DefaultCfgDir     = "./var/lib/istio/envoy/envoy_bootstrap_tmpl.json"
)

// TODO(nmittler): Move this to application code. This shouldn't be declared in a library.
var overrideVar = env.Register("ISTIO_BOOTSTRAP", "", "")

// Instance of a configured Envoy bootstrap writer.
type Instance interface {
	// WriteTo writes the content of the Envoy bootstrap to the given writer.
	WriteTo(templateFile string, w io.Writer) error