If you have an existing kubernetes cluster that you are using you may need to get a shell running from inside that cluster to help you debug things. In my scenario access to an ethereum client was locked down to only allow access from the cluster IP address.
Run a geth client on kubernetes
This will give you a command promt so that you can
geth attach http://node-address.com
Run a mongo client on kubernetes
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Port forward from a kubernetes cluster to your local machine
Sometimes you want to run some local tools but connect to soemthing in the cluster, eg connect to a mongo db running in kubernetes.