Kubernetes Networking Model (KNM)
- KNM requirements are
- all pods can communicate with all other pods without using NAT
- all Nodes can communicate with all Pods without NAT
- the IP that Podsees itself is the same IP that other see it as
- Lets understand the following
- Container to Container networking
- Pod-to-Pod Networking
- Pod-to-svc networking
- Internet to SVC networking
Container to Container Networking
Pod to Pod Networking
- Both Pods in Same Node
- Pods on different nodes
- Pod to Service IP Address
Health Checks of Pod
- When we run our application in k8s, it is kept alive using process health check.
- However in most cases a simple process might not be enough
- process has deadlocked and unable to serve requests (process check will return as application is health)
- To address this, k8s introduced health checks for application liveness
- Liveness Probe: This probe checks for application specific logic to verify that the application is still running
- Containers that fail liveness probe will be restarted.
- Readiness probe describes when a container is ready to serve user requests. Containers that fail readiness check are removed from service (load balancers)
- Refer Here for the liveness probe.
K8s in the Cloud as a service
- Azure Kubernetes Service (AKS)
- AWS Elastic Kubernetes Service (EKS)
