main.go

kubeConfig, err := clientcmd.LoadFromFile(kubeconfig)
check("The following error occured while loading the KubeConfig file", err)
if _, v := kubeConfig.Clusters[*clusterPtr]; !v {
  log.Fatal(fmt.Sprintf("Cluster \"%s\" was not found in the current Kube Config file", *clusterPtr))
}
kc := &KubeConfig{
  APIVersion: "v1",
  Clusters: Clusters{
    0: {
      Cluster{
        base64.StdEncoding.EncodeToString([]byte(kubeConfig.Clusters[*clusterPtr].CertificateAuthorityData)),
        kubeConfig.Clusters[*clusterPtr].Server,
      },
      *clusterPtr,
    },
  },
  Contexts: Contexts{
    0: {
      Context{
        Cluster: *clusterPtr,
        User:    *usernamePtr,
      },
      *clusterPtr,
    },
  },
  CurrentContext: *clusterPtr,
  Kind:           "Config",
  Users: Users{
    0: {
      User{
        ClientCertificateData: base64.StdEncoding.EncodeToString(csr.Status.Certificate),
        ClientKeyData:         base64.StdEncoding.EncodeToString(pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: keyDer})),
      },
      *usernamePtr,
    },
  },
}
dir, err := os.Getwd()
check("The following error occured while getting the current working directory %s", err)
_, err = os.Create(filepath.Join(dir, *usernamePtr))
check("The following error occured while creating the target file %s", err)
file, err := os.OpenFile(*usernamePtr, os.O_APPEND|os.O_WRONLY, os.ModeAppend)
check("The following error occured while creating the target Kube Config file", err)
defer file.Close()
e := yaml.NewEncoder(file)
err = e.Encode(kc)
check("The following error occured while writing YAML to the target Kube Config file", err)