Kubernetes
Kubernetes Architecture
Kubernetes Concepts
Kubernetes Control Plane
- Kubernetes API Server
- Kubernetes Controller Manager
- Kubernetes Scheduler … Makes scheduling decisisons based on available nodes and required pod definitions
- etcd … Database which stores persistent State of the cluster
- Often outsourced to a managed Kubernetes Service, such as Amazon EKS, Azure AKS, Google GKE
- Runs on the Master Kubernetes Node
Kubernetes Node
- Kubelet which talks to the Container Runtime
- kube-proxy networking proxy for routing traffic
- Kubernetes Namespace … Grouping & Organization
- Kubernetes Deployment
- Kubernetes ReplicaSet 1:n Pods
- Kubernetes Pod 1:n Containers, the unit of deployment
Kubernetes Networking
Kubernetes Resources
- Kubernetes Secrets
- Kubernetes CRD’s (CustomResourceDefinitions)
Extending Kubernetes
Kubernetes Operators
Operators are Kubeneretes Clients that manage Kubernetes CRD.
The operator pattern aims to capture the key aim of a human operator who is managing a service or set of services. Human operators who look after specific applications and services have deep knowledge of how the system ought to behave, how to deploy it, and how to react if there are problems.
Examples:
- Use a Prometheus Operator to manage all needed parts
Kubernetes Tools
- Kubernetes IDE Lens https://docs.k8slens.dev/ used by Andreas Murk
- CLI Tool kubectl