What are some common kubectl commands?

The commands below are used for general troubleshooting, and are immensely helpful to provide when opening a support ticket.  They are also used during upgrades, joining/removing nodes and while actively troubleshooting.  All the commands below can be run as a one-liner.

1.  This will show the status of the pods, jobs and nodes and show additional information in one command:

sudo KUBECONFIG=/etc/kubernetes/admin.conf kubectl get pods,jobs,nodes -o wide

2.  Display the logs of a pod (found using the command above), and search for a particular string of text:

sudo KUBECONFIG=/etc/kubernetes/admin.conf kubectl logs [pod name] -f | grep foo

3.  Display the logs of a pod that are 1 minute old:

sudo KUBECONFIG=/etc/kubernetes/admin.conf kubectl logs [podname] --since=1m

4.  Display the previous logs from a pod that has restarted:

sudo KUBECONFIG=/etc/kubernetes/admin.conf kubectl logs [podname] -p

5.  Show the status of Cassandra database:

sudo KUBECONFIG=/etc/kubernetes/admin.conf kubectl exec -ti cassandra-0 nodetool status