, released 26 September 2022 

The following table shows the changes that are in the worker node fix pack 4.6.61_1601_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.6.60_1599_openshift

 Component Previous Current Description 

 RHEL 7 Packages N/A N/A N/A 
 RHEL 8 Packages 4.18.0-372.19.1 4.18.0-372.26.1 N/A 
 Red Hat OpenShift on IBM Cloud. 4.6.60 4.6.61 For more information, see the [change log](https://docs.openshift.com/container-platform/4.6/release_notes/ocp-4-6-release-notes.htmlocp-4-6-61). 







 Change log for worker node fix pack 4.6.60_1599_openshift, released 12 September 2022 

The following table shows the changes that are in the worker node fix pack 4.6.60_1599_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.
Red Hat OpenShift on IBM Cloud toolkit 4.5.0+20210630 4.5.0+20210816 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.5.0+20210816). 







 Change log for worker node fix pack 4.5.41_1548_openshift, released 16 August 2021 

The following table shows the changes that are in the worker node fix pack patch update 4.5.41_1548_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.6.40_1551_openshift

 Component Previous Current Description 

 HA proxy 68e6b3 9c98dc Updated image with fixes for [CVE-2021-27218](https://nvd.nist.gov/vuln/detail/CVE-2021-27218)
5.5.1 Red Hat OpenShift on IBM Cloud can optionally [enable image security enforcement](https://cloud.ibm.com/docs/openshift?topic=openshift-imagesportieris-image-sec). 
 5.6.2 Red Hat OpenShift on IBM Cloud does not annotate all pods with [seccomp profiles](https://kubernetes.io/docs/concepts/security/pod-security-policy/seccomp). 
 5.6.3 Red Hat OpenShift on IBM Cloud deploys some system components that do not set a [pod or container securityContext](https://kubernetes.io/docs/tasks/configure-pod-container/security-context/).
Red Hat OpenShift on IBM Cloud Control Plane Operator, Metrics Server, and toolkit v4.11.0-20230220 v4.11.0-20230314 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.11.0+20230314). 







 Change log for worker node fix pack 4.11.32_1549_openshift, released 27 March 2023 

The following table shows the changes that are in the worker node fix pack 4.11.32_1549_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.11.30_1547_openshift

 Component Previous Current Description 

 RHEL 8 Packages N/A N/A N/A 
 Red Hat OpenShift on IBM Cloud. 4.11.30 4.11.32 For more information, see the [change log](https://docs.openshift.com/container-platform/4.11/release_notes/ocp-4-11-release-notes.htmlocp-4-11-32). 
 Haproxy af5031 8398d1 [CVE-2023-23916](https://nvd.nist.gov/vuln/detail/CVE-2023-23916). 







 Change log for worker node fix pack 4.11.30_1547_openshift, released 13 March 2023 

The following table shows the changes that are in the worker node fix pack 4.11.30_1547_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.11.28_1543_openshift

 Component Previous Current Description
: Updated the Red Hat OpenShift on IBM Cloud CLI plug-in change log page for the [release of version 1.0.231](https://cloud.ibm.com/docs/openshift?topic=openshift-cs_cli_changelog10).





 23 February 2021 

VPE
: Worker node communication to the Kubernetes master is now established over the [VPC virtual private endpoint (VPE)](https://cloud.ibm.com/docs/openshift?topic=openshift-vpc-subnetsvpc_basics_vpe).





 22 February 2021 

Master versions
: Master fix pack update change log documentation is available for version [4.6.16_1532_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_464616_1532), [4.5.31_1530_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4531_1530), [4.4.33_1534_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4433_1534), [4.3.40_1555_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-changelog_archive4340_1555), and [3.11.380_1581_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_311311380_1581).





 20 February 2021 

Certified Kubernetes
: Version [4.6 (Kubernetes 1.19)](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_versions) release is now certified.





 17 February 2021 

New! Red Hat OpenShift 4.6
Red Hat OpenShift on IBM Cloud Control Plane Operator v4.6.0-20220614 v4.6.0-20220712 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.6.0+20220712). 
 Red Hat OpenShift on IBM Cloud Metrics Server v4.6.0-20220614 v4.6.0-20220712 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.6.0+20220712). 
 Red Hat OpenShift on IBM Cloud toolkit 4.6.0+20220614 4.6.0+20220712 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.6.0+20220712). 







