Uniform API server access using clientcmd

Uniform API server access using clientcmd General philosophy Available features Configuration merging Overall process Configure the loading rules Configure the overrides Build a set of flags Bind the flags Build the merged configuration Obtain an API client Full example If you've ever wanted to develop a command line client for a Kubernetes API, especially if you've considered making your client usable as a kubectl plugin, you might have wondered how to make your client feel familiar to users of kubectl. A quick glance at the output of kubectl options might put a damper on that: "Am I really supposed to implement all those options?" kubectl kubectl kubectl options Fear not, others have done a lot of the work involved for you. In fact, the Kubernetes project provides two libraries to help you handle kubectl -style command line arguments in Go programs: clientcmd and cli-runtime (which uses clientcmd ). This article will show how to use the former. kubectl clientcmd cli-runtime clientcmd As might be expected since it's part of client-go , clientcmd 's ultimate purpose is to provide an instance of restclient. Config that can issue requests to an API server. client-go clientcmd restclient. Config It follows kubectl semantics: kubectl defaults are taken from ~/. kube or equivalent; ~/. kube files can be specified using the KUBECONFIG environment variable; KUBECONFIG all of the above settings can be further overridden using command line arguments. It doesn't set up a --kubeconfig command line argument, which you might want to do to align with kubectl ; you'll see how to do this in the "Bind the flags" section. --kubeconfig kubectl clientcmd allows programs to handle clientcmd kubeconfig selection (using KUBECONFIG ); kubeconfig KUBECONFIG context selection; namespace selection; client certificates and private keys; user impersonation; HTTP Basic authentication support (username/password).