package kubernetes import ( "bytes" "context" "crypto/tls" "crypto/x509" "encoding/base32" "encoding/base64" "encoding/json" "errors" "fmt" "hash" "hash/fnv" "io" "io/ioutil" "net" "net/http" "os" "path" "strconv" "strings" "time" "github.com/ghodss/yaml" "github.com/gtank/cryptopasta" "github.com/sirupsen/logrus" "golang.org/x/net/http2" "github.com/coreos/dex/storage" "github.com/coreos/dex/storage/kubernetes/k8sapi" ) type client struct { client *http.Client baseURL string namespace string logger logrus.FieldLogger // Hash function to map IDs (which could span a large range) to Kubernetes names. // While this is not currently upgradable, it could be in the future. // // The default hash is a non-cryptographic hash, because cryptographic hashes // always produce sums too long to fit into a Kubernetes name. Because of this, // gets, updates, and deletes are _always_ checked for collisions. hash func() hash.Hash // API version of the oidc resources. For example "oidc.coreos.com". This is // currently not configurable, but could be in the future. apiVersion string // This is called once the client's Close method is called to signal goroutines, // such as the one creating third party resources, to stop. cancel context.CancelFunc } // idToName maps an arbitrary ID, such as an email or client ID to a Kubernetes object name. func (c *client) idToName(s string) string { return idToName(s, c.hash) } // offlineTokenName maps two arbitrary IDs, to a single Kubernetes object name. // This is used when more than one field is used to uniquely identify the object. func (c *client) offlineTokenName(userID string, connID string) string { return offlineTokenName(userID, connID, c.hash) } // Kubernetes names must match the regexp '[a-z0-9]([-a-z0-9]*[a-z0-9])?'. var encoding = base32.NewEncoding("abcdefghijklmnopqrstuvwxyz234567") func idToName(s string, h func() hash.Hash) string { return strings.TrimRight(encoding.EncodeToString(h().Sum([]byte(s))), "=") } func offlineTokenName(userID string, connID string, h func() hash.Hash) string { hash := h() hash.Write([]byte(userID)) hash.Write([]byte(connID)) return strings.TrimRight(encoding.EncodeToString(hash.Sum(nil)), "=") } func (c *client) urlFor(apiVersion, namespace, resource, name string) string { basePath := "apis/" if apiVersion == "v1" { basePath = "api/" } var p string if namespace != "" { p = path.Join(basePath, apiVersion, "namespaces", namespace, resource, name) } else { p = path.Join(basePath, apiVersion, resource, name) } if strings.HasSuffix(c.baseURL, "/") { return c.baseURL + p } return c.baseURL + "/" + p } // Define an error interface so we can get at the underlying status code if it's // absolutely necessary. For instance when we need to see if an error indicates // a resource already exists. type httpError interface { StatusCode() int } var _ httpError = (*httpErr)(nil) type httpErr struct { method string url string status int body []byte } func (e *httpErr) StatusCode() int { return e.status } func (e *httpErr) Error() string { return fmt.Sprintf("%s %s %s: response from server \"%s\"", e.method, e.url, http.StatusText(e.status), bytes.TrimSpace(e.body)) } func checkHTTPErr(r *http.Response, validStatusCodes ...int) error { for _, status := range validStatusCodes { if r.StatusCode == status { return nil } } body, err := ioutil.ReadAll(io.LimitReader(r.Body, 2<<15)) // 64 KiB if err != nil { return fmt.Errorf("read response body: %v", err) } // Check this case after we read the body so the connection can be reused. if r.StatusCode == http.StatusNotFound { return storage.ErrNotFound } if r.Request.Method == "POST" && r.StatusCode == http.StatusConflict { return storage.ErrAlreadyExists } var url, method string if r.Request != nil { method = r.Request.Method url = r.Request.URL.String() } return &httpErr{method, url, r.StatusCode, body} } // Close the response body. The initial request is drained so the connection can // be reused. func closeResp(r *http.Response) { io.Copy(ioutil.Discard, r.Body) r.Body.Close() } func (c *client) get(resource, name string, v interface{}) error { url := c.urlFor(c.apiVersion, c.namespace, resource, name) resp, err := c.client.Get(url) if err != nil { return err } defer closeResp(resp) if err := checkHTTPErr(resp, http.StatusOK); err != nil { return err } return json.NewDecoder(resp.Body).Decode(v) } func (c *client) list(resource string, v interface{}) error { return c.get(resource, "", v) } func (c *client) post(resource string, v interface{}) error { return c.postResource(c.apiVersion, c.namespace, resource, v) } func (c *client) postResource(apiVersion, namespace, resource string, v interface{}) error { body, err := json.Marshal(v) if err != nil { return fmt.Errorf("marshal object: %v", err) } url := c.urlFor(apiVersion, namespace, resource, "") resp, err := c.client.Post(url, "application/json", bytes.NewReader(body)) if err != nil { return err } defer closeResp(resp) return checkHTTPErr(resp, http.StatusCreated) } func (c *client) delete(resource, name string) error { url := c.urlFor(c.apiVersion, c.namespace, resource, name) req, err := http.NewRequest("DELETE", url, nil) if err != nil { return fmt.Errorf("create delete request: %v", err) } resp, err := c.client.Do(req) if err != nil { return fmt.Errorf("delete request: %v", err) } defer closeResp(resp) return checkHTTPErr(resp, http.StatusOK) } func (c *client) deleteAll(resource string) error { var list struct { k8sapi.TypeMeta `json:",inline"` k8sapi.ListMeta `json:"metadata,omitempty"` Items []struct { k8sapi.TypeMeta `json:",inline"` k8sapi.ObjectMeta `json:"metadata,omitempty"` } `json:"items"` } if err := c.list(resource, &list); err != nil { return err } for _, item := range list.Items { if err := c.delete(resource, item.Name); err != nil { return err } } return nil } func (c *client) put(resource, name string, v interface{}) error { body, err := json.Marshal(v) if err != nil { return fmt.Errorf("marshal object: %v", err) } url := c.urlFor(c.apiVersion, c.namespace, resource, name) req, err := http.NewRequest("PUT", url, bytes.NewReader(body)) if err != nil { return fmt.Errorf("create patch request: %v", err) } req.Header.Set("Content-Length", strconv.Itoa(len(body))) resp, err := c.client.Do(req) if err != nil { return fmt.Errorf("patch request: %v", err) } defer closeResp(resp) return checkHTTPErr(resp, http.StatusOK) } func newClient(cluster k8sapi.Cluster, user k8sapi.AuthInfo, namespace string, logger logrus.FieldLogger, useTPR bool) (*client, error) { tlsConfig := cryptopasta.DefaultTLSConfig() data := func(b string, file string) ([]byte, error) { if b != "" { return base64.StdEncoding.DecodeString(b) } if file == "" { return nil, nil } return ioutil.ReadFile(file) } if caData, err := data(cluster.CertificateAuthorityData, cluster.CertificateAuthority); err != nil { return nil, err } else if caData != nil { tlsConfig.RootCAs = x509.NewCertPool() if !tlsConfig.RootCAs.AppendCertsFromPEM(caData) { return nil, fmt.Errorf("no certificate data found: %v", err) } } clientCert, err := data(user.ClientCertificateData, user.ClientCertificate) if err != nil { return nil, err } clientKey, err := data(user.ClientKeyData, user.ClientKey) if err != nil { return nil, err } if clientCert != nil && clientKey != nil { cert, err := tls.X509KeyPair(clientCert, clientKey) if err != nil { return nil, fmt.Errorf("failed to load client cert: %v", err) } tlsConfig.Certificates = []tls.Certificate{cert} } var t http.RoundTripper httpTransport := &http.Transport{ Proxy: http.ProxyFromEnvironment, Dial: (&net.Dialer{ Timeout: 30 * time.Second, KeepAlive: 30 * time.Second, }).Dial, TLSClientConfig: tlsConfig, TLSHandshakeTimeout: 10 * time.Second, ExpectContinueTimeout: 1 * time.Second, } // Since we set a custom TLS client config we have to explicitly // enable HTTP/2. // // https://github.com/golang/go/blob/go1.7.4/src/net/http/transport.go#L200-L206 if err := http2.ConfigureTransport(httpTransport); err != nil { return nil, err } t = httpTransport if user.Token != "" { t = transport{ updateReq: func(r *http.Request) { r.Header.Set("Authorization", "Bearer "+user.Token) }, base: t, } } if user.Username != "" && user.Password != "" { t = transport{ updateReq: func(r *http.Request) { r.SetBasicAuth(user.Username, user.Password) }, base: t, } } // the API Group and version differ depending on if CRDs or TPRs are used. apiVersion := "dex.coreos.com/v1" if useTPR { apiVersion = "oidc.coreos.com/v1" } logger.Infof("kubernetes client