 Change log for worker node fix pack 4.6.59_1591_openshift, released 18 July 2022 

The following table shows the changes that are in the worker node fix pack 4.6.59_1591_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.6.59_1590_openshift

 Component Previous Current Description
3.2.2 Red Hat OpenShift on IBM Cloud can optionally [enable Kubernetes API server auditing](https://cloud.ibm.com/docs/openshift?topic=openshift-health-audit). 
 4.2.6 Red Hat OpenShift on IBM Cloud does not protect kernel defaults to allow customers to tune kernel parameters. 
 4.2.8 Red Hat OpenShift on IBM Cloud ensures that the hostname matches the name issued by the infrastructure. 
 5.1.2 Red Hat OpenShift on IBM Cloud deploys some system components that could have their Kubernetes secret access further restricted. 
 5.1.3 Red Hat OpenShift on IBM Cloud deploys some system components that could have their Kubernetes resource access further restricted. 
 5.1.5 Red Hat OpenShift on IBM Cloud does not set [automountServiceAccountToken: false](https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/use-the-default-service-account-to-access-the-api-server) for each default service account. 
 5.1.6 Red Hat OpenShift on IBM Cloud deploys some system components that could set [automountServiceAccountToken: false](https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/use-the-default-service-account-to-access-the-api-server). 
 5.2.1 Red Hat OpenShift on IBM Cloud can optionally configure [Red Hat OpenShift security context constraints](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_scc) and [Kubernetes pod security admission](https://kubernetes.io/docs/concepts/security/pod-security-admission/) which are similar to the deprecated [Kubernetes pod security policies](https://kubernetes.io/docs/concepts/security/pod-security-policy/).
Red Hat OpenShift on IBM Cloud toolkit 4.7.0+20210608 4.7.0+20210630 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.7.0+20210630). 







 Change log for worker node fix pack 4.7.19_1525_openshift, released 19 July 2021 

The following table shows the changes that are in the worker node fix pack 4.7.19_1525_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.7.18_1524_openshift

 Component Previous Current Description 

 Red Hat OpenShift 4.7.18 4.7.19 See the [Red Hat OpenShift release notes](https://docs.openshift.com/container-platform/4.7/release_notes/ocp-4-7-release-notes.htmlocp-4-7-19). 
 RHEL 7 Packages N/A N/A Updated worker node image with package updates. 







 Change log for worker node fix pack 4.7.18_1524_openshift, released 6 July 2021 

The following table shows the changes that are in the worker node fix pack 4.7.18_1524_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.7.16_1522_openshift

 Component Previous Current Description
For more information about other changes, see [release notes](https://www.haproxy.org/download/1.8/src/CHANGELOG). 
 Red Hat OpenShift node 3.11.129 3.11.135 For more information, see the [Red Hat OpenShift release notes](https://docs.openshift.com/container-platform/3.11/release_notes/ocp_3_11_release_notes.htmlocp-3-11-135). 
 RHEL 7 kernel 3.10.0-957.21.3.el7 3.10.0-1062.el7 Updated worker node images with kernel and package updates for [CVE-2018-16881](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-168810), [CVE-2019-6470](https://nvd.nist.gov/vuln/detail/CVE-2019-6470), [CVE-2018-14618](https://nvd.nist.gov/vuln/detail/CVE-2018-14618), [CVE-2018-16062](https://nvd.nist.gov/vuln/detail/CVE-2018-16062), [CVE-2018-16402](https://nvd.nist.gov/vuln/detail/CVE-2018-16402), [CVE-2018-16403](https://nvd.nist.gov/vuln/detail/CVE-2018-16403), [CVE-2018-18310](https://nvd.nist.gov/vuln/detail/CVE-2018-18310), [CVE-2018-18520](
For a list of available operating sysems by cluster version, see [Available Red Hat OpenShift versions](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_versionsopenshift_versions_available). Note that to use your RHCOS hosts in your clusters, you must create a Red Hat CoreOS-enabled location and a cluster that runs version 4.9 or later. If no option is specified, the default [operating system that corresponds to the cluster version](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_versionsopenshift_versions_available) is used.

