Discover Red Hat Advanced Cluster Security Cloud Service (RHACS Cloud Service) architecture and concepts.

Red Hat Advanced Cluster Security Cloud Service architecture overview

Red Hat Advanced Cluster Security Cloud Service (RHACS Cloud Service) is a Red Hat managed Software-as-a-Service (SaaS) platform that lets you protect your Kubernetes and OpenShift Container Platform clusters and applications throughout the build, deploy, and runtime lifecycles.

RHACS Cloud Service includes many built-in DevOps enforcement controls and security-focused best practices based on industry standards such as the Center for Internet Security (CIS) benchmarks and the National Institute of Standards Technology (NIST) guidelines. You can also integrate it with your existing DevOps tools and workflows to improve security and compliance.

RHACS Cloud Service
Figure 1. RHACS Cloud Service architecture

Central services include the user interface (UI), data storage, RHACS application programming interface (API), and image scanning capabilities. You deploy your Central service through the Red Hat Hybrid Cloud Console. When you create a new ACS instance, Red Hat creates your individual control plane for RHACS.

RHACS Cloud Service allows you to secure self-managed clusters that communicate with a Central instance. The clusters you secure, called Secured Clusters, are managed by you, and not by Red Hat. Secured Cluster services include optional vulnerability scanning services, admission control services, and data collection services used for runtime monitoring and compliance. You install Secured Cluster services on any OpenShift or Kubernetes cluster you want to secure.


Red Hat manages Central, the control plane for RHACS Cloud Service. It includes three main components: Central, Central DB, and Scanner.

  • Central: Central is the application management interface and services for RHACS Cloud Service. It manages API interactions and user interface access. You can use the same Central instance to secure multiple OpenShift Container Platform or Kubernetes clusters.

  • Central DB: Central DB is the database for RHACS Cloud Service and handles all data persistence. It is currently based on PostgreSQL 13.

  • Scanner: Scanner is a Red Hat-developed and certified vulnerability scanner for scanning container images. Scanner performs the following functions:

    • It analyzes all image layers and checks for known vulnerabilities from the Common Vulnerabilities and Exposures (CVEs) list.

    • It identifies vulnerabilities in installed packages and dependencies for multiple programming languages. In addition to scanning container images, Scanner also identifies vulnerabilities in the node’s operating system and orchestrators. For example, it scans nodes to identify vulnerabilities in Kubernetes, OpenShift Container Platform, and Istio.

Secured cluster services

You install the secured cluster services on each cluster that you want to secure by using the RHACS Cloud Service. Secured cluster services include the following components:

  • Sensor: Sensor is the service responsible for analyzing and monitoring the cluster. Sensor listens to the OpenShift Container Platform or Kubernetes API and Collector events to report the current state of the cluster. Sensor also triggers deploy-time and runtime violations based on RHACS Cloud Service policies. In addition, Sensor is responsible for all cluster interactions, such as applying network policies, initiating reprocessing of RHACS Cloud Service policies, and interacting with the Admission controller.

  • Admission controller: The Admission controller prevents users from creating workloads that violate security policies in RHACS Cloud Service.

  • Collector: Collector analyzes and monitors container activity on cluster nodes. It collects container runtime and network activity information and sends the collected data to Sensor.

  • Scanner: In Kubernetes, the secured cluster services include Scanner-slim as an optional component. However, on OpenShift Container Platform, RHACS Cloud Service installs a Scanner-slim version on each secured cluster to scan images in the OpenShift Container Platform integrated registry and optionally other registries.

Additional resources

Data access and permissions

Red Hat does not have access to the clusters on which you install the secured cluster services. Also, RHACS Cloud Service does not need permission to access the secured clusters. For example, you do not need to create new IAM policies, access roles, or API tokens.

However, RHACS Cloud Service stores the data that secured cluster services send. All data is encrypted within RHACS Cloud Service. Encrypting the data within the RHACS Cloud Service platform helps to ensure the confidentiality and integrity of the data.

When you install secured cluster services on a cluster, it generates data and transmits it to the RHACS Cloud Service. This data is kept secure within the RHACS Cloud Service platform, and only authorized SRE team members and systems can access this data. RHACS Cloud Service uses this data to monitor the security and compliance of your cluster and applications, and to provide valuable insights and analytics that can help you optimize your deployments.