I had the pleasure recently of passing CNCF CKA exam, three weeks before that I have passed the Red Hat certificate of expertise platform as a service exam; for the rest of us that is what Red Hat now addresses as Openshift Container Platform OCP3. Some friends and social media contacts have been asking, how did I prepare for the CKA exam? and how does it differ from OCP3 exam from Red Hat?. I will try to reflect my experience without breaking any signed exams Non-disclosure agreement “NDA”.
Both exams are hands-on performance-based exams, so the key here is to have lots of hands-on exposure, practice and know your platform theory and documentation well. Both Openshift and Kubernetes project documentation is excellent sufficient resources. Ensure you are studying and using the same version that will be in the exam, at the time of writing it is Openshift 3.5 for Red Hat and Kubernetes 1.6.2 for the CKA exam.
Study: I have prepared for “OCP3" Red Hat certificate of expertise platform as a service exam using Red Hat Online Learning Subscription.
Prepared for the CKA using mostly free online resources. Safaribooksonline subscription did help to access the early release of “Kubernetes up & running” by Brendan Burns, Kelsey Hightower, Joe Beda. Some k8s conference workshop videos such as Kelsey Hightower OSCON 2017 “Kubernetes Hands-on” and Sébastien Goasguen live online training “Kubernetes Introduction”.
Resources I have used are documented in my My GitHub CKA exam references repo: Kubernetes-Certified-Administrator cross-references repo
Other ways to prepare is to take official courses:
Linux foundation courses:
Passing score: in general Red Hat passing score as of today is 70% 210 out of 300. Red Hat tasks are not marked, hard to tell the distribution of grades. For CKA the passing score is a bit higher 74%. questions(tasks) are marked graded and the difficulty and grade levels were gradual; easy straightforward questions came first, hard highly graded questions were last such as troubleshooting.
CKA questions have the advantage that each question is an independent task that does not affect other exam tasks, and you can go back and forward if you get stuck or if you feel courageous enough to start with the high graded questions at the end.
The coverage of stated objectives for both CKA and OCP3 exams are pretty good and distributed well during both exams. I feel both exams do complement each other with CKA giving better focus to operations (installation, configuration, validation, maintenance , security, troubleshooting, logging, monitoring,..etc) while OCP3 focus is more into PaaS with around 60% of the focus on applications deployments, OCP3 application deployment objectives are more targeted toward OCP3 features and present realistic doable real-life use cases within the allotted exam time constraints.
Timing : the Red Hat Openshift exam is three hours of installation, configuration and different diverse application and service deployment as described in the exam objectives while CKA is 4 hours, again I can not stress the need for good practice as during the exam you do not have much time to look things up, time passes quickly and you might not have time to go back review and validate your answer, I validate as I go along and ensure that my configurations will survive a reboot of the machines and services involved. And use the notes feature of the exam to keep track of something that I need to revisit back. If I get stuck more than 10 mins in the same task, I note it down on the provided note app and return back to it later.
Red Hat teaches you one easy way to install, configure and deploy an internet disconnected small Openshift cluster, and there are no troubleshooting objective unless you break something by mistake, typo, or miss a step, the recent openshift 3.5+ install, configure, and deploy are smooth, hassle-free, self-driven, and well documented. The CKA, the exam environment is based on Canonical Distribution of Kubernetes and you have the freedom to configure, tune, troubleshoot, fix and install some of the cluster components if needed whatever way you like. I have found Kelsey Hightower “Kubernetes the hard way” as a valuable resource to master k8s components and installation. The cka exam you are allowed to search google for errors, kubernetes.io and GitHub as long as it is not directly exam question-related.
For practice I used minikube, GCE k8s cluster, and two vagrant labs one based on kubeadm, and the other on kubespray, they also provided a good platform for breaking/troubleshooting scenarios. not to forget katacoda and kubernetes by example demo and learning sites, they are a must visit.
I will keep updating the Github repo given time.
if you like interactive Q/A, and online slack meetups join Kubernauts, more exam info can be found from CNCF: