To start, it’s useful to note and remember that in Kubernetes, every pod gets its own ip address from 10.*, that is usable only within the cluster. Now, the port-forward feature of kubectl simply tunnels the traffic from a specified port at your local host machine to the specified port on the specified pod. API server then becomes, in a sense, a temporary gateway between your local port and the Kubernetes cluster.
kubectl port-forward forwards connections to a local port to a port on a pod. Compared to kubectl proxy, kubectl port-forward is more generic as it can forward TCP traffic while kubectl proxy can only forward HTTP traffic.
kubectl port-forward is useful for testing/debugging purposes so you can access your service locally without exposing it.
Below is the name of the pod and it will forward it’s port 6379 to localhost:6379.
kubectl port-forward redis-master-765d459796-258hz 6379:6379
which is the same as
kubectl port-forward pods/redis-master-765d459796-258hz 6379:6379
or
kubectl port-forward deployment/redis-master 6379:6379
or
kubectl port-forward rs/redis-master 6379:6379
or
kubectl port-forward svc/redis-master 6379:6379