Kubernetes Architecture
Clusters
- A Kubernetes cluster consists of:
- Master Node (Control Plane)
- Worker Nodes
Worker Nodes
- Run actual application workloads
- Each worker node runs:
kubelet – communicates with control plane- Containers inside Pods
Master Node Components
- API Server
- Entry point to the cluster
- Used by
kubectl, dashboards, APIs
- Controller Manager
- Monitors cluster state
- Maintains desired cluster state
- Restarts pods, fixes mismatches
- Scheduler
- Decides which node runs which pod
- Based on resource availability
- On which worker node next container to be schedule
- etcd ⚠️
- Key-value store
- Stores entire cluster state (config + status)
- Source of truth for backup & restore
- Virtual Network
- Enables pod-to-pod communication
- Makes multiple nodes behave like one machine
