kubernetes-training

Service are on all node :cluster-wide abstract
kubelet
watches the changes in the cluster using kube-apiserver to create pods on the nodes
invokes CNI to create network for that pod
kubeproxy
watches the changes in the cluster using kube-apiserver, if new service is to be created, it gets into action
When svc is created, it gets an ip addr from a pre-defined range, kubeproxy gets the ip address then create the forwarding rule on each node
The fowarding rule specifies that any traffic that goes to the service’s ip should go to the ip of the pod
Rules: set by kube-proxy --proxy-mode [option]
1. userspace: kubeproxy listens on a port for each service and proxy connection to the pod
2. ipvs rule
3. iptables (default)
To search for NAT rule of a particular service
```
  iptables -L -t nat | grep <svc-name>
```
Service should show to be routed to pod’s ip
Check kubeproxy.log :
```
  cat /var/log/kube-proxy.log
```

kubelet