Example cluster create command.

ibmcloud oc cluster create satellite --location <location_name_or_ID> --name <cluster_name> --pull-secret <secret> --version 4.11_openshift [--enable-admin-agent] [--host-label LABEL ...] [--operating-system (REDHAT_7_64|REDHAT_8_64|RHCOS)] [--pod-subnet SUBNET] [-q] [--service-subnet SUBNET] [--workers <workers_per_zone>] [--zone <zone_name>]

Example cluster create command using RHCOS hosts and cluster version 4.9.23_1122.

ibmcloud oc cluster create satellite --location <location_name_or_ID> --name <cluster_name> --pull-secret <secret> --version 4.9.23_1122_openshift --enable-admin-agent --operating-system RHCOS

Example output

Creating cluster...
OK
Cluster created with ID brkhsd220b6ktv7sjl50
4. Wait for the cluster to reach a Warning state. The Warning state indicates that the cluster master is fully deployed, but no worker nodes could be detected in the cluster.

ibmcloud oc cluster ls

Example output

OK
Name ID State Created Workers Location Version Resource Group Name Provider
: Red Hat OpenShift on IBM Cloud [4.7.45_1559_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_47), [4.6.56_1578_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_46), [3.11.634_1626_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_311).





 28 March 2022 

Worker node fix pack update.
: Red Hat OpenShift [4.9.25_1533_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_49), [4.8.35_1550_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_48), [4.7.45_1557_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_47), [4.6.56_1577_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_46), [3.11.634_1627_openshift](https://cloud.ibm.com/docs/openshift?topic=openshift-openshift_changelog_311).





 24 March 2022 

IBM Cloud Object Storage plug-in
: Version 2.1.13 of the IBM Cloud Object Storage plug-in [is available](https://cloud.ibm.com/docs/openshift?topic=openshift-cos_plugin_changelog).

Block Storage for VPC add-on.
Red Hat OpenShift Control Plane Operator Master v4.3.0-20200615 v4.4.0-20200615 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.4.0+20200615). 
 Red Hat OpenShift Both Master 4.3.28 <br>Worker 4.3.29 4.4.11 See the [Red Hat OpenShift release notes](https://docs.openshift.com/container-platform/4.4/release_notes/ocp-4-4-release-notes.htmlocp-4-4-11). 
 RHEL 7 Packages Worker N/A N/A Updated worker node images with package updates for [CVE-2020-12049](https://nvd.nist.gov/vuln/detail/CVE-2020-12049). 
 Red Hat OpenShift on IBM Cloud toolkit Master 4.3.0+20200615 4.4.0+20200615 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.4.0+20200615). 









 Version 4.3 change log (unsupported as of 7 March 2021) 

Version 4.3 is unsupported. You can review the following archive of the 4.3 change logs.



 Change log for worker node fix pack 4.3.40_1555_openshift, released 1 March 2021 

The following table shows the changes that are in the worker node fix pack 4.3.40_1555_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.3.40_1554_openshift

 Component Previous Current Description
Changes since version 4.5.28_1528_openshift

 Component Previous Current Description 

 Red Hat OpenShift 4.5.28 4.5.31 See the [Red Hat OpenShift release notes](https://docs.openshift.com/container-platform/4.5/release_notes/ocp-4-5-release-notes.htmlocp-4-5-31). 
 RHEL 7 Packages 3.10.0-1160.11.1.el7 3.10.0-1160.15.2.el7 Updated worker node with image kernel and package updates for: [CVE-2020-10543](https://nvd.nist.gov/vuln/detail/CVE-2020-10543), [CVE-2020-10878](https://nvd.nist.gov/vuln/detail/CVE-2020-10878), [CVE-2020-12723](https://nvd.nist.gov/vuln/detail/CVE-2020-12723), [CVE-2020-15436](https://nvd.nist.gov/vuln/detail/CVE-2020-15436), [CVE-2020-35513](https://nvd.nist.gov/vuln/detail/CVE-2020-35513), [CVE-2019-25013](https://nvd.nist.gov/vuln/detail/CVE-2019-25013), [CVE-2020-10029](https://nvd.nist.gov/vuln/detail/CVE-2020-10029), [CVE-2020-29573](https://nvd.nist.gov/vuln/detail/CVE-2020-29573), and [CVE-2020-12321](https://nvd.nist.gov/vuln/detail/CVE-2020-12321)){: external}. 







