Networking

• Docker Networking - CNM
• CNI
• Cluster Networking
• Pod Networking
  • IP Addesses are uniquely shared among Nodes.
  • Each Pod on a Node gets an IP address assigned.
• CNI in kubernetes
• CNI Rules
  • Container Runtime must create network namespace
  • Identify network the container must attach to
  • Container Runtime to invoke Network Plugin (bridge) when container is ADDed.
  • Container Runtime to invoke Network Plugin (bridge) when container is DELeted.
  • JSON format of the Network Configuration
• Get CNIs installed
  • ls -l /etc/cni/net.d
  • ps aux | grep kube-api
• CNI weave
• IP Address Management - Weave
• Service Networking
• 
  • uses IP tables in namespaces
  • spread across the host
  • Get Service Ip Address range
  • ps aux | grep kube-api --service-cluster-ip-range=10.96.0.0/12 iptables -L -t nat | grep nginx
• DNS in kubernetes
  • Objectives:
    • Service DNS : nginx-dep.default.svc.cluster.local
    • POD DNS : my-pod.default.pod.cluster.local
• CoreDNS in Kubernetes
• Ingress