Imports k8s.io/apiserver/pkg/authentication/authenticator k8s.io/apiserver/pkg/authentication/user github.com/golang/glog github.com/prometheus/client_golang/prometheus k8s.io/apimachinery/pkg/util/errors k8s.io/apimachinery/pkg/util/sets Standard library imports crypto/x509/pkix crypto/x509 fmt net/http time