 Change log for worker node fix pack 4.5.28_1528_openshift, released 1 February 2021
Red Hat OpenShift on IBM Cloud toolkit 4.7.0+20220308 4.7.0+20220411 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.7.0%2B20220411). 







 Change log for worker node fix pack 4.7.49_1562_openshift, released 25 April 2022 



Changes since version 4.7.46_1560_openshift

 Component Previous Current Description 

 RHEL 7 Packages N/A N/A Package updates. 
 Red Hat OpenShift on IBM Cloud. 4.7.46 4.7.49 For more information, see the [change log](https://docs.openshift.com/container-platform/4.7/release_notes/ocp-4-7-release-notes.htmlocp-4-7-49). 







 Change log for worker node fix pack 4.7.46_1560_openshift, released 11 April 2022 

The following table shows the changes that are in the worker node fix pack 4.7.46_1560_openshift. Worker node patch updates can be applied by updating, reloading (in classic infrastructure), or replacing (in VPC infrastructure) the worker node.



Changes since version 4.7.45_1557_openshift

 Component Previous Current Description
Red Hat OpenShift 4.8.11 4.8.14 See the [Red Hat OpenShift release notes](https://docs.openshift.com/container-platform/4.8/release_notes/ocp-4-8-release-notes.htmlocp-4-8-14). 
 Red Hat OpenShift Control Plane Operator v4.8.0-20210917 v4.8.0-20211004 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.8.0+20211004). 
 OpenVPN Operator image v1.3.6 v1.3.7 Updated ansible operator base image to version v1.12.0 to resolve CVEs. 
 Portieris admission controller v0.11.0 v0.12.0 See the [Portieris admission controller release notes](https://github.com/IBM/portieris/releases/tag/v0.12.0). 
 Red Hat OpenShift on IBM Cloud Metrics Server v4.8.0-20210917 v4.8.0-20211004 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.8.0+20211004). 
 Red Hat OpenShift on IBM Cloud toolkit 4.8.0+20210917 4.8.0+20211004 See the [Red Hat OpenShift on IBM Cloud toolkit release notes](https://github.com/openshift/ibm-roks-toolkit/releases/tag/v4.8.0+20211004). 







 Change log for worker node fix pack 4.8.15_1532_openshift, released 25 October 2021 

The following table shows the changes that are in the worker node fix pack patch update 4.8.15_1532_openshift.
* [Worker nodes](https://cloud.ibm.com/docs/openshift?topic=openshift-securityworkernodes)
* [Network](https://cloud.ibm.com/docs/openshift?topic=openshift-securitynetwork)
* [Persistent storage](https://cloud.ibm.com/docs/openshift?topic=openshift-securitystorage)
* [Monitoring and Logging](https://cloud.ibm.com/docs/openshift?topic=openshift-securitymonitoring_logging)
* [Container images and registry](https://cloud.ibm.com/docs/openshift?topic=openshift-securityimages_registry)
* [Container isolation and security](https://cloud.ibm.com/docs/openshift?topic=openshift-securitycontainer)
* [Personal information](https://cloud.ibm.com/docs/openshift?topic=openshift-securitypi)







 Red Hat OpenShift API server and etcd 

The Red Hat OpenShift API server and etcd data store are the most sensitive components that run in your Red Hat OpenShift master. You want to prevent unauthorized access to these components because they set and store the configurations for all the resources that run in your cluster, including some security settings of your applications.

Red Hat OpenShift provides security controls and limits access to protect these components and reduce the risk of cyber attacks.



 How is access to my API server granted? 

By default, Kubernetes requires every request to go through several stages before access to the API server is granted.

Authentication
: Validates the identity of a registered user or service account.

Authorization
: Limits the permissions of authenticated users and service accounts to ensure that they can access and operate only the cluster components that you want them to.

Admission control
: Validates or mutates requests before they are processed by the Red Hat OpenShift API server. Many Kubernetes features require admission controllers to properly function.