apiVersion = %s", apiVersion) return &client{ client: &http.Client{Transport: t}, baseURL: cluster.Server, hash: func() hash.Hash { return fnv.New64() }, namespace: namespace, apiVersion: apiVersion, logger: logger, }, nil } type transport struct { updateReq func(r *http.Request) base http.RoundTripper } func (t transport) RoundTrip(r *http.Request) (*http.Response, error) { // shallow copy of the struct r2 := new(http.Request) *r2 = *r // deep copy of the Header r2.Header = make(http.Header, len(r.Header)) for k, s := range r.Header { r2.Header[k] = append([]string(nil), s...) } t.updateReq(r2) return t.base.RoundTrip(r2) } func loadKubeConfig(kubeConfigPath string) (cluster k8sapi.Cluster, user k8sapi.AuthInfo, namespace string, err error) { data, err := ioutil.ReadFile(kubeConfigPath) if err != nil { err = fmt.Errorf("read %s: %v", kubeConfigPath, err) return } var c k8sapi.Config if err = yaml.Unmarshal(data, &c); err != nil { err = fmt.Errorf("unmarshal %s: %v", kubeConfigPath, err) return } cluster, user, namespace, err = currentContext(&c) if namespace == "" { namespace = "default" } return } func namespaceFromServiceAccountJWT(s string) (string, error) { // The service account token is just a JWT. Parse it as such. parts := strings.Split(s, ".") if len(parts) < 2 { // It's extremely important we don't log the actual service account token. return "", fmt.Errorf("malformed service account token: expected 3 parts got %d", len(parts)) } payload, err := base64.RawURLEncoding.DecodeString(parts[1]) if err != nil { return "", fmt.Errorf("malformed service account token: %v", err) } var data struct { // The claim Kubernetes uses to identify which namespace a service account belongs to. // // See: https://github.com/kubernetes/kubernetes/blob/v1.4.3/pkg/serviceaccount/jwt.go#L42 Namespace string `json:"kubernetes.io/serviceaccount/namespace"` } if err := json.Unmarshal(payload, &data); err != nil { return "", fmt.Errorf("malformed service account token: %v", err) } if data.Namespace == "" { return "", errors.New(`jwt claim "kubernetes.io/serviceaccount/namespace" not found`) } return data.Namespace, nil } func inClusterConfig() (cluster k8sapi.Cluster, user k8sapi.AuthInfo, namespace string, err error) { host, port := os.Getenv("KUBERNETES_SERVICE_HOST"), os.Getenv("KUBERNETES_SERVICE_PORT") if len(host) == 0 || len(port) == 0 { err = fmt.Errorf("unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined") return } cluster = k8sapi.Cluster{ Server: "https://" + host + ":" + port, CertificateAuthority: "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt", } token, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/token") if err != nil { return } user = k8sapi.AuthInfo{Token: string(token)} if namespace = os.Getenv("KUBERNETES_POD_NAMESPACE"); namespace == "" { namespace, err = namespaceFromServiceAccountJWT(user.Token) if err != nil { err = fmt.Errorf("failed to inspect service account token: %v", err) return } } return } func currentContext(config *k8sapi.Config) (cluster k8sapi.Cluster, user k8sapi.AuthInfo, ns string, err error) { if config.CurrentContext == "" { if len(config.Contexts) == 1 { config.CurrentContext = config.Contexts[0].Name } else { return cluster, user, "", errors.New("kubeconfig has no current context") } } context, ok := func() (k8sapi.Context, bool) { for _, namedContext := range config.Contexts { if namedContext.Name == config.CurrentContext { return namedContext.Context, true } } return k8sapi.Context{}, false }() if !ok { return cluster, user, "", fmt.Errorf("no context named %q found", config.CurrentContext) } cluster, ok = func() (k8sapi.Cluster, bool) { for _, namedCluster := range config.Clusters { if namedCluster.Name == context.Cluster { return namedCluster.Cluster, true } } return k8sapi.Cluster{}, false }() if !ok { return cluster, user, "", fmt.Errorf("no cluster named %q found", context.Cluster) } user, ok = func() (k8sapi.AuthInfo, bool) { for _, namedAuthInfo := range config.AuthInfos { if namedAuthInfo.Name == context.AuthInfo { return namedAuthInfo.AuthInfo, true } } return k8sapi.AuthInfo{}, false }() if !ok { return cluster, user, "", fmt.Errorf("no user named %q found", context.AuthInfo) } return cluster, user, context.Namespace, nil }