Certified Kubernetes Administrator
https://training.linuxfoundation.org/certification/certified-kubernetes-administrator-cka/
The CKA was created by the Linux Foundation and the Cloud Native Computing Foundation (CNCF) as a part of their ongoing effort to help develop the Kubernetes ecosystem. The exam is online, proctored, performance-based test that requires solving multiple tasks from a command line running Kubernetes.
Storage 🫙
- Understand storage classes, persistent volumes
- Understand volume mode, access modes and reclaim policies for volumes
- Understand persistent volume claims primitive
- Know how to configure applications with persistent storage
Troubleshooting 🤔
- Evaluate cluster and node logging
- Understand how to monitor applications
- Manage container stdout & stderr logs
- Troubleshoot application failure
- Troubleshoot cluster component failure
- Troubleshoot networking
Workloads & Scheduling ⚙️⏱️
- Understand deployments and how to perform rolling update and rollbacks
- Use ConfigMaps and Secrets to configure applications
- Know how to scale applications
- Understand the primitives used to create robust, self-healing, application deployments
- Understand how resource limits can affect Pod scheduling
- Awareness of manifest management and common templating tools
Cluster Architecture, Installation & Configuration 👷
- Manage role based access control (RBAC)
- Use Kubeadm to install a basic cluster
- Manage a highly-available Kubernetes cluster
- Provision underlying infrastructure to deploy a Kubernetes cluster
- Perform a version upgrade on a Kubernetes cluster using Kubeadm
- Implement etcd backup and restore
Services & Networking 🛜
- Understand host networking configuration on the cluster nodes
- Understand connectivity between Pods
- Understand ClusterIP, NodePort, LoadBalancer service types and endpoints
- Know how to use Ingress controllers and Ingress resources
- Know how to configure and use CoreDNS
- Choose an appropriate container network interface plugin
Study Plan
1. Goal
- Pass the CKA certification exam within 4 Months.
- Build hands-on expertise with Kubernetes clusters.
2. Timeline
- Duration: 16 weeks (can be adjusted based on your schedule).
- Daily Commitment: 2-3 hours/day.
- Weekly Breakdown:
- Focus on specific topics aligned with the CKA exam curriculum.
- Reserve time for labs, practice, and review.
3. Resources
- Books & Guides:
- Kubernetes Up & Running* by Kelsey Hightower.
- Official Kubernetes documentation: Kubernetes Docs
- Labs:
- Killercoda labs
- K3s on personal ProxMox lab
Study Notes
1. The Complexity of Kubernetes
- Kubernetes is often described as a vast “Rabbit Hole” 🕳️ with layers of concepts and tools. However, understanding why Kubernetes exists and how it works provides a solid foundation that will help immensely. 🚴
2. The Roots of Containerization
- The concept of CHROOT was one of the early steps toward what we now call containerization. 📦
- Containerization gained popularity with Docker, making it easy to package and deploy applications in isolated environments.
3. Containers on Virtual Machines: A Limitation
- Initially, containers would run within Virtual Machines (VMs), which limited their efficiency and scalability.
- Over time, as more VMs were needed to handle application loads, this setup led to increased complexity.
4. Managing VMs Before Kubernetes
- Before Kubernetes, Ansible was commonly used in multi-VM setups to handle deployments with a push-based workflow.
- However, this approach had a critical flaw:
- Lack of Communication: Each VM operated independently, with no real-time feedback between them.
- Sync Challenges: Keeping configurations synchronized across VMs was tedious, especially when maintenance was required on a single VM.
5. Enter Kubernetes: The Cloud Operating System
- Kubernetes was introduced to address these limitations and is often considered the operating system of the cloud.
- It allows a cluster of VMs (or nodes) to communicate and coordinate, enabling more efficient resource management and orchestration at scale.