While the kubernetes golang api example for out-of-cluster authentication works fine, and creating a service account and exporting the bearer token works great, it feels silly to write the pieces to a temporary file only to tell the API to read it. Is there an API way to pass these pieces as an object rather than write to a file?

    clusterData := map[string]string{
        "BEARER_TOKEN":       bearerToken,
        "CA_DATA":            clusterCA,
        "ENDPOINT":           clusterUrl,
    }

    const kubeConfigTmpl = `
apiVersion: v1
clusters:
    - cluster:
    certificate-authority-data: {{.CA_DATA}}
server: {{.HOST_IP_ADDRESS}}
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    namespace: default
    user: lamdba-serviceaccount-default-kubernetes
  name: lamdba-serviceaccount-default-kubernetes
current-context: lamdba-serviceaccount-default-kubernetes
kind: Config
preferences: {}
users:
- name: lamdba-serviceaccount-default-kubernetes
  user:
    token: {{.BEARER_TOKEN}}
`
    t := template.Must(template.New("registration").Parse(kubeConfigTmpl))
    buf := &bytes.Buffer{}
    if err := t.Execute(buf, clusterData); err != nil {
        panic(err)
    }
    registrationPayload := buf.String()

    d1 := []byte(registrationPayload)
    err := ioutil.WriteFile("/tmp/config", d1, 0644)