kops/node-authorizer/pkg/server/server.go

133 lines
3.4 KiB
Go

/*
Copyright 2018 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package server
import (
"crypto/tls"
"crypto/x509"
"errors"
"fmt"
"io/ioutil"
"net/http"
"os"
"os/signal"
"syscall"
"k8s.io/kops/node-authorizer/pkg/utils"
"github.com/gorilla/mux"
"github.com/prometheus/client_golang/prometheus"
"go.uber.org/zap"
"k8s.io/client-go/kubernetes"
)
const (
// Version is the server version
Version = "v0.0.1"
// the namespace to place the secrets
tokenNamespace = "kube-system"
)
// NodeAuthorizer retains the authorizer state
type NodeAuthorizer struct {
// authorizer is a collection of authorizers
authorizer Authorizer
// client is the kubernetes api client
client kubernetes.Interface
// config is the configuration
config *Config
}
// New creates and returns a node authorizer
func New(config *Config, authorizer Authorizer) (*NodeAuthorizer, error) {
utils.Logger.Info("starting the node authorization service",
zap.String("listen", config.Listen),
zap.String("version", Version))
if err := config.IsValid(); err != nil {
return nil, fmt.Errorf("configuration error: %s", err)
}
if authorizer == nil {
return nil, errors.New("no authorizer")
}
return &NodeAuthorizer{
authorizer: authorizer,
config: config,
}, nil
}
// Run is responsible for starting the node authorizer service
func (n *NodeAuthorizer) Run() error {
// @step: create the kubernetes client
client, err := utils.GetKubernetesClient()
if err != nil {
return err
}
n.client = client
// @step: create the http service
server := &http.Server{
Addr: n.config.Listen,
TLSConfig: &tls.Config{
MinVersion: tls.VersionTLS12,
PreferServerCipherSuites: true,
},
}
// @step: are we using mutual tls?
if n.config.TLSClientCAPath != "" {
// a client certificate is not required, but if given we need to verify it
server.TLSConfig.ClientAuth = tls.VerifyClientCertIfGiven
caCert, err := ioutil.ReadFile(n.config.TLSClientCAPath)
if err != nil {
return err
}
caCertPool := x509.NewCertPool()
caCertPool.AppendCertsFromPEM(caCert)
server.TLSConfig.ClientCAs = caCertPool
}
// @step: add the routing
r := mux.NewRouter()
r.Handle("/authorize/{name}", authorized(n.authorizeHandler, n.config.ClientCommonName, n.useMutualTLS())).Methods(http.MethodPost)
r.Handle("/metrics", prometheus.Handler()).Methods(http.MethodGet)
r.HandleFunc("/health", n.healthHandler).Methods(http.MethodGet)
server.Handler = r
// @step: wait for either an error or a termination signal
errs := make(chan error, 2)
go func() {
errs <- server.ListenAndServeTLS(n.config.TLSCertPath, n.config.TLSPrivateKeyPath)
}()
go func() {
c := make(chan os.Signal)
signal.Notify(c, syscall.SIGINT)
errs <- fmt.Errorf("received termination signal: %s", <-c)
}()
return <-errs
}
// useMutualTLS checks if we are using mutual tls
func (n *NodeAuthorizer) useMutualTLS() bool {
return n.config.TLSClientCAPath != ""
}