Certified Specialist OpenShift Administration on RHCOS

Certified Specialist OpenShift Administration on RHCOS

Domain 1: RHCOS Architecture, Node Scaling, and Cluster Updates

• Objective: Validate the understanding of the immutable RHCOS architecture and the ability to manage, scale, and update cluster nodes using OpenShift's native Machine API.
• Key Competencies:
  • Understanding the immutable nature of RHCOS (rpm-ostree) and troubleshooting nodes using debug pods (oc debug node).
  • Managing node configurations at scale using the Machine Config Operator (MCO) and applying custom MachineConfigs (e.g., SSH keys, kernel arguments).
  • Provisioning and scaling worker nodes dynamically using MachineSets and the Machine API.
  • Executing safe, automated over-the-air (OTA) cluster updates and rollbacks using the Cluster Version Operator (CVO).

Domain 2: Enterprise Authentication, RBAC, and Security Contexts

• Objective: Evaluate proficiency in securing the OpenShift environment, integrating corporate identity, and strictly controlling what workloads are permitted to execute.
• Key Competencies:
  • Configuring and managing OAuth Identity Providers (IdP) such as LDAP, Active Directory, or HTPasswd for cluster access.
  • Implementing granular Role-Based Access Control (RBAC) by assigning Roles, ClusterRoles, and managing RoleBindings for users and groups.
  • Applying and troubleshooting Security Context Constraints (SCCs) to control pod execution privileges (e.g., preventing containers from running as root or accessing host networks).
  • Managing cluster-wide and namespace-level Secrets and ConfigMaps for secure application deployment.

Domain 3: Persistent Storage and Advanced Cluster Networking

• Objective: Assess the skills required to connect applications to the outside world, isolate internal traffic, and provision enterprise storage.
• Key Competencies:
  • Configuring and exposing applications externally using OpenShift Routes, Ingress Controllers, and managing TLS edge termination.
  • Implementing internal network isolation using NetworkPolicies within the default OVN-Kubernetes or OpenShift SDN networking layers.
  • Provisioning persistent storage by managing StorageClasses, Persistent Volumes (PVs), and Persistent Volume Claims (PVCs) using the Container Storage Interface (CSI).
  • Configuring dynamic storage provisioning with enterprise backends (e.g., Red Hat OpenShift Data Foundation / Ceph).

Domain 4: Resource Management, Observability, and Operator Lifecycle

• Objective: Test the capability to monitor cluster health, prevent resource exhaustion, and extend cluster functionality using Operators.
• Key Competencies:
  • Configuring ResourceQuotas and LimitRanges per namespace to manage CPU and memory consumption across developer teams.
  • Utilizing the integrated Prometheus and Grafana stack to monitor cluster health, review metrics, and configure custom Alertmanager rules.
  • Managing platform extensions and third-party software using the Operator Lifecycle Manager (OLM), including installing, updating, and troubleshooting Operators.
  • Diagnosing workload failures by extracting container logs, querying cluster events, and analyzing pod scheduling issues.