caProviderEnv = env.Register("CA_PROVIDER", "Citadel", "name of authentication provider").Get()
	caEndpointEnv = env.Register("CA_ADDR", "", "Address of the spiffe certificate provider. Defaults to discoveryAddress").Get()

	trustDomainEnv = env.Register("TRUST_DOMAIN", "cluster.local",
		"The trust domain for spiffe certificates").Get()

	secretTTLEnv = env.Register("SECRET_TTL", 24*time.Hour,

a new one will be generated on demand.

## Configuration

| Variable | Description |
| - | - |
|CA_ADDR|Address of CA, defaults to discoveryAddress|
|CA_PROVIDER|Type of CA; supported values are GoogleCA or Citadel (although anything but GoogleCA will use Citadel); defaults to Citadel|