I'm interested to know tried and tested techniques for running CLI applications against a Kubernetes cluster.
Our services take the form of docker images. It seems logical that our CLI applications should also be docker images. This gives us a bunch of options to run CLI applications against services inside our Kubernetes cluster.
Ultimately we can run the images locally (docker run) run them inside the cluster (kubectl run) or have a "noop" container we run commands in (kubectl exec). The main downside of running outside is we don't get context (like DNS). But running inside seems like it might be slow: slow start up as image is pulled on to a node and the latency involved in running an interactive terminal over HTTP. The "noop" container feels a bit hacky.
Does anyone have any other approaches to this problem?
There is Jobs for this:
A job creates one or more pods and ensures that a specified number of them successfully terminate. As pods successfully complete, the job tracks the successful completions. When a specified number of successful completions is reached, the job itself is complete. Deleting a Job will cleanup the pods it created.