Containers look like a new world, but they are built from features of the Linux kernel that administrators already know: processes, namespaces, control groups, file systems, networking and SELinux. That is why strong Linux skills make OpenShift far easier.
Why Linux first
- Troubleshooting. When a pod will not start, the cause is often a file permission, a full disk, a DNS problem or an SELinux denial.
- Networking. Services, routes and network policies make more sense once you understand IP, ports, firewalls and DNS.
- Storage. Persistent volumes map to real file systems and LVM concepts.
A suggested path
- RHCSA (EX200). Command line, users, storage, systemd, networking, firewalld, SELinux and Podman.
- Containers and Kubernetes fundamentals. Images, registries, Pods, Deployments, Services.
- OpenShift administration. Routes, builds, RBAC, quotas, storage, Operators, monitoring and updates.
- Automation. RHCE and Ansible for repeatable cluster and host configuration.
What changes with OpenShift
OpenShift adds opinionated security defaults, a web console, integrated builds, Operators and a supported lifecycle on top of Kubernetes. Administrators spend time on authentication, RBAC, security context constraints, quotas and cluster updates.
Practise on a real cluster
Reading YAML is not enough. Deploy an app, expose it, break its configuration, read the events and fix it. That loop is the heart of our OpenShift programme, which follows the DO180 to DO280 progression and prepares you for the EX280 practical exam.