/* Copyright 2019 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/promhttp" "go.uber.org/zap" "k8s.io/client-go/kubernetes" ) const ( // Version is the server version Version = "v0.0.4" // 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 authorizer == nil { return nil, errors.New("no authorizer") } if err := config.IsValid(); err != nil { return nil, fmt.Errorf("configuration error: %s", err) } 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", promhttp.Handler()).Methods(http.MethodGet) r.HandleFunc("/health", n.healthHandler).Methods(http.MethodGet) server.Handler = recovery(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, 1) 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 != "" }