I am trying to open the terminal inside the container and execute the command.
When I use this: kubectl exec -it POD_NAME, I cannot connect, I see connection timeout.
Do you know other methods instead of kubectl exec to open a terminal inside the container?
Yes!
ssh into the Kubernetes node/machine where your container is running and run:
$ docker exec -it <container-name> shor if you have bash in the container
$ docker exec -it <container-name> bashThe fact that it's timing out means that you may have some other networking issues in your cluster like a firewall preventing access, your kube-apiserver not being accessible, or your network overlay not configured the way it's supposed to.
This is the best guide I know to understand how kubectl exec ... works under the hood, if you'd like to understand where things might be wrong.